Revision ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 authored by Jakub Kicinski on 29 June 2022, 18:19:10 UTC, committed by Jakub Kicinski on 30 June 2022, 18:34:10 UTC
Eric reports that syzbot made short work out of my speculative
fix. Indeed when queue gets detached its tfile->tun remains,
so we would try to stop NAPI twice with a detach(), close()
sequence.

Alternative fix would be to move tun_napi_disable() to
tun_detach_all() and let the NAPI run after the queue
has been detached.

Fixes: a8fc8cb5692a ("net: tun: stop NAPI when detaching queues")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent 9c5de24
Raw File
no-block.c
// SPDX-License-Identifier: GPL-2.0-or-later
/* no-block.c: implementation of routines required for non-BLOCK configuration
 *
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/kernel.h>
#include <linux/fs.h>

static int no_blkdev_open(struct inode * inode, struct file * filp)
{
	return -ENODEV;
}

const struct file_operations def_blk_fops = {
	.open		= no_blkdev_open,
	.llseek		= noop_llseek,
};
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