FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050100-washday-snowdrift-2968@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 21 Apr 2026 13:24:33 -0600
Subject: [PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for
 EPOLL_URING_WAKE
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Commit:

aacf2f9f382c ("io_uring: fix req->apoll_events")

fixed an issue where poll->events and req->apoll_events weren't
synchronized, but then when the commit referenced in Fixes got added,
it didn't ensure the same thing.

If we mask in EPOLLONESHOT in the regular EPOLL_URING_WAKE path, then
ensure it's done for both. Including a link to the original report
below, even though it's mostly nonsense. But it includes a reproducer
that does show that IORING_CQE_F_MORE is set in the previous CQE,
while no more CQEs will be generated for this request. Just ignore
anything that pretends this is security related in any way, it's just
the typical AI nonsense.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/io-uring/CAM0zi7yQzF3eKncgHo4iVM5yFLAjsiob_ucqyWKs=hyd_GqiMg@mail.gmail.com/
Reported-by: Azizcan Daştan <azizcan.d@mileniumsec.com>
Fixes: 4464853277d0 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/poll.c b/io_uring/poll.c
index 6834e2db937e..0204affdc308 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -417,8 +417,10 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
 		 * disable multishot as there is a circular dependency between
 		 * CQ posting and triggering the event.
 		 */
-		if (mask & EPOLL_URING_WAKE)
+		if (mask & EPOLL_URING_WAKE) {
 			poll->events |= EPOLLONESHOT;
+			req->apoll_events |= EPOLLONESHOT;
+		}
 
 		/* optional, saves extra locking for removal in tw handler */
 		if (mask && poll->events & EPOLLONESHOT) {

Re: FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

[Jens Axboe]

On 5/1/26 5:09 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.15-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-5.15.y
> git checkout FETCH_HEAD
> git cherry-pick -x 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050100-washday-snowdrift-2968@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Not needed.

-- 
Jens Axboe

Re: FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

[Jens Axboe]

On 5/1/26 8:40 PM, Jens Axboe wrote:
> On 5/1/26 5:09 AM, gregkh@linuxfoundation.org wrote:
>>
>> The patch below does not apply to the 5.15-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-5.15.y
>> git checkout FETCH_HEAD
>> git cherry-pick -x 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5
>> # <resolve conflicts, build, test, etc.>
>> git commit -s
>> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050100-washday-snowdrift-2968@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
> 
> Not needed.

And lest we run into this again, let me preempt this by saing that no
this is not something that should get assigned a CVE.

-- 
Jens Axboe

Re: FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

[Greg KH]

On Fri, May 01, 2026 at 08:40:31PM -0600, Jens Axboe wrote:
> On 5/1/26 5:09 AM, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 5.15-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-5.15.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5
> > # <resolve conflicts, build, test, etc.>
> > git commit -s
> > git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050100-washday-snowdrift-2968@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
> 
> Not needed.

Note that the Fixes: line implies that it is needed:
	Fixes: 4464853277d0 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups")
as that has been in the following releases:
	5.10.162 5.15.90 6.1.3 6.2

which is why this, and the 5.10.y FAILED email was sent out.  Is that
marking incorrect?

thanks,

greg k-h

Re: FAILED: patch "[PATCH] io_uring/poll: ensure EPOLL_ONESHOT is propagated for" failed to apply to 5.15-stable tree

[Jens Axboe]

On 5/2/26 12:27 AM, Greg KH wrote:
> On Fri, May 01, 2026 at 08:40:31PM -0600, Jens Axboe wrote:
>> On 5/1/26 5:09 AM, gregkh@linuxfoundation.org wrote:
>>>
>>> The patch below does not apply to the 5.15-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-5.15.y
>>> git checkout FETCH_HEAD
>>> git cherry-pick -x 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5
>>> # <resolve conflicts, build, test, etc.>
>>> git commit -s
>>> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050100-washday-snowdrift-2968@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
>>
>> Not needed.
> 
> Note that the Fixes: line implies that it is needed:
> 	Fixes: 4464853277d0 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups")
> as that has been in the following releases:
> 	5.10.162 5.15.90 6.1.3 6.2
> 
> which is why this, and the 5.10.y FAILED email was sen

May be incorrect, 5.10/15 do not have the ->apoll_events cache that
newer kernels do. So likely just mistagged, which is why I'm saying it's
not needed for 5.10/15.

-- 
Jens Axboe