Randy Dunlap [Wed, 17 Jun 2026 16:31:25 +0000 (09:31 -0700)]
slab: recognize @GFP parameter as optional in kernel-doc
Since the @GFP parameter in kmalloc_obj() etc. is now optional, change
the kernel-doc to indicate that it is optional. This avoids kernel-doc
warnings:
WARNING: include/linux/slab.h:1101 Excess function parameter 'GFP' description in 'kmalloc_obj'
WARNING: include/linux/slab.h:1113 Excess function parameter 'GFP' description in 'kmalloc_objs'
WARNING: include/linux/slab.h:1128 Excess function parameter 'GFP' description in 'kmalloc_flex'
Fixes: e19e1b480ac7 ("add default_gfp() helper macro and use it in the new *alloc_obj() helpers") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Harry Yoo (Oracle) <harry@kernel.org> Link: https://patch.msgid.link/20260617163125.2716279-1-rdunlap@infradead.org Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
mm/slab: replace __GFP_NO_OBJ_EXT with SLAB_ALLOC_NO_RECURSE for sheaves
Finish the switch away from __GFP_NO_OBJ_EXT by replacing it with
SLAB_ALLOC_NO_RECURSE when allocating empty sheaves. Pass alloc_flags to
[__]alloc_empty_sheaf(). Callers that can't be part of a recursive
kmalloc() chain simply pass SLAB_ALLOC_DEFAULT. Use kmalloc_flags()
instead of kzalloc() for allocating the sheaf.
With that we can finalize the removal the __GFP_NO_OBJ_EXT handling from
obj_ext allocations as well, leaving only SLAB_ALLOC_NO_RECURSE in
place.
This leaves __GFP_NO_OBJ_EXT with no users in slab, so stop allowing the
flag in kmalloc_nolock().
mm/slab: remove __GFP_NO_OBJ_EXT usage from alloc_slab_obj_exts()
__GFP_NO_OBJ_EXT has limited scope within the slab allocator itself and
gfp flags are a scarce resource, unlike slab's alloc_flags.
Introduce SLAB_ALLOC_NO_RECURSE alloc flag that has the same intent as
__GFP_NO_OBJ_EXT but a more generic name, meaning that a kmalloc()
family function should not recurse into another kmalloc*() for the
purposes of allocating auxiliary structures (obj_ext arrays or sheaves).
First, replace the __GFP_NO_OBJ_EXT for allocating obj_ext arrays in
alloc_slab_obj_exts(). Make use of the newly added kmalloc_flags()
function, where we can pass alloc_flags with SLAB_ALLOC_NO_RECURSE
added. This will also pass through SLAB_ALLOC_NOLOCK so we don't need
to special case kmalloc_nolock() anymore.
Note that until now the kmalloc_nolock() ignored the incoming gfp flags
and hardcoded __GFP_ZERO | __GFP_NO_OBJ_EXT. But it's correct to pass on
the incoming gfp flags (only augmented with __GFP_ZERO), because if
alloc_flags contain SLAB_ALLOC_NOLOCK, the incoming gfp flags have to
be also compatible with it. However, we might have added __GFP_THISNODE
for opportunistic slab allocation, as pointed out by Hao Li, and
__GFP_COMP by allocate_slab() as pointed out by Shengming Hu. Solve this
by adding both flags to OBJCGS_CLEAR_MASK as it makes sense to strip
them anyway for non-kmalloc_nolock() allocations of sheaves or obj_ext
arrays as well.
To avoid recursion of sheaf -> obj_ext -> sheaf -> ... allocations at
this patch, until the next patch converts sheaves to
SLAB_ALLOC_NO_RECURSE, use both gfp and alloc_flags for obj_ext. The
next patch will remove the gfp part.
With alloc_flags usage in slab, we can replace __GFP_NO_OBJ_EXT with an
alloc flag that prevents kmalloc recursion. For that we need a version
of kmalloc() that takes alloc_flags and use it in places that perform
these potentially recursive kmalloc allocations (of sheaves or obj_ext
arrays).
Add this function, named kmalloc_flags(). Right now it's only useful for
these nested allocations, so it doesn't need to optimize build-time
constant sizes like kmalloc() or kmalloc_buckets.
Since we need it to support both normal and non-spinning
kmalloc_nolock() context through the SLAB_ALLOC_NOLOCK flag, split out
most of the special _kmalloc_nolock_noprof() implementation to
__kmalloc_nolock_noprof() that takes a slab_alloc_context, and make
_kmalloc_nolock_noprof() a simple tail calling wrapper with the proper
context.
kmalloc_flags() can thus determine whether to call
__kmalloc_nolock_noprof() or __do_kmalloc_node(), based on the
given alloc_flags.
mm/slab: allow __GFP_NOMEMALLOC and __GFP_NOWARN for kmalloc_nolock()
The two flags are added internally so there's no point for warning if
they are passed by the caller as well, so allow them. This will allow
simplifying obj_ext allocation under kmalloc_nolock().
Also it's not necessary to have the extra alloc_gfp variable for adding
the two flags. The original gfp_flags parameter is not used anywhere
except for the warning. So remove alloc_gfp and directly modify and use
gfp_flags everywhere.
mm/slab: pass slab_alloc_context to __do_kmalloc_node()
With alloc_flags usage in slab, we can replace __GFP_NO_OBJ_EXT with an
alloc flag that prevents kmalloc recursion. For that we need a version
of kmalloc() that takes alloc_flags and use it in places that perform
these potentially recursive kmalloc allocations (of sheaves or obj_ext
arrays).
As a preparatory step, make __do_kmalloc_node() take a pointer to
slab_alloc_context. This replaces the 'size' and 'caller' parameters and
includes alloc_flags which we'll make use of.
mm/slab: allow kmem_cache_alloc_bulk() with any gfp flags
The last user of gfpflags_allow_spinning() in slab is
alloc_from_pcs_bulk(), which is only called from
kmem_cache_alloc_bulk().
It turns out that gfpflags_allow_spinning() is not necessary, because
kmem_cache_alloc_bulk() is only expected to be called from context that
does allow spinning, so simply replace it with 'true'. This means we can
also drop the gfp parameter from alloc_from_pcs_bulk().
With that, we can remove the "@flags must allow spinning" part of the
kernel doc, as there is no more connection to the gfp flags in the slab
implementation.
Also remove a comment in alloc_slab_obj_exts() because there should be
no more false positives possible due to gfp_allowed_mask during early
boot.
mm/slab: replace slab_alloc_node() parameters with slab_alloc_context
The function takes all the parameters that exist as fields in
slab_alloc_context, except alloc_flags. Replace them with a single
pointer.
This moves slab_alloc_context initialization to a number of callers,
which is more verbose, but arguably also more clear than a long list of
parameters, and most do not use the 'lru' field.
This will also allow kmalloc_nolock() to call slab_alloc_node() and
reduce the special open-coding it currently has.
Converting all these at once avoids unnecessary churn and is mostly
mechanical.
This ultimately allows to decide if spinning is allowed using
alloc_flags in alloc_slab_obj_exts(), as well as slab_post_alloc_hook().
Aside from alloc_from_pcs_bulk() (to be handled next) there is nothing
else in slab itself relying on gfpflags_allow_spinning() which can
be false even if not called from kmalloc_nolock().
A followup change will also use the alloc_flags availability in the call
stack above to remove the __GFP_NO_OBJ_EXT flag.
For alloc_slab_obj_exts(), also replace the suboptimal "bool new_slab"
parameter with a SLAB_ALLOC_NEW_SLAB flag with identical functionality.
To further reduce the number of parameters of slab_post_alloc_hook(),
also make 'struct list_lru *lru' (which is NULL for most callers) a new
field of slab_alloc_context.
Add alloc_flags as a new field to the slab_alloc_context helper struct,
so we can pass it to more functions in the slab implementation without
adding another function parameter.
Start checking them via alloc_flags_allow_spinning() in
alloc_single_from_new_slab() (where we can drop the allow_spin
parameter), ___slab_alloc(), get_from_partial_node() and
get_from_any_partial(). This further reduces false-positive
spinning-not-allowed from allocations that are not kmalloc_nolock() but
lack __GFP_RECLAIM flags.
_kmalloc_nolock_noprof() initializes ac.alloc_flags using its flags that
are SLAB_ALLOC_NOLOCK. slab_alloc_node() and __kmem_cache_alloc_bulk()
are not reachable from kmalloc_nolock() and all their callers expect
spinning to be allowed, so they can use SLAB_ALLOC_DEFAULT. This is
temporary as the scope of slab_alloc_context will further move to the
callers, making the alloc_flags usage more obvious.
Also change how trynode_flags are constructed in ___slab_alloc() to
achieve the same "do not upgrade to GFP_NOWAIT" by using masking instead
of checking allow_spin. We need to do that because we now determine
allow_spin from alloc_flags, and would otherwise start to upgrade e.g.
kmalloc() allocations without __GFP_KSWAPD_RECLAIM (that however do
allow spinning) to GFP_NOWAIT, thus including __GFP_KSWAPD_RECLAIM.
During the masking keep also existing __GFP_NOMEMALLOC (pointed out by
Sashiko) and __GFP_ACCOUNT. Previously the hardcoded GFP_NOWAIT would
eliminate them, but it's not a big problem that would need a separate
fix.
mm/slab: replace struct partial_context with slab_alloc_context
Refactor get_from_partial_node(), get_from_any_partial(),
get_from_partial() and ___slab_alloc().
Remove struct partial_context, which used to be more substantial but
shrank as part of the sheaves conversion. Instead pass gfp_flags and
pointer to the new slab_alloc_context, which together is a superset of
partial_context, and alloc_flags are about to be added to
slab_alloc_context as well.
mm/slab: introduce alloc_flags and SLAB_ALLOC_NOLOCK
Similarly to the page allocators, introduce slab-allocator specific
alloc flags that internally control allocation behavior in addition to
gfp_flags, without occupying the limited gfp flags space.
Introduce the first flag SLAB_ALLOC_NOLOCK that behaves similarly to
page allocator's ALLOC_TRYLOCK and will be used to reimplement
kmalloc_nolock()'s "!allow_spin" behavior. That currently relies on
gfpflags_allow_spinning() and thus the lack of both __GFP_RECLAIM flags,
importantly __GFP_KSWAPD_RECLAIM. This can give false-positive results
e.g. in early boot with a restricted gfp_allowed_mask.
Also introduce alloc_flags_allow_spinning() to replace the usage of
gfpflags_allow_spinning().
Start using alloc_flags and the new check first in alloc_from_pcs() and
__pcs_replace_empty_main(). This means some slab allocations that were
falsely treated as kmalloc_nolock() due to their gfp flags will now have
higher chances of success, and this will further increase with followup
changes.
Remove a WARN_ON_ONCE() from refill_objects() as it's now legitimate to
reach it from a slab allocation that's not _nolock() and yet lacks
__GFP_KSWAPD_RECLAIM for other reasons.
Similarly to page allocator's struct alloc_context, introduce a helper
struct to hold a part of the allocation arguments. This will allow
reducing the number of parameters in many functions of the
implementation, and extend them easily if needed.
For now, make it hold the caller address and the originally requested
allocation size.
Convert alloc_single_from_new_slab(), __slab_alloc_node() and
___slab_alloc(). No functional change intended.
mm/slab: do not init any kfence objects on allocation
When init (zeroing) on allocation is requested, for kmalloc() we
generally have to zero the full object size even if a smaller size is
requested, in order to provide krealloc()'s __GFP_ZERO guarantees.
When we end up allocating a kfence object, kfence performs the zeroing
on its own because it has its own redzone beyond the requested size.
Thus slab_post_alloc_hook() has an 'init' parameter which has to be
evaluated in all callers (via slab_want_init_on_alloc()) and should be
false for kfence allocations.
For kfence allocations in slab_alloc_node() this is achieved by subtly
skipping over the slab_want_init_on_alloc() call. Other callers (i.e.
kmem_cache_alloc_bulk_noprof()) however evaluate it unconditionally even
if they do end up with a kfence allocation. This is only subtly not a
problem, as those are not kmalloc allocations and thus the "requested
size" equals s->object_size and thus it cannot interfere with kfence's
redzone. There's just a unnecessary double zeroing (in both kfence and
slab_post_alloc_hook()), but it's all very fragile and contradicts the
comment in kfence_guarded_alloc().
Remove this subtlety and simplify the code by eliminating the init
parameter from slab_post_alloc_hook() and make it call
slab_want_init_on_alloc() itself. Instead add a is_kfence_address()
check before performing the memset, which will start doing the right
thing for all callers of slab_post_alloc_hook().
This potentially adds overhead of the is_kfence_address() check to
allocation hotpath, but that one is designed to be as small as possible,
and it's only evaluated if zeroing is about to happen. This means (aside
from init_on_alloc hardening) only for __GFP_ZERO allocations, and the
zeroing itself comes with an overhead likely larger than the added
check.
While at it, refactor the handling of evaluating when KASAN does the
init instead of SLUB, with no intended functional changes. A
non-functional change is that we don't pass kasan_init as true to
kasan_slab_alloc() if kasan has no integrated init, but then the value
is ignored anyway, so it's theoretically more correct.
Thanks to Harry Yoo for the initial refactoring attempt, and for updated
comments that are used here.
Link: https://patch.msgid.link/20260610-slab_alloc_flags-v2-2-7190909db118@kernel.org Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Hao Li <hao.li@linux.dev> Reviewed-by: Marco Elver <elver@google.com> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Merge branch 'slab/for-7.2/alloc_token' into slab/for-next
Merge series "slab: support for compiler-assisted type-based slab cache
partitioning" from Marco Elver. From the cover letter [6]:
Rework the general infrastructure around RANDOM_KMALLOC_CACHES into more
flexible KMALLOC_PARTITION_CACHES, with the former being a partitioning
mode of the latter.
Introduce a new mode, KMALLOC_PARTITION_TYPED, which leverages a feature
available in Clang 22 and later, called "allocation tokens" via
__builtin_infer_alloc_token() [1]. Unlike KMALLOC_PARTITION_RANDOM
(formerly RANDOM_KMALLOC_CACHES), this mode deterministically assigns a
slab cache to an allocation of type T, regardless of allocation site.
The builtin __builtin_infer_alloc_token(<malloc-args>, ...) instructs
the compiler to infer an allocation type from arguments commonly passed
to memory-allocating functions and returns a type-derived token ID. The
implementation passes kmalloc-args to the builtin: the compiler performs
best-effort type inference, and then recognizes common patterns such as
`kmalloc(sizeof(T), ...)`, `kmalloc(sizeof(T) * n, ...)`, but also
`(T *)kmalloc(...)`. Where the compiler fails to infer a type the
fallback token (default: 0) is chosen.
Note: kmalloc_obj(..) APIs fix the pattern how size and result type are
expressed, and therefore ensures there's not much drift in which
patterns the compiler needs to recognize. Specifically, kmalloc_obj()
and friends expand to `(TYPE *)KMALLOC(__obj_size, GFP)`, which the
compiler recognizes via the cast to TYPE*.
Clang's default token ID calculation is described as [1]:
typehashpointersplit: This mode assigns a token ID based on the hash
of the allocated type's name, where the top half ID-space is reserved
for types that contain pointers and the bottom half for types that do
not contain pointers.
Separating pointer-containing objects from pointerless objects and data
allocations can help mitigate certain classes of memory corruption
exploits [2]: attackers who gains a buffer overflow on a primitive
buffer cannot use it to directly corrupt pointers or other critical
metadata in an object residing in a different, isolated heap region.
It is important to note that heap isolation strategies offer a
best-effort approach, and do not provide a 100% security guarantee,
albeit achievable at relatively low performance cost. Note that this
also does not prevent cross-cache attacks: while waiting for future
features like SLAB_VIRTUAL [3] to provide physical page isolation, this
feature should be deployed alongside SHUFFLE_PAGE_ALLOCATOR and
init_on_free=1 to mitigate cross-cache attacks and page-reuse attacks as
much as possible today.
With all that, my kernel (x86 defconfig) shows me a histogram of slab
cache object distribution per /proc/slabinfo (after boot):
The above /proc/slabinfo snapshot shows me there are 6673 allocated
objects (slabs 00 - 07) that the compiler claims contain no pointers or
it was unable to infer the type of, and 12015 objects that contain
pointers (slabs 08 - 15). On a whole, this looks relatively sane.
Additionally, when I compile my kernel with -Rpass=alloc-token, which
provides diagnostics where (after dead-code elimination) type inference
failed, I see 186 allocation sites where the compiler failed to identify
a type (down from 966 when I sent the RFC [4]). Some initial review
confirms these are mostly variable sized buffers, but also include
structs with trailing flexible length arrays.
Merge branch 'slab/for-7.2/alloc_bulk' into slab/for-next
Merge two separately sent but vaguely related patches from Christoph
Hellwig. One changes the kmem_cache_alloc_bulk() API to return bool,
because it was already actiong as all-or-nothing, and that aspect was
not documented. Existing callers are updated.
The second patch simplifies the mempool_alloc_bulk() API to stop
skipping over non-NULL entries in the array, and removes a related
parameter that said how many are non-NULL.
A similar simplification of alloc_pages_bulk() is being discussed as
well and should follow in near future.
mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
When init (zeroing) on allocation is requested, for kmalloc() we
generally have to zero the full object size even if a smaller size is
requested, in order to provide krealloc()'s __GFP_ZERO guarantees.
But if we track the requested size, krealloc() uses that information to
do the right thing, so we can zero only the requested size. With red
zoning also enabled, any extra size became part of the red zone, so it
must not be zeroed and thus we must zero only the requested size.
However the current check is imprecise, and will trigger also when only
SLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking
the requested size). This means enabling red zoning alone can compromise
krealloc()'s __GFP_ZERO contract.
Fix this by using slub_debug_orig_size() instead, which is the exact
check for whether the requested size is tracked. We don't need to care
if red zoning is also enabled or not. Also update and expand the
comment accordingly.
Fixes: 9ce67395f5a0 ("mm/slub: only zero requested size of buffer for kzalloc when debug enabled") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260610-slab_alloc_flags-v2-1-7190909db118@kernel.org Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org> Reviewed-by: Hao Li <hao.li@linux.dev> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Shengming Hu [Thu, 4 Jun 2026 12:27:32 +0000 (20:27 +0800)]
mm/slub: preserve original size in _kmalloc_nolock_noprof retry path
_kmalloc_nolock_noprof() retries from the next kmalloc bucket when the
initial allocation fails. The retry currently reuses `size` as the
bucket selector and overwrites it with s->object_size + 1.
That value is later passed as the original allocation size to
__slab_alloc_node(), slab_post_alloc_hook() and kasan_kmalloc(). On a
successful retry this makes KASAN/slub-debug observe the retry bucket
selector rather than the caller requested size, potentially widening the
valid kmalloc range and hiding overflows.
Keep the caller requested size separately as orig_size and pass it to
the allocation/debug/KASAN paths. Continue using `size` as the retry cache
selector.
Fixes: af92793e52c3 ("slab: Introduce kmalloc_nolock() and kfree_nolock()") Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn> Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org> Reviewed-by: Hao Li <hao.li@linux.dev> Link: https://patch.msgid.link/202606042027323804pk3MRY42Jy7y42OHAhQZ@zte.com.cn Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
The mempool_alloc_bulk was modelled after the alloc_pages_bulk API,
including some misunderstanding of it.
Remove checking for NULL slots in the array, as alloc_pages_bulk and
kmem_cache_alloc_bulk always fill the array from the beginning and thus
we know the offset of the first failing allocation. This removes support
for working well with alloc_pages_bulk used to refill page arrays that
might have an entry removed from in the middle, but that is only used by
sunrpc and hopefully on it's way out.
Also remove the allocated parameter as it is redundant because the caller
can simply specific and offset into the entries array.
The kmem_cache_alloc_bulk return value is weird. It returns the number
of allocated objects, but that must always be 0 or the requested number
based on the implementations and the handling in the callers, but that
assumption is not actually documented anywhere, which confuses automated
review tools.
Fix this by returning a bool if the allocation succeeded and adding a
kerneldoc comment explaining the API.
[rob.clark@oss.qualcomm.com: fixups in
msm_iommu_pagetable_prealloc_allocate() ]
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> # skbuff Link: https://patch.msgid.link/20260528093437.2519248-2-hch@lst.de Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Hao Li [Fri, 29 May 2026 03:50:52 +0000 (11:50 +0800)]
mm/slub: detach and reattach partial slabs in batch
get_partial_node_bulk() moves each selected slab from the node's
partial list to the local pc->slabs list using a remove_partial() and
list_add() pair. In practice, the loop often detaches several adjacent
slabs. Doing this individually repeatedly manipulates list pointers
while holding n->list_lock, which causes unnecessary churn.
To demonstrate this, the counts below show how often single vs. multiple
consecutive slabs are retrieved during a will-it-scale mmap stress test:
The data confirms that retrieving multiple contiguous slabs is highly
frequent.
To optimize this, track contiguous runs of matching slabs and move each
run in a single operation using list_bulk_move_tail(). This reduces list
pointer churn inside the lock critical section.
Apply the same optimization to __refill_objects_node() when reattaching
leftover partial slabs back to the node's partial list.
The will-it-scale mmap benchmark shows a 2% ~ 5% performance improvement
after applying this patch.
Hao Li [Fri, 29 May 2026 03:50:51 +0000 (11:50 +0800)]
mm/slub: introduce helpers for node partial slab state
Wrap partial slab count inc/dec and flag set/clear into
helper functions to reduce code duplication.
Note that __add_partial() is called locklessly in
early_kmem_cache_node_alloc(), but since there is no such use case for
removal, __remove_partial() does not exist.
Suggested-by: Harry Yoo <harry@kernel.org> Signed-off-by: Hao Li <hao.li@linux.dev> Link: https://patch.msgid.link/20260529035120.81304-2-hao.li@linux.dev Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Shengming Hu [Thu, 28 May 2026 11:35:37 +0000 (19:35 +0800)]
mm/slub: use empty sheaf helpers for oversized sheaves
Oversized prefilled sheaves are allocated separately because their
capacity can be larger than the cache's regular sheaf capacity. After
they are flushed, however, they are empty sheaves as well, and should be
released through the same empty-sheaf helper.
Allocate oversized prefilled sheaves with __alloc_empty_sheaf() and free
them with free_empty_sheaf() after a failed prefill or after they are
returned and flushed. This keeps the oversized and pfmemalloc return paths
consistent, including the SLAB_KMALLOC-specific __GFP_NO_OBJ_EXT and
mark_obj_codetag_empty() handling.
Keep the caller-GFP filtering in alloc_empty_sheaf() instead of
__alloc_empty_sheaf(). In particular, do not clear OBJCGS_CLEAR_MASK in
the raw helper, so the oversized prefill path does not unexpectedly drop
caller-provided flags such as __GFP_NOFAIL. The SLAB_KMALLOC-specific
addition of __GFP_NO_OBJ_EXT remains in __alloc_empty_sheaf(), matching
the free_empty_sheaf() assumption.
Since oversized sheaves are now allocated and freed through the empty
sheaf helpers, SHEAF_ALLOC and SHEAF_FREE also account for oversized
sheaves. Update the stat comments accordingly.
Keep the capacity initialization in the oversized prefill path, since
capacity is currently only used for prefilled sheaves
slab->partial is assigned by get_obj("partial") and then immediately
overwritten by get_obj_and_str("partial", &t). Remove the first
redundant assignment.
Xuewen Wang [Mon, 18 May 2026 06:21:58 +0000 (14:21 +0800)]
tools/mm/slabinfo: remove dead assignment in get_obj_and_str()
The assignment `x = NULL` sets the local parameter variable instead of
`*x`, which is a no-op since `*x` was already set to NULL on the line
above. Remove the dead assignment.
The disable trace path in slab_debug() had a logic error where it would
set trace=1 instead of trace=0. This made trace functionality permanently
enabled once turned on for any slab cache.
mm, slab: simplify returning slab in __refill_objects_node()
When we return slabs to the partial list because we didn't fully refill
from them, we observe the min_partial limit when the returned slab is
empty, and discard it when over the limit. But it's unlikely for the
limit to be reached while we were refilling, and the worst outcome is to
have temporarily more free slabs on the list than necessary. So just
drop that code and simplify the function.
mm, slab: add an optimistic __slab_try_return_freelist()
When we end up returning extraneous objects during refill to a slab
where we just did a get_freelist_nofreeze(), it is likely no other CPU
has freed objects to it meanwhile. We can then reattach the remainder of
the freelist without having to walk the (potentially cache cold)
freelist for finding its tail to connect slab->freelist to it.
Add a __slab_try_return_freelist() function that does that. As suggested
by Hao Li, it doesn't need to also return the slab to the partial list,
because there's code in __refill_objects_node() that already does that
for any slabs where we don't detach the freelist in the first place. So
we just put the slab back to the pc.slabs list. It's no longer likely
that the list will be empty now, so remove the unlikely() annotation.
However, also change that code to add to the tail of the partial list
instead of head to match what __slab_free() did and avoid a regression,
that was reported for the earlier version by the kernel test robot [1].
This change will also affect slabs which were grabbed from the partial
list and not refilled from even partially, but those should be much more
rare than a partial refill.
Marco Elver [Mon, 11 May 2026 20:00:50 +0000 (22:00 +0200)]
slab: fix kernel-docs for mm-api
The mm-api kernel-docs have been disconnected from their symbols. While
the scripts were previously taught to handle the _noprof suffix added by
allocation tagging (in 51a7bf0238c2 "scripts/kernel-doc: drop "_noprof"
on function prototypes"), this does not handle cases where the internal
implementation function has an additional leading underscore. The added
optional parameters (via DECL_KMALLOC_PARAMS) further complicate parsing
the internal signatures.
When the kernel-doc block remains above the internal implementation
function but uses the public API name, the documentation generator fails
to associate the documented symbol.
Simply moving the docs to the macros in slab.h fixes the association but
causes loss of types in the generated documentation (rendering as e.g.
untyped 'kmalloc(size, flags)' macro).
Fix this by:
1. Moving the kernel-doc comment blocks from slub.c to slab.h, placing
them directly above the user-facing macros.
2. Providing explicit, typed C prototypes for the documented APIs inside
'#if 0 /* kernel-doc */' blocks.
3. Converting the variadic macros for the documented APIs to use
explicit arguments to match the documentation.
Marco Elver [Mon, 11 May 2026 20:00:49 +0000 (22:00 +0200)]
slab: improve KMALLOC_PARTITION_RANDOM randomness
When using CONFIG_KMALLOC_PARTITION_RANDOM, _RET_IP_ was previously used
to identify the allocation site. _RET_IP_, however, evaluates to the
caller's parent's instruction pointer rather than the actual allocation
site; this would lead to collisions where a function performs multiple
allocations.
With the generalization to kmalloc_token_t, we now generate the token at
the outermost macro, and using _THIS_IP_ would fix this for all cases.
Unfortunately, the generic implementation of _THIS_IP_ relies on taking
the address of a local label, which is considered broken by both GCC [1]
and Clang [2] because label addresses are only expected to be used with
computed gotos. While the generic version more or less works today, it
is known to be brittle. For example, Clang -O2 always returns 1 when
this function is inlined:
To provide a reliable unique identifier without breaking architectures
relying on the generic _THIS_IP_, introduce _CODE_LOCATION_: it resolves
to _THIS_IP_ where architectures provide a safe implementation, and
falls back to a zero-cost static marker where _THIS_IP_ is broken.
Marco Elver [Mon, 11 May 2026 20:00:48 +0000 (22:00 +0200)]
slab: support for compiler-assisted type-based slab cache partitioning
Rework the general infrastructure around RANDOM_KMALLOC_CACHES into more
flexible KMALLOC_PARTITION_CACHES, with the former being a partitioning
mode of the latter.
Introduce a new mode, KMALLOC_PARTITION_TYPED, which leverages a feature
available in Clang 22 and later, called "allocation tokens" via
__builtin_infer_alloc_token() [1]. Unlike KMALLOC_PARTITION_RANDOM
(formerly RANDOM_KMALLOC_CACHES), this mode deterministically assigns a
slab cache to an allocation of type T, regardless of allocation site.
The builtin __builtin_infer_alloc_token(<malloc-args>, ...) instructs
the compiler to infer an allocation type from arguments commonly passed
to memory-allocating functions and returns a type-derived token ID. The
implementation passes kmalloc-args to the builtin: the compiler performs
best-effort type inference, and then recognizes common patterns such as
`kmalloc(sizeof(T), ...)`, `kmalloc(sizeof(T) * n, ...)`, but also
`(T *)kmalloc(...)`. Where the compiler fails to infer a type the
fallback token (default: 0) is chosen.
Note: kmalloc_obj(..) APIs fix the pattern how size and result type are
expressed, and therefore ensures there's not much drift in which
patterns the compiler needs to recognize. Specifically, kmalloc_obj()
and friends expand to `(TYPE *)KMALLOC(__obj_size, GFP)`, which the
compiler recognizes via the cast to TYPE*.
Clang's default token ID calculation is described as [1]:
typehashpointersplit: This mode assigns a token ID based on the hash
of the allocated type's name, where the top half ID-space is reserved
for types that contain pointers and the bottom half for types that do
not contain pointers.
Separating pointer-containing objects from pointerless objects and data
allocations can help mitigate certain classes of memory corruption
exploits [2]: attackers who gains a buffer overflow on a primitive
buffer cannot use it to directly corrupt pointers or other critical
metadata in an object residing in a different, isolated heap region.
It is important to note that heap isolation strategies offer a
best-effort approach, and do not provide a 100% security guarantee,
albeit achievable at relatively low performance cost. Note that this
also does not prevent cross-cache attacks: while waiting for future
features like SLAB_VIRTUAL [3] to provide physical page isolation, this
feature should be deployed alongside SHUFFLE_PAGE_ALLOCATOR and
init_on_free=1 to mitigate cross-cache attacks and page-reuse attacks as
much as possible today.
With all that, my kernel (x86 defconfig) shows me a histogram of slab
cache object distribution per /proc/slabinfo (after boot):
The above /proc/slabinfo snapshot shows me there are 6673 allocated
objects (slabs 00 - 07) that the compiler claims contain no pointers or
it was unable to infer the type of, and 12015 objects that contain
pointers (slabs 08 - 15). On a whole, this looks relatively sane.
Additionally, when I compile my kernel with -Rpass=alloc-token, which
provides diagnostics where (after dead-code elimination) type inference
failed, I see 186 allocation sites where the compiler failed to identify
a type (down from 966 when I sent the RFC [4]). Some initial review
confirms these are mostly variable sized buffers, but also include
structs with trailing flexible length arrays.
Shengming Hu [Thu, 30 Apr 2026 14:04:41 +0000 (22:04 +0800)]
mm/slub: defer freelist construction until after bulk allocation from a new slab
Allocations from a fresh slab can consume all of its objects, and the
freelist built during slab allocation is discarded immediately as a result.
Instead of special-casing the whole-slab bulk refill case, defer freelist
construction until after objects are emitted from a fresh slab.
new_slab() now only allocates the slab and initializes its metadata.
refill_objects() then obtains a fresh slab and lets alloc_from_new_slab()
emit objects directly, building a freelist only for the objects left
unallocated; the same change is applied to alloc_single_from_new_slab().
To keep CONFIG_SLAB_FREELIST_RANDOM=y/n on the same path, introduce a
small iterator abstraction for walking free objects in allocation order.
The iterator is used both for filling the sheaf and for building the
freelist of the remaining objects.
Also mark setup_object() inline. After this optimization, the compiler no
longer consistently inlines this helper in the hot path, which can hurt
performance. Explicitly marking it inline restores the expected code
generation.
This reduces per-object overhead when allocating from a fresh slab.
The most direct benefit is in the paths that allocate objects first and
only build a freelist for the remainder afterward: bulk allocation from
a new slab in refill_objects(), single-object allocation from a new slab
in ___slab_alloc(), and the corresponding early-boot paths that now use
the same deferred-freelist scheme. Since refill_objects() is also used to
refill sheaves, the optimization is not limited to the small set of
kmem_cache_alloc_bulk()/kmem_cache_free_bulk() users; regular allocation
workloads may benefit as well when they refill from a fresh slab.
In slub_bulk_bench, the time per object drops by about 42% to 70% with
CONFIG_SLAB_FREELIST_RANDOM=n, and by about 58% to 69% with
CONFIG_SLAB_FREELIST_RANDOM=y. This benchmark is intended to isolate the
cost removed by this change: each iteration allocates exactly
slab->objects from a fresh slab. That makes it a near best-case scenario
for deferred freelist construction, because the old path still built a
full freelist even when no objects remained, while the new path avoids
that work. Realistic workloads may see smaller end-to-end gains depending
on how often allocations reach this fresh-slab refill path.
Hyunwoo Kim [Fri, 8 May 2026 08:53:09 +0000 (17:53 +0900)]
rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present
The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE
handler in rxrpc_verify_response() copy the skb to a linear one before
calling into the security ops only when skb_cloned() is true. An skb
that is not cloned but still carries externally-owned paged fragments
(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via
__ip_append_data, or a chained skb_has_frag_list()) falls through to
the in-place decryption path, which binds the frag pages directly into
the AEAD/skcipher SGL via skb_to_sgvec().
Extend the gate to also unshare when skb_has_frag_list() or
skb_has_shared_frag() is true. This catches the splice-loopback vector
and other externally-shared frag sources while preserving the
zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC
page_pool RX, GRO). The OOM/trace handling already in place is reused.
Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()") Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 10 May 2026 15:10:47 +0000 (08:10 -0700)]
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk driver fixes from Stephen Boyd:
- Mark the DDR bus clk critical in the SpaceMiT driver so that
boot doesn't fail
- Fix boot on Mobile EyeQ by creating the auxiliary device for
the ethernet PHY
- Plug an OF node leak in Rockchip rk808 clk driver
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: rk808: fix OF node reference imbalance
MAINTAINERS: add myself as a reviewer for the clk subsystem
reset: eyeq: drop device_set_of_node_from_dev() done by parent
clk: eyeq: add EyeQ5 children auxiliary device for generic PHYs
clk: eyeq: use the auxiliary device creation helper
clk: spacemit: k3: mark top_dclk as CLK_IS_CRITICAL
Linus Torvalds [Sun, 10 May 2026 01:42:54 +0000 (18:42 -0700)]
Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Alexei Starovoitov:
- Fix sk_local_storage diag dump via netlink (Amery Hung)
- Fix off-by-one in arena direct-value access (Junyoung Jang)
- Reject TCP_NODELAY in bpf-tcp congestion control (KaFai Wan)
- Fix type confusion in bpf_*_sock() (Kuniyuki Iwashima)
- Reject TX-only AF_XDP sockets (Linpu Yu)
- Don't run arg-tracking analysis twice on main subprog (Paul Chaignon)
- Fix NULL pointer dereference in bpf_sk_storage_clone and fib lookup
(Weiming Shi)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Fix off-by-one boundary validation in arena direct-value access
xskmap: reject TX-only AF_XDP sockets
bpf: Don't run arg-tracking analysis twice on main subprog
bpf: Free reuseport cBPF prog after RCU grace period.
bpf: tcp: Fix type confusion in sol_tcp_sockopt().
bpf: tcp: Fix type confusion in bpf_skc_to_tcp6_sock().
bpf: tcp: Fix type confusion in bpf_skc_to_tcp_sock().
mptcp: bpf: Fix type confusion in bpf_mptcp_sock_from_subflow()
selftest: bpf: Add test for bpf_tcp_sock() and RAW socket.
bpf: tcp: Fix type confusion in bpf_tcp_sock().
tools/headers: Regenerate stddef.h to fix BPF selftests
bpf: Fix sk_local_storage diag dumping uninitialized special fields
bpf: Fix NULL pointer dereference in bpf_skb_fib_lookup()
sockmap: Fix sk_psock_drop() race vs sock_map_{unhash,close,destroy}().
bpf: Fix NULL pointer dereference in bpf_sk_storage_clone and diag paths
selftests/bpf: Verify bpf-tcp-cc rejects TCP_NODELAY
selftests/bpf: Test TCP_NODELAY in TCP hdr opt callbacks
bpf: Reject TCP_NODELAY in bpf-tcp-cc
bpf: Reject TCP_NODELAY in TCP header option callbacks
Junyoung Jang [Sun, 26 Apr 2026 17:25:05 +0000 (02:25 +0900)]
bpf: Fix off-by-one boundary validation in arena direct-value access
BPF_MAP_TYPE_ARENA accepts BPF_PSEUDO_MAP_VALUE offsets at exactly
the end of the arena mapping (off == arena_size). The boundary check
in arena_map_direct_value_addr() uses `>` instead of `>=`, which
incorrectly allows a one-past-end pointer to be accepted.
Change the condition to `>=` to correctly reject offsets that fall
outside the valid arena user_vm range.
Linpu Yu [Fri, 8 May 2026 14:43:43 +0000 (22:43 +0800)]
xskmap: reject TX-only AF_XDP sockets
XSKMAP entries are used as redirect targets for incoming XDP frames.
A TX-only AF_XDP socket lacks an Rx ring and cannot handle redirected
traffic, but xsk_map_update_elem() currently allows such sockets to
be inserted into the map.
Redirecting packets to such a socket on the veth generic-XDP path
causes a kernel crash in xsk_generic_rcv().
This became possible after xsk_is_setup_for_bpf_map() was removed from
the XSKMAP update path, which allowed bound TX-only sockets to be
inserted into the map.
Reject TX-only sockets during XSKMAP updates to avoid the crash.
They remain fully operational for pure Tx purposes outside XSKMAP.
Fixes: 968be23ceaca ("xsk: Fix possible segfault at xskmap entry insertion") Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Signed-off-by: Yifan Wu <yifanwucs@gmail.com> Signed-off-by: Linpu Yu <linpu5433@gmail.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://lore.kernel.org/r/20260508144344.694-1-linpu5433@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Paul Chaignon [Thu, 7 May 2026 18:22:06 +0000 (20:22 +0200)]
bpf: Don't run arg-tracking analysis twice on main subprog
Because subprog 0, the main subprog, is considered a global function,
we end up running the arg-tracking dataflow analysis twice on it. That
results in slightly longer verification but mostly in more verbose
verifier logs. This patch fixes it by keeping only the iteration over
global subprogs.
When running over all of Cilium's programs with BPF_LOG_LEVEL2, this
reduces verbosity by ~20% on average.
Linus Torvalds [Sat, 9 May 2026 18:47:39 +0000 (11:47 -0700)]
Merge tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux
Pull fsverity fix from Eric Biggers:
"Fix a regression in overlayfs caused by an fsverity API change"
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
ovl: fix verity lazy-load guard broken by fsverity_active() semantic change
Linus Torvalds [Sat, 9 May 2026 15:32:50 +0000 (08:32 -0700)]
Merge tag 'hwmon-for-v7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
- ads7871: Fix endianness bug in 16-bit register reads
- lm75: Fix configuration register writes and AS6200/TMP112 setup and
alarm handling
- lm63: Fix TOCTOU problems
- corsair-psu: Close HID device on probe errors
- ltc2992: Fix overflow and threshold range
- Documentation: fix link to ideapad-laptop.c file
- Remove stale CONFIG_SENSORS_SBRMI Makefile reference
* tag 'hwmon-for-v7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (ads7871) Fix endianness bug in 16-bit register reads
hwmon: (lm75) Fix configuration register writes.
hwmon: (lm75) Fix AS6200 and TMP112 setup and alarm handling
hwmon: (lm63) Add locking to avoid TOCTOU
hwmon: (corsair-psu) Close HID device on probe errors
hwmon: Remove stale CONFIG_SENSORS_SBRMI Makefile reference
Documentation: hwmon: fix link to ideapad-laptop.c file
hwmon: (ltc2992) Fix u32 overflow in power read path
hwmon: (ltc2992) Clamp threshold writes to hardware range
Linus Torvalds [Sat, 9 May 2026 15:10:07 +0000 (08:10 -0700)]
Merge tag 'i2c-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
- sanitize more input parameters in the core (found by syzkaller)
- usual set of driver fixes (proper completion handling, applying
quirks, correct workqueue selection...)
- ID additions to simplify dependency handling
- new email address for Peter Rosin
* tag 'i2c-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: smbus: reject oversized block transfers in the common path
MAINTAINERS: Update mail for Peter Rosin
i2c: stub: Reject I2C block transfers with invalid length
i2c: Compare the return value of gpiod_get_direction against GPIO_LINE_DIRECTION_OUT
i2c: dev: prevent integer overflow in I2C_TIMEOUT ioctl
i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids
dt-bindings: i2c: apple,i2c: Add t8122 compatible
i2c: stm32f7: reinit_completion() per transfer not per msg
dt-bindings: i2c: amlogic: Add compatible for T7 SOC
i2c: testunit: Replace system_long_wq with system_dfl_long_wq
Linus Torvalds [Sat, 9 May 2026 15:03:21 +0000 (08:03 -0700)]
Merge tag 'powerpc-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Madhavan Srinivasan:
- Fix KASAN sanitization flag for core_$(BITS).o
- Fixes for handling offset values in pseries htmdump
- Fix interrupt mask in cpm1_gpiochip_add16()
- ps3/pasemi fixes to drop redundant result assignment
- Fixes in papr-hvpipe code path
- powerpc/perf: Update check for PERF_SAMPLE_DATA_SRC marked events
Thanks to Aboorva Devarajan, Athira Rajeev, Christophe Leroy (CS GROUP),
Geert Uytterhoeven, Haren Myneni, Krzysztof Kozlowski, Mukesh Kumar
Chaurasiya (IBM), Nathan Chancellor, Ritesh Harjani (IBM), Shivani
Nittor, Sourabh Jain, Thomas Zimmermann, and Venkat Rao Bagalkote.
* tag 'powerpc-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (21 commits)
powerpc/pasemi: Drop redundant res assignment
powerpc/ps3: Drop redundant result assignment
powerpc/vdso: Drop -DCC_USING_PATCHABLE_FUNCTION_ENTRY from 32-bit flags with clang
arch/powerpc: Drop CONFIG_FIRMWARE_EDID from defconfig files
powerpc/perf: Update check for PERF_SAMPLE_DATA_SRC marked events
powerpc/8xx: Fix interrupt mask in cpm1_gpiochip_add16()
powerpc/vmx: avoid KASAN instrumentation in enter_vmx_ops() for kexec
powerpc/kdump: fix KASAN sanitization flag for core_$(BITS).o
pseries/papr-hvpipe: Fix style and checkpatch issues in enable_hvpipe_IRQ()
pseries/papr-hvpipe: Refactor and simplify hvpipe_rtas_recv_msg()
pseries/papr-hvpipe: Kill task_struct pointer from struct hvpipe_source_info
pseries/papr-hvpipe: Simplify spin unlock usage in papr_hvpipe_handle_release()
pseries/papr-hvpipe: Fix the usage of copy_to_user()
pseries/papr-hvpipe: Fix & simplify error handling in papr_hvpipe_init()
pseries/papr-hvpipe: Fix null ptr deref in papr_hvpipe_dev_create_handle()
pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace
pseries/papr-hvpipe: Fix race with interrupt handler
powerpc/pseries/htmdump: Add memory configuration dump support to htmdump module
powerpc/pseries/htmdump: Fix the offset value used in htm status dump
powerpc/pseries/htmdump: Fix the offset value used in processor configuration dump
...
Linus Torvalds [Sat, 9 May 2026 03:28:45 +0000 (20:28 -0700)]
Merge tag 'x86-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Fix memory map enumeration bug in the Xen e820 parsing code (Juergen
Gross)
- Re-enable e820 BIOS fallback if e820 table is empty (David Gow)
* tag 'x86-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/e820: Re-enable BIOS fallback if e820 table is empty
x86/xen: Fix a potential problem in xen_e820_resolve_conflicts()
Linus Torvalds [Sat, 9 May 2026 02:42:10 +0000 (19:42 -0700)]
Merge tag 'sched-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
- Fix spurious failures in rseq self-tests (Mark Brown)
- Fix rseq rseq::cpu_id_start ABI regression due to TCMalloc's creative
use of the supposedly read-only field
The fix is to introduce a new ABI variant based on a new (larger)
rseq area registration size, to keep the TCMalloc use of rseq
backwards compatible on new kernels (Thomas Gleixner)
- Fix wakeup_preempt_fair() for not waking up task (Vincent Guittot)
- Fix s64 mult overflow in vruntime_eligible() (Zhan Xusheng)
* tag 'sched-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Fix wakeup_preempt_fair() for not waking up task
sched/fair: Fix overflow in vruntime_eligible()
selftests/rseq: Expand for optimized RSEQ ABI v2
rseq: Reenable performance optimizations conditionally
rseq: Implement read only ABI enforcement for optimized RSEQ V2 mode
selftests/rseq: Validate legacy behavior
selftests/rseq: Make registration flexible for legacy and optimized mode
selftests/rseq: Skip tests if time slice extensions are not available
rseq: Revert to historical performance killing behaviour
rseq: Don't advertise time slice extensions if disabled
rseq: Protect rseq_reset() against interrupts
rseq: Set rseq::cpu_id_start to 0 on unregistration
selftests/rseq: Don't run tests with runner scripts outside of the scripts
Linus Torvalds [Sat, 9 May 2026 02:39:18 +0000 (19:39 -0700)]
Merge tag 'perf-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events fixes from Ingo Molnar:
- Fix deadlock in the perf_mmap() failure path (Peter Zijlstra)
- Intel ACR (Auto Counter Reload) fixes (Dapeng Mi):
- Fix validation and configuration of ACR masks
- Fix ACR rescheduling bug causing stale masks
- Disable the PMI on ACR-enabled hardware
- Enable ACR on Panther Cover uarch too
* tag 'perf-urgent-2026-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Enable auto counter reload for DMR
perf/x86/intel: Disable PMI for self-reloaded ACR events
perf/x86/intel: Always reprogram ACR events to prevent stale masks
perf/x86/intel: Improve validation and configuration of ACR masks
perf/core: Fix deadlock in perf_mmap() failure path
Linus Torvalds [Fri, 8 May 2026 23:08:58 +0000 (16:08 -0700)]
Merge tag 'pci-v7.1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI fixes from Bjorn Helgaas:
- Don't fallback to bus reset after failed slot reset; a bus reset
isn't safe if the .reset_slot() callback is implemented (Keith Busch)
- Update saved_config_space upon resource assignment to fix passthrough
regressions when x86 pcibios_assign_resources() updates BARs (Lukas
Wunner)
- Initialize a temporary pci_dev->dev in sysfs 'new_id' attribute to
fix a lockdep regression after driver_override was moved from PCI to
device core (Samiullah Khawaja)
- Update MAINTAINERS email addresses (Marek Vasut, Hans Zhang)
- Add MAINTAINERS reviewer for PCIe Cadence IP (Aksh Garg)
* tag 'pci-v7.1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
MAINTAINERS: Add Aksh Garg as PCIe CADENCE reviewer
MAINTAINERS: Update Hans Zhang email for PCIe CIX Sky1
MAINTAINERS: Update Marek Vasut email for PCIe R-Car
PCI: Initialize temporary device in new_id_store()
PCI: Update saved_config_space upon resource assignment
PCI: Don't fallback to bus reset after failed slot reset
PCI: Initialize temporary device in new_id_store()
When setting new_id of a PCI device driver using sysfs a lockdep splat
occurs. This is because new_id_store() builds a temporary pci_dev for
pci_match_device(), which calls device_match_driver_override(). That
depends on the driver_override.lock added by cb3d1049f4ea ("driver core:
generalize driver_override in struct device").
The new driver_override.lock was not initialized in the temporary pci_dev,
resulting in this lockdep splat.
Initialize the temporary pci_dev to fix this.
Repro:
Build with CONFIG_LOCKDEP=y, boot with QEMU, and add a new ID:
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 2 UID: 0 PID: 177 Comm: liveupdate-iomm Not tainted 7.0.0+ #9 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
register_lock_class+0x77e/0x790
lock_acquire+0xbf/0x2e0
pci_match_device+0x24/0x180
new_id_store+0x189/0x1d0
kernfs_fop_write_iter+0x14f/0x210
vfs_write+0x263/0x5e0
ksys_write+0x79/0xf0
do_syscall_64+0x117/0xf80
Fixes: 10a4206a2401 ("PCI: use generic driver_override infrastructure") Fixes: 8895d3bcb8ba ("PCI: Fail new_id for vendor/device values already built into driver") Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
[bhelgaas: add commit log details and repro, trim backtrace] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Danilo Krummrich <dakr@kernel.org> Link: https://patch.msgid.link/20260505234327.716630-1-skhawaja@google.com
PCI: Update saved_config_space upon resource assignment
Bernd reports passthrough failure of a Digital Devices Cine S2 V6 DVB
adapter plugged into an ASRock X570S PG Riptide board with BIOS version
P5.41 (09/07/2023):
ddbridge 0000:05:00.0: detected Digital Devices Cine S2 V6 DVB adapter
ddbridge 0000:05:00.0: cannot read registers
ddbridge 0000:05:00.0: fail
BIOS assigns an incorrect BAR to the DVB adapter which doesn't fit into the
upstream bridge window. The kernel corrects the BAR assignment:
pci 0000:07:00.0: BAR 0 [mem 0xfffffffffc500000-0xfffffffffc50ffff 64bit]: can't claim; no compatible bridge window
pci 0000:07:00.0: BAR 0 [mem 0xfc500000-0xfc50ffff 64bit]: assigned
Correction of the BAR assignment happens in an x86-specific fs_initcall,
pcibios_assign_resources(), after device enumeration in a subsys_initcall.
This order was introduced at the behest of Linus in 2004:
No other architecture performs such a late BAR correction.
Bernd bisected the issue to commit a2f1e22390ac ("PCI/ERR: Ensure error
recoverability at all times"), but it only occurs in the absence of commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing").
This combination exists in stable kernel v6.12.70, but not in mainline,
hence Bernd cannot reproduce the issue with mainline.
Since a2f1e22390ac, config space is saved on enumeration, prior to BAR
correction. Upon passthrough, the corrected BAR is overwritten with the
incorrect saved value by:
But only if the device's current_state is PCI_UNKNOWN, as it was prior to
commit 4d4c10f763d7. Since the commit, it is PCI_D0, which changes the
behavior of vfio_pci_set_power_state() to no longer restore the state
without saving it first.
Alexandre is reporting the same issue as Bernd, but in his case, mainline
is affected as well. The difference is that on Alexandre's system, the
host kernel binds a driver to the device which is unbound prior to
passthrough, whereas on Bernd's system no driver gets bound by the host
kernel.
Unbinding sets current_state to PCI_UNKNOWN in pci_device_remove(), so when
vfio-pci is subsequently bound to the device, pci_restore_state() is once
again called without invoking pci_save_state() first.
To robustly fix the issue, always update saved_config_space upon resource
assignment.
Reported-by: Bernd Schumacher <bernd@bschu.de> Closes: https://lore.kernel.org/r/acfZrlP0Ua_5D3U4@eldamar.lan/ Reported-by: Alexandre N. <an.tech@mailo.com> Closes: https://lore.kernel.org/r/dd3c3358-de0f-4a56-9c81-04aceaab4058@mailo.com/ Fixes: a2f1e22390ac ("PCI/ERR: Ensure error recoverability at all times") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Bernd Schumacher <bernd@bschu.de> Tested-by: Alexandre N. <an.tech@mailo.com> Cc: stable@vger.kernel.org # v6.12+ Link: https://patch.msgid.link/febc3f354e0c1f5a9f5b3ee9ffddaa44caccf651.1776268054.git.lukas@wunner.de
bpf: Free reuseport cBPF prog after RCU grace period.
Eulgyu Kim reported the splat below with a repro. [0]
The repro sets up a UDP reuseport group with a cBPF prog and
replaces it with a new one while another thread is sending
a UDP packet to the group.
The reuseport prog is freed by sk_reuseport_prog_free().
bpf_prog_put() is called for "e"BPF prog to destruct through
multiple stages while cBPF prog is freed immediately by
bpf_release_orig_filter() and bpf_prog_free().
If a reuseport prog is detached from the setsockopt() path
(reuseport_attach_prog() or reuseport_detach_prog()),
sk_reuseport_prog_free() is called without waiting for RCU
readers to complete, resulting in various bugs.
Let's defer freeing the reuseport cBPF prog after one RCU
grace period.
Note "e"BPF prog is safe as is unless the fast path starts
to touch fields destroyed in bpf_prog_put_deferred() and
__bpf_prog_put_noref().
Linus Torvalds [Fri, 8 May 2026 20:18:13 +0000 (13:18 -0700)]
Merge tag 'block-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block fixes from Jens Axboe:
- Fix for ublk not doing an actual issue from the task_work fallback
path. Any request hitting that should be canceled automatically
- Fix for uring_cmd prep side handling, for the block side uring_cmd
discard handling
- Fix for missing validation of the io and physical block size shifts
- Fix for a use-after-free in ublk's cancel command handling
* tag 'block-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
ublk: fix use-after-free in ublk_cancel_cmd()
ublk: validate physical_bs_shift, io_min_shift and io_opt_shift
block: only read from sqe on initial invocation of blkdev_uring_cmd()
ublk: don't issue uring_cmd from fallback task work
Linus Torvalds [Fri, 8 May 2026 20:12:48 +0000 (13:12 -0700)]
Merge tag 'io_uring-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring fixes from Jens Axboe:
- Ensure that the absolute timeouts for both the command side and the
waiting side honor the callers time namespace
- Ensure tracked NAPI entries are cleared at unregistration time, as
the NAPI polling loop checks the list state rather than the general
NAPI state. This can lead to NAPI polling even after unregistration
has been done. If unregistered, all NAPI polling should be disabled
- Fix for eventfd recursive invocation handling
* tag 'io_uring-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring/wait: honour caller's time namespace for IORING_ENTER_ABS_TIMER
io_uring/timeout: honour caller's time namespace for IORING_TIMEOUT_ABS
io_uring/eventfd: reset deferred signal state
io_uring/napi: clear tracked NAPI entries on unregister
bpf: tcp: Fix type confusion in sol_tcp_sockopt().
sol_tcp_sockopt() only checks if sk->sk_protocol is IPPROTO_TCP,
but RAW socket can bypass it:
socket(AF_INET, SOCK_RAW, IPPROTO_TCP)
Let's use sk_is_tcp().
Note that initially sol_tcp_sockopt() checked sk->sk_prot->setsockopt.
Fixes: 2ab42c7b871f ("bpf: Check the protocol of a sock to agree the calls to bpf_setsockopt().") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20260504210610.180150-7-kuniyu@google.com
mptcp: bpf: Fix type confusion in bpf_mptcp_sock_from_subflow()
bpf_mptcp_sock_from_subflow() only checks if sk->sk_protocol is
IPPROTO_TCP, but RAW socket can bypass it:
socket(AF_INET, SOCK_RAW, IPPROTO_TCP)
In this case, it would NOT be valid to call sk_is_mptcp() which will
assume sk is a pointer to a struct tcp_sock, and wrongly checks for:
tcp_sk(sk)->is_mptcp.
Linus Torvalds [Fri, 8 May 2026 17:24:35 +0000 (10:24 -0700)]
Merge tag 'v7.1-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fixes from Steve French:
- Fix for two ACL issues (security fix to validate dacloffset better
and chmod fix)
- Fix out of bounds reads (in check_wsl_eas and smb2_check_msg for
symlinks)
- Two Kerberos fixes including an important one when AES-256 encryption
chosen
- Fix open_cached_dir problem when directory leases disabled
* tag 'v7.1-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb: client: validate dacloffset before building DACL pointers
smb/client: fix out-of-bounds read in smb2_compound_op()
smb/client: fix out-of-bounds read in symlink_data()
smb: client: Zero-pad short GSS session keys per MS-SMB2
smb: client: Use FullSessionKey for AES-256 encryption key derivation
smb: client: use kzalloc to zero-initialize security descriptor buffer
cifs: abort open_cached_dir if we don't request leases
Linus Torvalds [Fri, 8 May 2026 17:14:51 +0000 (10:14 -0700)]
Merge tag 'spi-fix-v7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"There's two main series here, fixing issues that came up in the
Microchip QSPI and Freescale i.MX drivers. Both of those could result
in some quite noticable issues if they were encountered in production.
We also have one minor documentation fix in the ch341 driver"
* tag 'spi-fix-v7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: ch341: correct company name in MODULE_DESCRIPTION
spi: microchip-core-qspi: remove some inline markings
spi: microchip-core-qspi: don't attempt to transmit during emulated read-only dual/quad operations
spi: microchip-core-qspi: control built-in cs manually
spi: imx: Propagate prepare_transfer() error from spi_imx_setupxfer()
spi: imx: Fix UAF on package-1 prepare failure in spi_imx_dma_data_prepare()
spi: imx: Fix precedence bug in spi_imx_dma_max_wml_find()
The buggy address belongs to the object at ffff88801083d280
which belongs to the cache RAW of size 1792
The buggy address is located 1248 bytes inside of
allocated 1792-byte region [ffff88801083d280, ffff88801083d980)
Fixes: 655a51e536c0 ("bpf: Add struct bpf_tcp_sock and BPF_FUNC_tcp_sock") Reported-by: Damiano Melotti <melotti@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/20260504210610.180150-2-kuniyu@google.com
Linus Torvalds [Fri, 8 May 2026 15:23:06 +0000 (08:23 -0700)]
Merge tag 'drm-fixes-2026-05-08-1' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie:
"Weekly fixes, lots of them but all pretty small, amdgpu and xe are the
usual but then a large amount of fixes all over.
xe:
- Add NULL check for media_gt in intel_hdcp_gsc_check_status
- Fix EAGAIN sign in pf_migration_consume
- Fix MMIO access using PF view instead of VF view during migration
- Exclude indirect ring state page from ADS engine state size
* tag 'drm-fixes-2026-05-08-1' of https://gitlab.freedesktop.org/drm/kernel: (37 commits)
drm: Set old handle to NULL before prime swap in change_handle
drm/bochs: Drop manual put on probe error path
drm/xe/guc: Exclude indirect ring state page from ADS engine state size
drm/xe/pf: Fix MMIO access using PF view instead of VF view during migration
drm/xe/pf: Fix EAGAIN sign in pf_migration_consume()
drm/xe/hdcp: Add NULL check for media_gt in intel_hdcp_gsc_check_status()
drm/exynos: remove bridge when component_add fails
drm/amdgpu: nuke amdgpu_userq_fence_slab v2
drm/amdgpu/userq: fix access to stale wptr mapping
drm/amdkfd: Check if there are kfd porcesses using adev by kfd_processes_count
drm/amdgpu: zero-initialize GART table on allocation
drm/amdgpu/sdma4: replace BUG_ON with WARN_ON in fence emission
drm/radeon: add missing revision check for CI
drm/amdgpu/pm: align Hawaii mclk workaround with radeon
drm/amdgpu/pm: add missing revision check for CI
drm/amdgpu/gfx9: drop unnecessary 64-bit fence flag check in KIQ
drm/amdkfd: Make all TLB-flushes heavy-weight
drm/panel: himax-hx83102: restore MODE_LPM after sending disable cmds
drm/panel: boe-tv101wum-nl6: restore MODE_LPM after sending disable cmds
drm/panel: feiyang-fy07024di26a30d: return display-on error
...
Linus Torvalds [Fri, 8 May 2026 15:16:07 +0000 (08:16 -0700)]
Merge tag 'iommu-fixes-v7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux
Pull iommu fixes from Joerg Roedel:
"Core:
- Cache-flushing fix for non-x86 platforms
AMD-Vi:
- Security fix when SEV-SNP is enabled
- Operator precedence fix in DTE setting"
* tag 'iommu-fixes-v7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux:
iommu/amd: Fix precedence order in set_dte_passthrough()
iommu/pages: Fix iommu_pages_flush_incoherent() for non-x86
iommu/amd: Use maximum PPR log buffer size when SNP is enabled on Family 0x19
iommu/amd: Use maximum Event log buffer size when SNP is enabled on Family 0x19
Ming Lei [Fri, 8 May 2026 12:37:46 +0000 (20:37 +0800)]
ublk: fix use-after-free in ublk_cancel_cmd()
When ublk_reset_ch_dev() clears io->cmd via ublk_queue_reinit()
concurrently with ublk_cancel_cmd(), ublk_cancel_cmd() can read a
stale pointer and pass it to io_uring_cmd_done(), causing a
use-after-free.
Fix by synchronizing the two paths with ubq->cancel_lock:
- ublk_cancel_cmd(): read and clear io->cmd under cancel_lock,
then call io_uring_cmd_done() on the saved local copy outside
the lock.
- ublk_reset_ch_dev(): hold cancel_lock across ublk_queue_reinit()
so that io->cmd and io->flags are cleared atomically with respect
to ublk_cancel_cmd().
Francis, David [Tue, 28 Apr 2026 19:25:50 +0000 (19:25 +0000)]
drm: Set old handle to NULL before prime swap in change_handle
There was a potential race condition in change_handle. The ioctl
briefly had a single object with two idr entries; a concurrent
gem_close could delete the object and remove one of the handles
while leaving the other one dangling, which could subsequently
be dereferenced for a use-after-free.
To fix this, do the same dance that gem_close itself does.
(f6cd7daecff5 drm: Release driver references to handle before making it available again)
First idr_replace the old handle to NULL. Later, if the prime
operations are successful, actually close it.
create_tail required a similar dance to avoid a similar problem.
(bd46cece51a3 drm/gem: Fix race in drm_gem_handle_create_tail())
It idr_allocs the new handle with NULL, then swaps in the correct
object later to avoid races. We don't need to do that here, since
the only operations that could race are drm_prime, and
change_handle holds the prime lock for the entire duration.
v2: cleanups of error paths
Signed-off-by: David Francis <David.Francis@amd.com> Co-authored-by: Dave Airlie <airlied@gmail.com> Reported-by: Puttimet Thammasaeng <pwn8official@gmail.com> Tested-by: Vitaly Prosyak <Vitaly.Prosyak@amd.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: stable@vger.kernel.org Cc: Christian Koenig <Christian.Koenig@amd.com> Fixes: 53096728b8910 ("drm: Add DRM prime interface to reassign GEM handle") Signed-off-by: Dave Airlie <airlied@redhat.com>
Linus Torvalds [Fri, 8 May 2026 00:26:43 +0000 (17:26 -0700)]
Merge tag 'selinux-pr-20260507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux fixes from Paul Moore:
- Allow for multiple opens of /sys/fs/selinux/policy
Prevent a single process from blocking others from reading the
SELinux policy loaded in the kernel. This does have the side effect
of potentially allowing userspace to trigger additional kernel memory
allocations as part of the open/read operation, but this is mitigated
by requiring the SELinux security/read_policy permission.
- Reduce the critical sections where the SELinux policy mutex is held
This includes the patch to the policy loader code where we move the
permission checks and an allocation outside the mutex as well as the
the patch to checkreqprot which drops the code/lock entirely.
While the checkreqprot code had effectively been dropped in an
earlier release, portions of the code still remained that would have
triggered the mutex to perform an IMA measurement. This finally drops
all of that while preserving the user visible behavior.
- Eliminate potential sources of log spamming
There were a few areas where processes could flood the system logs
and hide other, more critical events. The previously disabled
checkreqprot and runtime disable knobs in selinuxfs were two such
areas that have now been greatly simplified and a pr_err() replaced
with a pr_err_once().
The third such place is the /sys/fs/selinux/user file, which hasn't
been used by a userspace release since 2020 and was scheduled for
removal after 2025; this effectively disables this functionality, but
similar to checkreqprot, it is done in a way that should not break
old userspace.
* tag 'selinux-pr-20260507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: shrink critical section in sel_write_load()
selinux: allow multiple opens of /sys/fs/selinux/policy
selinux: prune /sys/fs/selinux/user
selinux: prune /sys/fs/selinux/disable
selinux: prune /sys/fs/selinux/checkreqprot
Tabrez Ahmed [Sat, 2 May 2026 02:08:42 +0000 (07:38 +0530)]
hwmon: (ads7871) Fix endianness bug in 16-bit register reads
The ads7871_read_reg16() function relies on spi_w8r16() to read the
16-bit sensor output. The ADS7871 device transmits the Least Significant
Byte (LSB) first.
On Little-Endian architectures, spi_w8r16() correctly reconstructs the
16-bit value. However, on Big-Endian architectures, the byte swapping
causes the first received byte (LSB) to be placed in the most significant
byte of the u16, resulting in corrupted voltage readings.
To fix this, cast the integer result of spi_w8r16() to a restricted
__le16 type and convert it to the host CPU's native byte order using
le16_to_cpu(). Negative error codes returned by the SPI core are caught
and returned prior to the conversion to avoid mangling the error status.
Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260418034601.90226-1-tabreztalks@gmail.com Fixes: e0c70b8078629 ("hwmon: add TI ads7871 a/d converter driver") Suggested-by: David Laight <david.laight.linux@gmail.com> Signed-off-by: Tabrez Ahmed <tabreztalks@gmail.com> Link: https://lore.kernel.org/r/20260502020844.110038-2-tabreztalks@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Sensors configurations are defined by set and clear masks. These
do not follow a consistent "clear mask is a superset of set mask"
rule. This relaxed definition breaks lm75_write_config()
Basically all bits from set_mask that are not defined in clr_mask are
dropped. Fix that by enhancing the helper to always combine clr_mask
and set_mask into the mask bits of regmap_update_bits().
hwmon: (lm75) Fix AS6200 and TMP112 setup and alarm handling
The initialization of the AS6200 has two shortcomings
- The device-add-commit states "Conversion mode: continuous" but the
the lm75_params structure uses set_mask = 0x94c0. This activates
single shot mode (bit 15). According to the datasheet "The device
features a single shot measurement mode if the device is in sleep
mode (SM=1)". This is quite contradictionary.
- It is the only device that activates polarity active-high (bit 10)
All this is paired with a undefined clear mask bug in function
lm75_write_config() that was introduced with a later refactoring
commit.
[as6200] = {
.config_reg_16bits = true,
.set_mask = 0x94C0,
-> .clr_mask not defined here
.default_resolution = 12,
...
static inline int lm75_write_config(struct lm75_data *data, u16 set_mask,
u16 clr_mask)
{
return regmap_update_bits(data->regmap, LM75_REG_CONF,
clr_mask | LM75_SHUTDOWN, set_mask);
}
regmap_update_bits() requires clr_mask to be a superset of set_mask.
So basically all sensors with "wrong" masks like the AS6200 are not
initialized as intended.
Fix that by
- Change the set_mask to 0xc010 to reflect the current active-low
setup properly and to drive the sensor in continous mode. This
takes into account that the config register is little endian and
the first byte sent to the chip is the LSB.
- Adapt the alarm handling so it can report the alarm correctly
even if it is high active. This is done by comparing config register
bit 5 and 10 (translated to 2 and 13).
This commit does not introduce any ABI breakage as the mutliple bugs
effectly drive the AS6200 in standard active-low mode.
Fixes: 4b6358e1fe46 ("hwmon: (lm75) Add AMS AS6200 temperature sensor") Suggested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de> Link: https://lore.kernel.org/r/20260502173207.3567876-2-markus.stockhausen@gmx.de
[groeck: Update set_mask for as6200 further: As modeled, the upper bits
contain the conversion rate, so the config register needs to be set to
0xc010 instead of 0x10c0 to reflect 8 samples/s and 4 consecutive faults.
Fix the same problem for TMP112.] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Dave Airlie [Thu, 7 May 2026 22:51:01 +0000 (08:51 +1000)]
Merge tag 'drm-xe-fixes-2026-05-07' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes
UAPI Changes:
Cross-subsystem Changes:
Core Changes:
Driver Changes:
- Add NULL check for media_gt in intel_hdcp_gsc_check_status (Gustavo)
- Fix EAGAIN sign in pf_migration_consume (Shuicheng)
- Fix MMIO access using PF view instead of VF view during migration (Shuicheng)
- Exclude indirect ring state page from ADS engine state size (Satya)
Dave Airlie [Thu, 7 May 2026 22:34:34 +0000 (08:34 +1000)]
Merge tag 'drm-rust-fixes-2026-05-07' of https://gitlab.freedesktop.org/drm/rust/kernel into drm-fixes
DRM Rust fixes for v7.1-rc3
- Fix unsound initialization in drm::Device::new(); if pinned
initialization of drm::Device::Data fails, make sure
drm::Device::release() isn't called, so we don't run the data's
destructor
- Fix missing GEM state cleanup in the init failure case; call
drm_gem_private_object_fini() if drm_gem_object_init() fails
- Fix wrong ARef import in the DRM shmem GEM helper abstraction
- Replace the nouveau mailing list with the new nova-gpu mailing list
for both nova-core and nova-drm, and remove unused patchwork entries
smb: client: validate dacloffset before building DACL pointers
parse_sec_desc(), build_sec_desc(), and the chown path in
id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd
before proving a DACL header fits inside the returned security
descriptor.
On 32-bit builds a malicious server can return dacloffset near
U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip
past the later pointer-based bounds checks. build_sec_desc() and
id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped
pointer in the chmod/chown rewrite paths.
Validate dacloffset numerically before building any DACL pointer and
reuse the same helper at the three DACL entry points.
Fixes: bc3e9dd9d104 ("cifs: Change SIDs in ACEs while transferring file ownership.") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Zisen Ye [Wed, 6 May 2026 03:49:08 +0000 (11:49 +0800)]
smb/client: fix out-of-bounds read in smb2_compound_op()
If a server sends a truncated response but a large OutputBufferLength, and
terminates the EA list early, check_wsl_eas() returns success without
validating that the entire OutputBufferLength fits within iov_len.
Then smb2_compound_op() does:
memcpy(idata->wsl.eas, data[0], size[0]);
Where size[0] is OutputBufferLength. If iov_len is smaller than size[0],
memcpy can read beyond the end of the rsp_iov allocation and leak adjacent
kernel heap memory.
Zisen Ye [Sat, 2 May 2026 10:48:36 +0000 (18:48 +0800)]
smb/client: fix out-of-bounds read in symlink_data()
Since smb2_check_message() returns success without length validation for
the symlink error response, in symlink_data() it is possible for
iov->iov_len to be smaller than sizeof(struct smb2_err_rsp). If the buffer
only contains the base SMB2 header (64 bytes), accessing
err->ErrorContextCount (at offset 66) or err->ByteCount later in
symlink_data() will cause an out-of-bounds read.
Piyush Sachdeva [Thu, 7 May 2026 16:52:14 +0000 (22:22 +0530)]
smb: client: Zero-pad short GSS session keys per MS-SMB2
Per MS-SMB2 section 3.2.5.3, Session.SessionKey is the first 16 bytes
of the GSS cryptographic key, right-padded with zero bytes if the key
is shorter than 16 bytes.
SMB2_auth_kerberos() copies the GSS session key from the cifs.upcall
response using kmemdup(msg->data, msg->sesskey_len, ...) and stores
the GSS-reported length verbatim in ses->auth_key.len. generate_key()
reads SMB2_NTLMV2_SESSKEY_SIZE bytes from this buffer when feeding the
HMAC-SHA256 KDF for signing key derivation. If a GSS mechanism returns
a session key shorter than 16 bytes (e.g. a deprecated single-DES
Kerberos enctype with an 8-byte session key), the KDF call performs an
out-of-bounds slab read and derives keys that do not match the server,
which pads per the spec.
Modern KDCs disable short-key enctypes by default, so this is latent
rather than reachable in production, but it is still a kernel heap
over-read.
Allocate auth_key.response with kzalloc() at a length of
max(msg->sesskey_len, SMB2_NTLMV2_SESSKEY_SIZE), copy the GSS key in,
and rely on kzalloc()'s zero initialization for the spec-mandated
padding. Set ses->auth_key.len to the padded length. Larger GSS keys
(e.g. the 32-byte aes256-cts-hmac-sha1-96 session key) continue to be
stored at their natural length, preserving the FullSessionKey path.
Emit a cifs_dbg(VFS, ...) message when a short key is encountered to
surface deprecated-enctype usage.
NTLMv2 and NTLMSSP code paths produce a 16-byte session key by
construction and are unaffected.
Signed-off-by: Piyush Sachdeva <psachdeva@microsoft.com> Signed-off-by: Piyush Sachdeva <s.piyush1024@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Piyush Sachdeva [Thu, 7 May 2026 16:52:13 +0000 (22:22 +0530)]
smb: client: Use FullSessionKey for AES-256 encryption key derivation
When Kerberos authentication is used with AES-256 encryption (AES-256-CCM
or AES-256-GCM), the SMB3 encryption and decryption keys must be derived
using the full session key (Session.FullSessionKey) rather than just the
first 16 bytes (Session.SessionKey).
Per MS-SMB2 section 3.2.5.3.1, when Connection.Dialect is "3.1.1" and
Connection.CipherId is AES-256-CCM or AES-256-GCM, Session.FullSessionKey
must be set to the full cryptographic key from the GSS authentication
context. The encryption and decryption key derivation (SMBC2SCipherKey,
SMBS2CCipherKey) must use this FullSessionKey as the KDF input. The
signing key derivation continues to use Session.SessionKey (first 16
bytes) in all cases.
Previously, generate_key() hardcoded SMB2_NTLMV2_SESSKEY_SIZE (16) as the
HMAC-SHA256 key input length for all derivations. When Kerberos with
AES-256 provides a 32-byte session key, the KDF for encryption/decryption
was using only the first 16 bytes, producing keys that did not match the
server's, causing mount failures with sec=krb5 and require_gcm_256=1.
Add a full_key_size parameter to generate_key() and pass the appropriate
size from generate_smb3signingkey():
- Signing: always SMB2_NTLMV2_SESSKEY_SIZE (16 bytes)
- Encryption/Decryption: ses->auth_key.len when AES-256, otherwise 16
Also fix cifs_dump_full_key() to report the actual session key length for
AES-256 instead of hardcoded CIFS_SESS_KEY_SIZE, so that userspace tools
like Wireshark receive the correct key for decryption.
Cc: <stable@vger.kernel.org> Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Piyush Sachdeva <psachdeva@microsoft.com> Signed-off-by: Piyush Sachdeva <s.piyush1024@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Daniel Machon [Wed, 6 May 2026 07:25:39 +0000 (09:25 +0200)]
net: sparx5: configure serdes for 1000BASE-X in sparx5_port_init()
sparx5_port_init() only invokes sparx5_serdes_set() and the associated
shadow-device enable and low-speed device switch for SGMII and QSGMII.
On any port with a high-speed primary device (DEV5G/DEV10G/DEV25G)
configured for 1000BASE-X the serdes is therefore left uninitialized,
the DEV2G5 shadow is never enabled, and the port stays pointed at its
high-speed device rather than the DEV2G5. The PCS1G block looks
healthy in isolation, but no frames reach the link partner.
Add 1000BASE-X to the check so the same three steps run.
Note: the same issue might apply to 2500BASE-X, but that will,
eventually, be addressed in a separate commit.
The value read back from the chip is GCB_CHIP_ID_PART_ID, which is a
GENMASK(27, 12) field, i.e. at most 16 bits wide. It can never match
these IDs, so probing a TSN part fails with a "Target not supported"
error.
Fix the enum to use the actual 16-bit part IDs returned by the
hardware: 0x0546, 0x0549, 0x0552, 0x0556 and 0x0558.
projects / linux / log