From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Marc Kleine-Budde <mkl@pengutronix.de>,
Andrey Konovalov <andreyknvl@google.com>,
"David S. Miller" <davem@davemloft.net>,
linux-can@vger.kernel.org, netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Kostya Serebryany <kcc@google.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: net/can: warning in raw_setsockopt/__alloc_pages_slowpath
Date: Fri, 2 Dec 2016 16:11:41 +0100 [thread overview]
Message-ID: <73b78023-bc11-25c0-33e3-3a748dbc81cd@hartkopp.net> (raw)
In-Reply-To: <c47865a1-4aae-5eae-f9e0-7b4f7f7e9897@pengutronix.de>
On 12/02/2016 02:24 PM, Marc Kleine-Budde wrote:
> On 12/02/2016 01:43 PM, Andrey Konovalov wrote:
>> [<ffffffff8369e0de>] raw_setsockopt+0x1be/0x9f0 net/can/raw.c:506
>
> We should add a check for a sensible optlen....
>
>> static int raw_setsockopt(struct socket *sock, int level, int optname,
>> char __user *optval, unsigned int optlen)
>> {
>> struct sock *sk = sock->sk;
>> struct raw_sock *ro = raw_sk(sk);
>> struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
>> struct can_filter sfilter; /* single filter */
>> struct net_device *dev = NULL;
>> can_err_mask_t err_mask = 0;
>> int count = 0;
>> int err = 0;
>>
>> if (level != SOL_CAN_RAW)
>> return -EINVAL;
>>
>> switch (optname) {
>>
>> case CAN_RAW_FILTER:
>> if (optlen % sizeof(struct can_filter) != 0)
>> return -EINVAL;
>
> here...
>
> if (optlen > 64 * sizeof(struct can_filter))
> return -EINVAL;
>
Agreed.
But what is sensible here?
64 filters is way to small IMO.
When thinking about picking a bunch of single CAN IDs I would tend to
something like 512 filters.
Regards,
Oliver
>>
>> count = optlen / sizeof(struct can_filter);
>>
>> if (count > 1) {
>> /* filter does not fit into dfilter => alloc space */
>> filter = memdup_user(optval, optlen);
>> if (IS_ERR(filter))
>> return PTR_ERR(filter);
>> } else if (count == 1) {
>> if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
>> return -EFAULT;
>> }
>>
>> lock_sock(sk);
>
> Marc
>
next prev parent reply other threads:[~2016-12-02 15:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 12:43 net/can: warning in raw_setsockopt/__alloc_pages_slowpath Andrey Konovalov
2016-12-02 13:24 ` Marc Kleine-Budde
2016-12-02 15:11 ` Oliver Hartkopp [this message]
2016-12-02 15:42 ` Marc Kleine-Budde
2016-12-02 17:05 ` Oliver Hartkopp
2016-12-05 10:55 ` Marc Kleine-Budde
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