From: Eric Dumazet <eric.dumazet@gmail.com>
To: Mark Rutland <mark.rutland@arm.com>, linux-kernel@vger.kernel.org
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
"David S . Miller" <davem@davemloft.net>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
netdev@vger.kernel.org
Subject: Re: [PATCH] ipv4: fib: avoid NULL dereference
Date: Fri, 6 Jul 2018 07:47:04 -0700 [thread overview]
Message-ID: <3ad39534-400a-8d4e-ac50-94eb5655e565@gmail.com> (raw)
In-Reply-To: <20180706142836.1822-1-mark.rutland@arm.com>
On 07/06/2018 07:28 AM, Mark Rutland wrote:
> In tnode_free() we iterate over a callback_head list with a while loop.
> At the start of the loop body we generate the next head pointer, and at
> the end of the loop body we generate the tn pointer for the next
> iteration of the loop by using container_of() on the head pointer to
> find the tnode, and deriving the kv pointer from this.
>
> In the final iteration of the loop, this means that we derive a pointer
> from NULL, which is undefined behaviour, which UBSAN detects:
There is no dereference, your patch title is misleading.
UBSAN might be fooled, not the C compiler.
next prev parent reply other threads:[~2018-07-06 14:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-06 14:28 [PATCH] ipv4: fib: avoid NULL dereference Mark Rutland
2018-07-06 14:47 ` Eric Dumazet [this message]
2018-07-06 14:57 ` Mark Rutland
2018-07-06 15:39 ` Eric Dumazet
2018-07-06 15:54 ` Mark Rutland
2018-07-06 16:20 ` Eric Dumazet
2018-07-06 16:33 ` Mark Rutland
2018-07-06 16:39 ` Eric Dumazet
2018-07-06 14:49 ` David Ahern
2018-07-06 14:55 ` Mark Rutland
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