Re: [Qemu-devel] [PATCH v4 29/30] vmxnet3: validate queues configuration coming from quest

[Dmitry Fleytman]

> On Apr 1, 2014, at 5:52 PM, "Michael S. Tsirkin" <address@hidden> wrote:
> 
>> On Tue, Apr 01, 2014 at 01:04:12PM +0300, Dmitry Fleytman wrote:
>> 
>> On Mar 31, 2014, at 18:48 PM, Dr. David Alan Gilbert <address@hidden>
>> wrote:
>> 
>> 
>>    * Michael S. Tsirkin (address@hidden) wrote:
>> 
>>        From: Dmitry Fleytman <address@hidden>
>> 
>>        CVE-2013-4544
>> 
>>        Signed-off-by: Dmitry Fleytman <address@hidden>
>>        Reported-by: Michael S. Tsirkin <address@hidden>
>>        Signed-off-by: Michael S. Tsirkin <address@hidden>
>>        ---
>>        hw/net/vmxnet3.c | 13 ++++++++++++-
>>        1 file changed, 12 insertions(+), 1 deletion(-)
>> 
>>        diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
>>        index 8c6df05..0fa54e7 100644
>>        --- a/hw/net/vmxnet3.c
>>        +++ b/hw/net/vmxnet3.c
>>        @@ -1336,6 +1336,17 @@ static void vmxnet3_validate_interrupts
>>        (VMXNET3State *s)
>>            }
>>        }
>> 
>>        +static void vmxnet3_validate_queues(VMXNET3State *s)
>>        +{
>>        +    if (s->txq_num > VMXNET3_DEVICE_MAX_TX_QUEUES) {
>>        +        hw_error("Bad TX queues number: %d\n", s->txq_num);
>>        +    }
>>        +
>>        +    if (s->rxq_num > VMXNET3_DEVICE_MAX_RX_QUEUES) {
>>        +        hw_error("Bad RX queues number: %d\n", s->rxq_num);
>>        +    }
>> 
>> 
>>    Why isn't that >= ?
>>    (I agree it matches the original assert).
>> 
>>           Vmxnet3RxqDescr rxq_descr[VMXNET3_DEVICE_MAX_RX_QUEUES];
>>           Vmxnet3TxqDescr txq_descr[VMXNET3_DEVICE_MAX_TX_QUEUES];
>> 
>>    static void vmxnet3_fill_stats(VMXNET3State *s)
>>    {
>>       int i;
>>       for (i = 0; i < s->txq_num; i++) {
>>           cpu_physical_memory_write(s->txq_descr[i].tx_stats_pa,
>>                                     &s->txq_descr[i].txq_stats,
>>                                     sizeof(s->txq_descr[i].txq_stats));
>>       }
>> 
>>    so that looks like it's 0 indexed.
>> 
>>    Dave
>> 
>> 
>> HI Dave, thanks for the review.
>> 
>> The verification is ok because s->txq_num and s->rxq_num are total number of
>> queues, not a queue index.
>> 
>> Dmitry.
> 
> A code comment here might be helpful.

No problem. I'll resend these two patches with fixed comments.

> 
>> 
>> 
>> 
>> 
>>        +}
>>        +
>>        static void vmxnet3_activate_device(VMXNET3State *s)
>>        {
>>            int i;
>>        @@ -1382,7 +1393,7 @@ static void vmxnet3_activate_device(VMXNET3State
>>        *s)
>>                VMXNET3_READ_DRV_SHARED8(s->drv_shmem,
>>        devRead.misc.numRxQueues);
>> 
>>            VMW_CFPRN("Number of TX/RX queues %u/%u", s->txq_num, s->rxq_num);
>>        -    assert(s->txq_num <= VMXNET3_DEVICE_MAX_TX_QUEUES);
>>        +    vmxnet3_validate_queues(s);
>> 
>>            qdescr_table_pa =
>>                VMXNET3_READ_DRV_SHARED64(s->drv_shmem,
>>        devRead.misc.queueDescPA);
>>        -- 
>>        MST
>> 
>> 
>>    --
>>    Dr. David Alan Gilbert / address@hidden / Manchester, UK
>> 
>>