fuse: Fix use-after-free in fuse_dev_do_read()
commit bc78abbd55dd28e2287ec6d6502b842321a17c87 upstream.
We may pick freed req in this way:
[cpu0] [cpu1]
fuse_dev_do_read() fuse_dev_do_write()
list_move_tail(&req->list, ...); ...
spin_unlock(&fpq->lock); ...
... request_end(fc, req);
... fuse_put_request(fc, req);
if (test_bit(FR_INTERRUPTED, ...))
queue_interrupt(fiq, req);
Fix that by keeping req alive until we finish all manipulations.
Reported-by: syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 46c34a348b0a ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed