net/sched: cls_route: No longer copy tcf_result on update to avoid use-after-free
[ Upstream commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8 ]
When route4_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
BUG=b/296442227
SOURCE=UPSTREAM(b80b829e9e2c)
TEST=presubmit
RELEASE_NOTE=None
cos-patch: security-high
Fixes: 1109c00547fc ("net: sched: RCU cls_route")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Change-Id: If38d82bccceccd4abf65d6765acc30fadfc8cdc9
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/55578
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
1 file changed
