tree 0765e74a79aa164d5a74a768dc7c9998f2f3bee2
parent 77b311e7e8d726c86113f754defcd58d09b9aa17
author Florian Westphal <fw@strlen.de> 1752838033 +0200
committer Robert Kolchmeyer <rkolchmeyer@google.com> 1757557082 -0700

netfilter: xt_nfacct: don't assume acct name is null-terminated

[ Upstream commit bf58e667af7d96c8eb9411f926a0a0955f41ce21 ]

BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721
Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851
[..]
 string+0x231/0x2b0 lib/vsprintf.c:721
 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874
 [..]
 nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41
 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523

nfnl_acct_find_get() handles non-null input, but the error
printk relied on its presence.

BUG=b/440735383
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2025-38639 in the Linux kernel.

cos-patch: security-moderate
Reported-by: syzbot+4ff165b9251e4d295690@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4ff165b9251e4d295690
Tested-by: syzbot+4ff165b9251e4d295690@syzkaller.appspotmail.com
Fixes: ceb98d03eac5 ("netfilter: xtables: add nfacct match to support extended accounting")
Change-Id: I23798908377e57b2a6ef37af0537d69f45253d88
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/111121
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Chenglong Tang <chenglongtang@google.com>