]> git.hungrycats.org Git - linux/commit
tipc: fix uninit skb->data in tipc_nl_compat_dumpit()
authorCong Wang <xiyou.wangcong@gmail.com>
Sat, 15 Aug 2020 23:29:15 +0000 (16:29 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Aug 2020 07:30:49 +0000 (09:30 +0200)
commit31ee37fc7fb6a5b0bc6a752c048486cb40eebf47
tree3cd3cde7ff5acf117df8d928a2ef6d0242af9d54
parent8e6165e8e3bde6869f2711b326316b8e769ac721
tipc: fix uninit skb->data in tipc_nl_compat_dumpit()

[ Upstream commit 47733f9daf4fe4f7e0eb9e273f21ad3a19130487 ]

__tipc_nl_compat_dumpit() has two callers, and it expects them to
pass a valid nlmsghdr via arg->data. This header is artificial and
crafted just for __tipc_nl_compat_dumpit().

tipc_nl_compat_publ_dump() does so by putting a genlmsghdr as well
as some nested attribute, TIPC_NLA_SOCK. But the other caller
tipc_nl_compat_dumpit() does not, this leaves arg->data uninitialized
on this call path.

Fix this by just adding a similar nlmsghdr without any payload in
tipc_nl_compat_dumpit().

This bug exists since day 1, but the recent commit 6ea67769ff33
("net: tipc: prepare attrs in __tipc_nl_compat_dumpit()") makes it
easier to appear.

Reported-and-tested-by: syzbot+0e7181deafa7e0b79923@syzkaller.appspotmail.com
Fixes: d0796d1ef63d ("tipc: convert legacy nl bearer dump to nl compat")
Cc: Jon Maloy <jmaloy@redhat.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/tipc/netlink_compat.c