From e302f1046f4c209291b07ff7bc4d15ca26891f16 Mon Sep 17 00:00:00 2001
From: Hao Xu <haoxu@linux.alibaba.com>
Date: Thu, 25 Nov 2021 17:21:02 +0800
Subject: [PATCH] io_uring: fix no lock protection for ctx->cq_extra
Git-commit: e302f1046f4c209291b07ff7bc4d15ca26891f16
Patch-mainline: v5.17-rc1
References: bsc#1205205
ctx->cq_extra should be protected by completion lock so that the
req_need_defer() does the right check.
Cc: stable@vger.kernel.org
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211125092103.224502-2-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
fs/io_uring.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f666a0e7f5e8..ae9534382b26 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6537,12 +6537,15 @@ static __cold void io_drain_req(struct io_kiocb *req)
u32 seq = io_get_sequence(req);
/* Still need defer if there is pending req in defer list. */
+ spin_lock(&ctx->completion_lock);
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) {
+ spin_unlock(&ctx->completion_lock);
queue:
ctx->drain_active = false;
io_req_task_queue(req);
return;
}
+ spin_unlock(&ctx->completion_lock);
ret = io_req_prep_async(req);
if (ret) {
--
2.35.3