fuse: wait for FR_FINISHED on abort_on_kill to prevent use-after-free

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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: 204aa22a68 ("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>

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Rochan Avlur 2026-08-12 20:58:36 -07:00 • committed by Miklos Szeredi

parent 6e64df0f73

commit 64b0b5cacb

1 changed files with 2 additions and 1 deletions

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fs/fuse/dev.c

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