Messages in this thread Patch in this message | | | From | Jason Wang <> | Subject | [PATCH net 3/3] virtio-net: fix resources leaking when fail to allocate frag skb | Date | Wed, 20 Nov 2013 17:07:27 +0800 |
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When we fail to allocate a frag skb, we need put the refcnt of the page and drop the rest of the buffers. Otherwise the page was leaked and driver won't get a correct head buffer after this failure.
This bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a (virtio_net: migrate mergeable rx buffers to page frag allocators).
Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michael Dalton <mwdalton@google.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- The patch was needed for 3.12 stable. --- drivers/net/virtio_net.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index de1d6ca..f6f1e20 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -339,9 +339,12 @@ static int receive_mergeable(struct receive_queue *rq, struct sk_buff *head_skb) head_skb->dev->name); len = MERGE_BUFFER_LEN; } + page = virt_to_head_page(buf); if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) { struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC); if (unlikely(!nskb)) { + put_page(page); + drop_mergeable_buffer(rq, num_buf); head_skb->dev->stats.rx_dropped++; return -ENOMEM; } @@ -358,7 +361,6 @@ static int receive_mergeable(struct receive_queue *rq, struct sk_buff *head_skb) head_skb->len += len; head_skb->truesize += MERGE_BUFFER_LEN; } - page = virt_to_head_page(buf); offset = buf - (char *)page_address(page); if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { put_page(page); -- 1.8.3.2
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