[dpdk-dev] [PATCH] vhost: Fix Segmentation fault of NULL address
haifeng.lin at huawei.com
Thu Mar 26 09:29:04 CET 2015
On 2015/3/26 15:58, Qiu, Michael wrote:
> On 3/26/2015 3:52 PM, Xie, Huawei wrote:
>> On 3/26/2015 3:05 PM, Qiu, Michael wrote:
>>> Function gpa_to_vva() could return zero, while this will lead
>>> a Segmentation fault.
>>> This patch is to fix this issue.
>>> Signed-off-by: Michael Qiu <michael.qiu at intel.com>
>>> lib/librte_vhost/vhost_rxtx.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>> diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
>>> index 535c7a1..23c8acb 100644
>>> --- a/lib/librte_vhost/vhost_rxtx.c
>>> +++ b/lib/librte_vhost/vhost_rxtx.c
>>> @@ -587,6 +587,9 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
>>> /* Buffer address translation. */
>>> vb_addr = gpa_to_vva(dev, desc->addr);
>>> + if (!vb_addr)
>>> + return entry_success;
>> Firstly we should add check for all gpa_to_vva translation, and do
>> reporting and cleanup on error. We should avoid the case that some buggy
>> or malicious guest virtio driver gives us an invalid GPA(for example,
>> GPA for some MMIO space) and crash our vhost process.
> Yes, agree, I will do this for next version.
>> As we discuss, you meet segfault here, but our virtio PMD shouldn't give
>> us the GPA that has no translation, so we should root cause first and
> Yes, root cause is very important, but it will spend lots time, and I
> think we could be possible to apply this first(All check version).
How to deal with invalid address but not NULL?
>> fix the problem, and then submit the patch checking all gpa_to_vva
>>> /* Prefetch buffer address. */
>>> rte_prefetch0((void *)(uintptr_t)vb_addr);
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