tree ae0b24f150eebd9426b7d9fa5f10d402bee8c031
parent 64f3f5392bbe5ffd7184b20121dfd6d9befbea41
author Lee Jones <lee@kernel.org> 1658231571 +0100
committer Vaibhav Rustagi <vaibhavrustagi@google.com> 1664946554 +0000

io_uring: Use original task for req identity in io_identity_cow()

This issue is conceptually identical to the one fixed in 29f077d07051
("io_uring: always use original task when preparing req identity"), so
rather than reinvent the wheel, I'm shamelessly quoting the commit
message from that patch - thanks Jens:

 "If the ring is setup with IORING_SETUP_IOPOLL and we have more than
  one task doing submissions on a ring, we can up in a situation where
  we assign the context from the current task rather than the request
  originator.

  Always use req->task rather than assume it's the same as current.

  No upstream patch exists for this issue, as only older kernels with
  the non-native workers have this problem."

BUG=b/250926117
TEST=presubmit
RELEASE_NOTE=None

cos-patch: bug
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: io-uring@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Fixes: 5c3462cfd123b ("io_uring: store io_identity in io_uring_task")
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 2ee0cab11f6626071f8a64c7792406dabdd94c8d)
Signed-off-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Change-Id: Idd81cec7b831f6de22291db84582ea714fc835af
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/37389
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>