All of lore.kernel.org
 help / color / mirror / Atom feed
* FAILED: patch "[PATCH] fuse: wait for FR_FINISHED on abort_on_kill to prevent" failed to apply to 6.18-stable tree
@ 2026-08-31 12:23 gregkh
  2026-08-31 16:42 ` [PATCH 6.18.y 1/4] fuse: abort related layering cleanup Sasha Levin
  0 siblings, 1 reply; 6+ messages in thread
From: gregkh @ 2026-08-31 12:23 UTC (permalink / raw)
  To: rochan.avlur, mszeredi; +Cc: stable


The patch below does not apply to the 6.18-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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 64b0b5cacbd2fea88001464cb712c9dfc795b26e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026083101-rimless-sadness-3898@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 64b0b5cacbd2fea88001464cb712c9dfc795b26e Mon Sep 17 00:00:00 2001
From: Rochan Avlur <rochan.avlur@gmail.com>
Date: Wed, 12 Aug 2026 20:58:36 -0700
Subject: [PATCH] fuse: wait for FR_FINISHED on abort_on_kill to prevent
 use-after-free

The abort_on_kill path in request_wait_answer() calls fuse_abort_conn()
and returns without waiting for FR_FINISHED.  If fuse_dev_do_write() is
concurrently processing the same request (FR_LOCKED set), the caller
frees req->args while it is still being accessed, causing a
use-after-free.

Fix this by jumping to the existing wait_event(FR_FINISHED) instead of
returning early.  The wait will not hang because fuse_abort_conn()
ensures all requests are ended.

Reported-by: syzbot+d6540a3fa1626e11360d@syzkaller.appspotmail.com
Fixes: 204aa22a686b ("fuse: abort on fatal signal during sync init")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Rochan Avlur <rochan.avlur@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 90dceb7da571..34106f6e66a0 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -724,7 +724,7 @@ static void request_wait_answer(struct fuse_req *req)
 
 		if (req->args->abort_on_kill) {
 			fuse_chan_abort(fch, false);
-			return;
+			goto wait_for_finish;
 		}
 
 		if (test_bit(FR_URING, &req->flags))
@@ -735,6 +735,7 @@ static void request_wait_answer(struct fuse_req *req)
 			return;
 	}
 
+wait_for_finish:
 	/*
 	 * Either request is already in userspace, or it was forced.
 	 * Wait it out.


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2026-09-09 12:34 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-31 12:23 FAILED: patch "[PATCH] fuse: wait for FR_FINISHED on abort_on_kill to prevent" failed to apply to 6.18-stable tree gregkh
2026-08-31 16:42 ` [PATCH 6.18.y 1/4] fuse: abort related layering cleanup Sasha Levin
2026-08-31 16:42   ` [PATCH 6.18.y 2/4] fuse: split off fuse_args and related definitions into a separate header Sasha Levin
2026-08-31 16:42   ` [PATCH 6.18.y 3/4] fuse: remove fm arg of args->end callback Sasha Levin
2026-08-31 16:42   ` [PATCH 6.18.y 4/4] fuse: wait for FR_FINISHED on abort_on_kill to prevent use-after-free Sasha Levin
2026-09-09 12:33   ` [PATCH 6.18.y 1/4] fuse: abort related layering cleanup Greg KH

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.