From: David Miller <davem@davemloft.net>
To: xi.wang@gmail.com
Cc: eric.dumazet@gmail.com, therbert@google.com, netdev@vger.kernel.org
Subject: Re: [PATCH v2] rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt()
Date: Thu, 22 Dec 2011 22:37:38 -0500 (EST) [thread overview]
Message-ID: <20111222.223738.869939610976955478.davem@davemloft.net> (raw)
In-Reply-To: <4EF3BEBA.4040402@gmail.com>
From: Xi Wang <xi.wang@gmail.com>
Date: Thu, 22 Dec 2011 18:35:22 -0500
> Setting a large rps_flow_cnt like (1 << 30) on 32-bit platform will
> cause a kernel oops due to insufficient bounds checking.
>
> if (count > 1<<30) {
> /* Enforce a limit to prevent overflow */
> return -EINVAL;
> }
> count = roundup_pow_of_two(count);
> table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));
>
> Note that the macro RPS_DEV_FLOW_TABLE_SIZE(count) is defined as:
>
> ... + (count * sizeof(struct rps_dev_flow))
>
> where sizeof(struct rps_dev_flow) is 8. (1 << 30) * 8 will overflow
> 32 bits.
>
> This patch replaces the magic number (1 << 30) with a symbolic bound.
>
> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Xi Wang <xi.wang@gmail.com>
Applied.
next prev parent reply other threads:[~2011-12-23 3:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-21 18:50 [PATCH] rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt() Xi Wang
2011-12-21 19:22 ` Eric Dumazet
2011-12-21 19:41 ` David Miller
2011-12-21 23:41 ` Xi Wang
2011-12-22 23:35 ` [PATCH v2] " Xi Wang
2011-12-23 3:37 ` David Miller [this message]
2011-12-23 4:10 ` Eric Dumazet
2011-12-23 4:44 ` Xi Wang
2011-12-23 4:53 ` Eric Dumazet
2011-12-23 5:10 ` Xi Wang
2011-12-23 5:16 ` Eric Dumazet
2011-12-23 5:35 ` Eric Dumazet
2011-12-23 5:56 ` Xi Wang
2011-12-23 13:06 ` Eric Dumazet
2011-12-23 14:30 ` Xi Wang
2011-12-23 14:53 ` Eric Dumazet
2011-12-23 15:07 ` Xi Wang
2011-12-24 16:56 ` [PATCH net-next] rfs: better sizing of dev_flow_table Eric Dumazet
2011-12-24 21:19 ` David Miller
2011-12-23 5:49 ` [PATCH v2] rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt() Xi Wang
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