tree 1d59b826c8ff1c64aaeb59c63a3e7caae4e8a90b
parent 22c71258c7655561e7edfb0852136a27c9b274d7
author Kyle Zeng <zengyhkyle@gmail.com> 1694754777 -0700
committer Anil Altinay <aaltinay@google.com> 1698982375 +0000

ipv4: fix null-deref in ipv4_link_failure

[ Upstream commit 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c ]

Currently, we assume the skb is associated with a device before calling
__ip_options_compile, which is not always the case if it is re-routed by
ipvs.
When skb->dev is NULL, dev_net(skb->dev) will become null-dereference.
This patch adds a check for the edge case and switch to use the net_device
from the rtable when skb->dev is NULL.

BUG=b/304963320
TEST=presubmit
RELEASE_NOTE=Fixes CVE-2023-42754 in the Linux kernel.

Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure")
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Cc: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Change-Id: I4e5ce72fe9ace70cbf17293927eff76f8ad9ad63
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/60619
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>