netfilter: ipset: Fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP

[ Upstream commit 7433b6d2afd512d04398c73aa984d1e285be125b ]

Kyle Zeng reported that there is a race between IPSET_CMD_ADD and IPSET_CMD_SWAP
in netfilter/ip_set, which can lead to the invocation of `__ip_set_put` on a
wrong `set`, triggering the `BUG_ON(set->ref == 0);` check in it.

The race is caused by using the wrong reference counter, i.e. the ref counter instead
of ref_netlink.

BUG=b/303207619
TEST=presubmit
RELEASE_NOTE=Fix CVE-2023-42756 in COS kernel.

cos-patch: security-moderate
Fixes: 24e227896bbf ("netfilter: ipset: Add schedule point in call_ad().")
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Closes: https://lore.kernel.org/netfilter-devel/ZPZqetxOmH+w%2Fmyc@westworld/#r
Tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Change-Id: I257422d17691b18f5609740fa38cd1f74f7a0244
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Nandhini Rengaraj <nrengaraj@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/58876
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
1 file changed