From: Sabrina Dubroca Date: Tue, 1 Oct 2024 16:48:14 +0000 (+0200) Subject: xfrm: validate new SA's prefixlen using SA family when sel.family is unset X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8df5cd51fd70c33aa1776e5cbcd82b0a86649d73;p=linux xfrm: validate new SA's prefixlen using SA family when sel.family is unset [ Upstream commit 3f0ab59e6537c6a8f9e1b355b48f9c05a76e8563 ] This expands the validation introduced in commit 07bf7908950a ("xfrm: Validate address prefix lengths in the xfrm selector.") syzbot created an SA with usersa.sel.family = AF_UNSPEC usersa.sel.prefixlen_s = 128 usersa.family = AF_INET Because of the AF_UNSPEC selector, verify_newsa_info doesn't put limits on prefixlen_{s,d}. But then copy_from_user_state sets x->sel.family to usersa.family (AF_INET). Do the same conversion in verify_newsa_info before validating prefixlen_{s,d}, since that's how prefixlen is going to be used later on. Reported-by: syzbot+cc39f136925517aed571@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert Signed-off-by: Antony Antony Signed-off-by: Sasha Levin --- diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 070946d09381..e28e49499713 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -149,6 +149,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p, struct nlattr **attrs) { int err; + u16 family = p->sel.family; err = -EINVAL; switch (p->family) { @@ -167,7 +168,10 @@ static int verify_newsa_info(struct xfrm_usersa_info *p, goto out; } - switch (p->sel.family) { + if (!family && !(p->flags & XFRM_STATE_AF_UNSPEC)) + family = p->family; + + switch (family) { case AF_UNSPEC: break;