diff options
| author | Jason Wang <jasowang@redhat.com> | 2016-12-23 22:37:26 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-23 13:48:54 -0500 |
| commit | 56a86f84b8332afe8c6fcb4b09d09d9bf094e2db (patch) | |
| tree | ae161601bc78368c4dcbc2adc6c9d45932f33c1b /drivers/net/virtio_net.c | |
| parent | 275be061b33b945cfb120ee8a570f78c3ccafe56 (diff) | |
| download | lwn-56a86f84b8332afe8c6fcb4b09d09d9bf094e2db.tar.gz lwn-56a86f84b8332afe8c6fcb4b09d09d9bf094e2db.zip | |
virtio-net: fix page miscount during XDP linearizing
We don't put page during linearizing, the would cause leaking when
xmit through XDP_TX or the packet exceeds PAGE_SIZE. Fix them by
put page accordingly. Also decrease the number of buffers during
linearizing to make sure caller can free buffers correctly when packet
exceeds PAGE_SIZE. With this patch, we won't get OOM after linearize
huge number of packets.
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fe4562d395e3..58ad40e17a74 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -483,7 +483,7 @@ xdp_xmit: * anymore. */ static struct page *xdp_linearize_page(struct receive_queue *rq, - u16 num_buf, + u16 *num_buf, struct page *p, int offset, unsigned int *len) @@ -497,7 +497,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, memcpy(page_address(page) + page_off, page_address(p) + offset, *len); page_off += *len; - while (--num_buf) { + while (--*num_buf) { unsigned int buflen; unsigned long ctx; void *buf; @@ -507,19 +507,22 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, if (unlikely(!ctx)) goto err_buf; + buf = mergeable_ctx_to_buf_address(ctx); + p = virt_to_head_page(buf); + off = buf - page_address(p); + /* guard against a misconfigured or uncooperative backend that * is sending packet larger than the MTU. */ - if ((page_off + buflen) > PAGE_SIZE) + if ((page_off + buflen) > PAGE_SIZE) { + put_page(p); goto err_buf; - - buf = mergeable_ctx_to_buf_address(ctx); - p = virt_to_head_page(buf); - off = buf - page_address(p); + } memcpy(page_address(page) + page_off, page_address(p) + off, buflen); page_off += buflen; + put_page(p); } *len = page_off; @@ -555,7 +558,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, /* This happens when rx buffer size is underestimated */ if (unlikely(num_buf > 1)) { /* linearize data for XDP */ - xdp_page = xdp_linearize_page(rq, num_buf, + xdp_page = xdp_linearize_page(rq, &num_buf, page, offset, &len); if (!xdp_page) goto err_xdp; |