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author | Herbert Xu <herbert@gondor.apana.org.au> | 2009-06-08 00:20:01 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2009-06-08 00:20:01 -0700 |
commit | 4909122fb8350e70c347f1201256908a92058044 (patch) | |
tree | ce87843cec44a1671bacff61b2c4fd25960efa6a | |
parent | b82f08ea162edeee6c2c70c6c4321bea4763fa35 (diff) | |
download | linux-3.10-4909122fb8350e70c347f1201256908a92058044.tar.gz linux-3.10-4909122fb8350e70c347f1201256908a92058044.tar.bz2 linux-3.10-4909122fb8350e70c347f1201256908a92058044.zip |
tun: Optimise handling of bogus gso->hdr_len
As all current versions of virtio_net generate a value for the
header length that's too small, we should optimise this so that
we don't copy it twice. This can be done by ensuring that it is
at least as large as the place where we'll write the checksum.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | drivers/net/tun.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 3f0cdc14be8..8d82511aa1b 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -565,6 +565,10 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) return -EFAULT; + if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) + gso.hdr_len = gso.csum_start + gso.csum_offset + 2; + if (gso.hdr_len > len) return -EINVAL; offset += sizeof(pi); |