On Tue, Nov 19, 2013 at 05:34:16PM -0800, Michael Dalton wrote: > Hi, > > After further reflection I think we're looking at two related issues: > (a) a memory leak that Jason has identified that occurs when a memory > allocation fails in receive_mergeable. Jasons commit solves this issue. > (b) virtio-net does not dequeue all buffers for a packet in the > case that an error occurs on receive and mergeable receive buffers is > enabled. > > For (a), this bug is new and due to changes in 2613af0ed18a, and the > net impact is memory leak on the physical page. However, I believe (b) > has always been possible in some form because if page_to_skb() returns > NULL (e.g., due to SKB allocation failure), receive_mergeable is never > called. AFAICT this is also the behavior prior to 2613af0ed18a. > > The net impact of (b) would be that virtio-net would interpret a packet > buffer that is in the middle of a mergeable packet as the start of a > new packet, which is definitely also a bug (and the buffer contents > could contain bytes that resembled a valid virtio-net header). > > A solution for (b) will require handling both the page_to_skb memory > allocation failures and the memory allocation failures in > receive_mergeable introduced by 2613af0ed18a. > > Best, > > Mike
Absolutely. I missed this fact yesterday night but I can see it clearly in the morning. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
