This is a note to let you know that I've just added the patch titled
io_uring: fix no lock protection for ctx->cq_extra
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-fix-no-lock-protection-for-ctx-cq_extra.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9280fd6ba6fe7f3a1248d91847fe6180fc420b95
Author: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Date: Thu Nov 25 17:21:02 2021 +0800
io_uring: fix no lock protection for ctx->cq_extra
[ Upstream commit e302f1046f4c209291b07ff7bc4d15ca26891f16 ]
ctx->cq_extra should be protected by completion lock so that the
req_need_defer() does the right check.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211125092103.224502-2-haoxu@xxxxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index d7e49e87b49b9..156c54ebb62b7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6573,11 +6573,14 @@ static bool io_drain_req(struct io_kiocb *req)
}
/* Still need defer if there is pending req in defer list. */
+ spin_lock(&ctx->completion_lock);
if (likely(list_empty_careful(&ctx->defer_list) &&
!(req->flags & REQ_F_IO_DRAIN))) {
+ spin_unlock(&ctx->completion_lock);
ctx->drain_active = false;
return false;
}
+ spin_unlock(&ctx->completion_lock);
seq = io_get_sequence(req);
/* Still a chance to pass the sequence check */
