diff options
| author | Willem de Bruijn <willemb@google.com> | 2016-03-08 15:18:54 -0500 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-10 23:07:03 -0400 |
| commit | 686263920d666722c42b5347123113bd85ec67cc (patch) | |
| tree | 072d1324dba89badc8d48c1ef68dbfcf7fc63663 /drivers/net | |
| parent | 5284ee1e9da2f8f78b5b800109ef4c436c58876d (diff) | |
macvtap: always pass ethernet header in linear
[ Upstream commit 8e2ad4113ce4671686740f808ff2795395c39eef ]
The stack expects link layer headers in the skb linear section.
Macvtap can create skbs with llheader in frags in edge cases:
when (IFF_VNET_HDR is off or vnet_hdr.hdr_len < ETH_HLEN) and
prepad + len > PAGE_SIZE and vnet_hdr.flags has no or bad csum.
Add checks to ensure linear is always at least ETH_HLEN.
At this point, len is already ensured to be >= ETH_HLEN.
For backwards compatiblity, rounds up short vnet_hdr.hdr_len.
This differs from tap and packet, which return an error.
Fixes b9fb9ee07e67 ("macvtap: add GSO/csum offload support")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/macvtap.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 4dba5fbc735e..2b212f3e140c 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -710,6 +710,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; if (copylen > good_linear) copylen = good_linear; + else if (copylen < ETH_HLEN) + copylen = ETH_HLEN; linear = copylen; i = *from; iov_iter_advance(&i, copylen); @@ -719,10 +721,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, if (!zerocopy) { copylen = len; - if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear) + linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len); + if (linear > good_linear) linear = good_linear; - else - linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len); + else if (linear < ETH_HLEN) + linear = ETH_HLEN; } skb = macvtap_alloc_skb(&q->sk, MACVTAP_RESERVE, copylen, |