korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 21:38:32 +08:00
Code Issues Packages Projects Releases Wiki Activity

io_uring: fix drain stalls by invalid SQE

Browse Source 
[ Upstream commit cfdbaa3a29 ]

cq_extra is protected by ->completion_lock, which io_get_sqe() misses.
The bug is harmless as it doesn't happen in real life, requires invalid
SQ index array and racing with submission, and only messes up the
userspace, i.e. stall requests execution but will be cleaned up on
ring destruction.

Fixes: 15641e4270 ("io_uring: don't cache number of dropped SQEs")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/66096d54651b1a60534bb2023f2947f09f50ef73.1691538547.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pavel Begunkov 2023-08-09 13:21:41 +01:00 committed by Greg Kroah-Hartman
parent 9183c4fe91
commit 0c323430e4
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
io_uring/io_uring.c
View File

@ -2240,7 +2240,9 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
}
/* drop invalid entries */
spin_lock(&ctx->completion_lock);
ctx->cq_extra--;
spin_unlock(&ctx->completion_lock);
WRITE_ONCE(ctx->rings->sq_dropped,
READ_ONCE(ctx->rings->sq_dropped) + 1);
return NULL;