path: root/drivers/net
diff options
authorWillem de Bruijn <willemb@google.com>2017-02-07 15:57:20 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-18 16:39:27 +0100
commit58691e5b4f277cf1876dc95654a794b093f88a0f (patch)
tree0b10eab71333229744772722d77d0fa976747a46 /drivers/net
parent6f99825e7632ba94b0e5f9986e5f64d9eb9370b1 (diff)
net: introduce device min_header_len
[ Upstream commit 217e6fa24ce28ec87fca8da93c9016cb78028612 ] The stack must not pass packets to device drivers that are shorter than the minimum link layer header length. Previously, packet sockets would drop packets smaller than or equal to dev->hard_header_len, but this has false positives. Zero length payload is used over Ethernet. Other link layer protocols support variable length headers. Support for validation of these protocols removed the min length check for all protocols. Introduce an explicit dev->min_header_len parameter and drop all packets below this value. Initially, set it to non-zero only for Ethernet and loopback. Other protocols can follow in a patch to net-next. Fixes: 9ed988cd5915 ("packet: validate variable length ll headers") Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index dc7d970bd1c0..effcdbfb06e9 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -164,6 +164,7 @@ static void loopback_setup(struct net_device *dev)
dev->mtu = 64 * 1024;
dev->hard_header_len = ETH_HLEN; /* 14 */
+ dev->min_header_len = ETH_HLEN; /* 14 */
dev->addr_len = ETH_ALEN; /* 6 */
dev->type = ARPHRD_LOOPBACK; /* 0x0001*/
dev->flags = IFF_LOOPBACK;