FAILED: patch "[PATCH] io_uring/wait: fix min_timeout behavior" failed to apply to 6.12-stable tree

FAILED: patch "[PATCH] io_uring/wait: fix min_timeout behavior" failed to apply to 6.12-stable tree

[gregkh]

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 29fe1bd01b99714f3136f922230a643c2742cda9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026061511-underhand-neuron-492c@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 29fe1bd01b99714f3136f922230a643c2742cda9 Mon Sep 17 00:00:00 2001
From: "Christian A. Ehrhardt" <lk@c--e.de>
Date: Sat, 6 Jun 2026 22:11:20 +0200
Subject: [PATCH] io_uring/wait: fix min_timeout behavior

The wakeup condition if a min timeout is present and has expired is that
at least _one_ CQE was posted. Thus set the cq_tail target to
->cq_min_tail + 1. Without this commit a spurious wakeup can result in a
premature wakeup because io_should_wake() will return true even if _no_
CQE was posted at all.

Cc: Tip ten Brink <tip@tenbrinkmeijs.com>
Fixes: e15cb2200b93 ("io_uring: fix min_wait wakeups for SQPOLL")
Cc: stable@vger.kernel.org
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Link: https://patch.msgid.link/20260606201120.1441447-1-lk@c--e.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/wait.c b/io_uring/wait.c
index ec01e78a216d..d005ea17b35f 100644
--- a/io_uring/wait.c
+++ b/io_uring/wait.c
@@ -103,7 +103,7 @@ static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)
 	}
 
 	/* any generated CQE posted past this time should wake us up */
-	iowq->cq_tail = iowq->cq_min_tail;
+	iowq->cq_tail = iowq->cq_min_tail + 1;
 
 	hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup);
 	hrtimer_set_expires(timer, iowq->timeout);

Re: FAILED: patch "[PATCH] io_uring/wait: fix min_timeout behavior" failed to apply to 6.12-stable tree

[Jens Axboe]

[-- Attachment #1: Type: text/plain, Size: 340 bytes --]

On 6/15/26 8:18 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 6.12-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Here's one for 6.12-stable.

-- 
Jens Axboe

[-- Attachment #2: 0001-io_uring-wait-fix-min_timeout-behavior.patch --]
[-- Type: text/x-patch, Size: 1453 bytes --]

From e68b3e06b410a794322c65449e4357889a5e3e4f Mon Sep 17 00:00:00 2001
From: "Christian A. Ehrhardt" <lk@c--e.de>
Date: Sat, 6 Jun 2026 22:11:20 +0200
Subject: [PATCH 1/2] io_uring/wait: fix min_timeout behavior

Commit 29fe1bd01b99714f3136f922230a643c2742cda9 upstream.

The wakeup condition if a min timeout is present and has expired is that
at least _one_ CQE was posted. Thus set the cq_tail target to
->cq_min_tail + 1. Without this commit a spurious wakeup can result in a
premature wakeup because io_should_wake() will return true even if _no_
CQE was posted at all.

Cc: Tip ten Brink <tip@tenbrinkmeijs.com>
Fixes: e15cb2200b93 ("io_uring: fix min_wait wakeups for SQPOLL")
Cc: stable@vger.kernel.org
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Link: https://patch.msgid.link/20260606201120.1441447-1-lk@c--e.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index e515aeafa878..03c6ab505d74 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2414,7 +2414,7 @@ static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)
 	}
 
 	/* any generated CQE posted past this time should wake us up */
-	iowq->cq_tail = iowq->cq_min_tail;
+	iowq->cq_tail = iowq->cq_min_tail + 1;
 
 	iowq->t.function = io_cqring_timer_wakeup;
 	hrtimer_set_expires(timer, iowq->timeout);
-- 
2.53.0