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From: Aaron Conole <aconole@redhat.com>
To: Olivier Matz <olivier.matz@6wind.com>
Cc: Thomas Monjalon <thomas@monjalon.net>,
	Wenwu Ma <wenwux.ma@intel.com>,
	andrew.rybchenko@oktetlabs.ru, stable@dpdk.org, dev@dpdk.org,
	zhihongx.peng@intel.com
Subject: Re: [dpdk-dev] [dpdk-stable] [v2] test/mempool: fix heap buffer overflow
Date: Thu, 15 Apr 2021 08:51:27 -0400	[thread overview]
Message-ID: <f7tk0p3aey8.fsf@dhcp-25.97.bos.redhat.com> (raw)
In-Reply-To: <20210415064521.GE1650@platinum> (Olivier Matz's message of "Thu,  15 Apr 2021 08:45:21 +0200")

Olivier Matz <olivier.matz@6wind.com> writes:

> On Tue, Apr 13, 2021 at 01:52:26PM +0200, Thomas Monjalon wrote:
>> 13/04/2021 22:05, Wenwu Ma:
>> > Amount of allocated memory was not enough for mempool
>> > which cause buffer overflow when access fields of mempool
>> > private structure in the rte_pktmbuf_priv_size function.
>>
>> Was it causing the test to fail?
>> How do you reproduce the overflow?
>
> In the test, right after the rte_mempool_create(), the function
> rte_mempool_obj_iter() is called too initialize the mempool objects with
> the rte_pktmbuf_init() callback function. This callback expects that the
> mempool is a packet pool, i.e. its private area is a struct
> rte_pktmbuf_pool_private structure.
>
> In the current test, the size of the private area is 0, which probably
> causes the function rte_pktmbuf_priv_size() to return an unpredictable
> value, and this value is used as a size in a memset.

Is it possible to have rte_mempool_get_priv() detect that the private
area isn't valid and return a ref to a const static member for this that
will have the correct mbuf_priv_size?  There isn't really documentation
that I can find that describes this corner case with the mempool private
data section.  Actually, it doesn't really say what happens if private
data size is 0, so maybe a documentation update should go with this test
case fix, too?

> This part of the test was added in commit 923ceaeac140 ("test/mempool:
> add unit test cases").
>
> Instead of changing the size of the private area like done in the patch,
> I suggest to use another callback than rte_pktmbuf_init(). After all,
> this is a mempool test, so we should not rely on mbuf features. The
> function my_obj_init() could be used like in other places of the test,
> like this:
>
>   @@ -552,7 +552,7 @@ test_mempool(void)
>   		 GOTO_ERR(ret, err);
>   
>   	 /* test to initialize mempool objects and memory */
>   -        nb_objs = rte_mempool_obj_iter(mp_stack_mempool_iter, rte_pktmbuf_init,
>   +        nb_objs = rte_mempool_obj_iter(mp_stack_mempool_iter, my_obj_init,
>   			 NULL);
>   	 if (nb_objs == 0)
>   		 GOTO_ERR(ret, err);
>
>
> Wenwu, does it solve your issue?
>
>
> Regards,
> Olivier


  reply	other threads:[~2021-04-15 12:51 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-31 21:05 [dpdk-dev] [PATCH] test/mempool: Fix illegal pointer access in mempool test Wenwu Ma
2021-04-13 20:05 ` [dpdk-dev] [v2] test/mempool: fix heap buffer overflow Wenwu Ma
2021-04-13 11:52   ` [dpdk-dev] [dpdk-stable] " Thomas Monjalon
2021-04-15  6:45     ` Olivier Matz
2021-04-15 12:51       ` Aaron Conole [this message]
2021-04-16  7:20         ` Olivier Matz
2021-04-27 13:56   ` [dpdk-dev] [PATCH v3 1/2] " Olivier Matz
2021-04-27 13:56     ` [dpdk-dev] [PATCH v3 2/2] mbuf: better document usage of packet pool initializers Olivier Matz
2021-04-27 14:22       ` Aaron Conole
2021-05-04 18:07     ` [dpdk-dev] [dpdk-stable] [PATCH v3 1/2] test/mempool: fix heap buffer overflow Thomas Monjalon
2021-04-15  2:04 ` [dpdk-dev] [PATCH] test/mempool: Fix illegal pointer access in mempool test Peng, ZhihongX

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