io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid
commit 7644b1a1c9a7ae8ab99175989bfc8676055edb46 upstream.
We could race with SQ thread exit, and if we do, we'll hit a NULL pointer
dereference when the thread is cleared. Grab the SQPOLL data lock before
attempting to get the task cpu and pid for fdinfo, this ensures we have a
stable view of it.
Cherry-pick to release branch to fix CVE-2023-46862
BUG=b/309761509
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2023-46862 in the Linux kernel.
Change-Id: Ia213f5c9fe293a61e41acd38f91065c1191b5858
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/61001
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
1 file changed
