tree c51c45ff56a763fc142e400d5479c7b6f048b4b2
parent 6a85c2f90957fb25fb22bd729fb5919aca06a8d3
author Pablo Neira Ayuso <pablo@netfilter.org> 1694067753 +0200
committer COS Cherry Picker <cloud-image-release@prod.google.com> 1696547503 -0700

netfilter: nf_tables: disallow rule removal from chain binding

[ Upstream commit f15f29fd4779be8a418b66e9d52979bb6d6c2325 ]

Chain binding only requires the rule addition/insertion command within
the same transaction. Removal of rules from chain bindings within the
same transaction makes no sense, userspace does not utilize this
feature. Replace nft_chain_is_bound() check to nft_chain_binding() in
rule deletion commands. Replace command implies a rule deletion, reject
this command too.

Rule flush command can also safely rely on this nft_chain_binding()
check because unbound chains are not allowed since 62e1e94b246e
("netfilter: nf_tables: reject unbound chain set before commit phase").

BUG=b/302407283
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2023-5197 in the Linux kernel.

cos-patch: security-high
Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337@gmail.com>
Change-Id: Ibac98363a9fc34e3bac28a768f0172c4a4fe04d8
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/58128
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>