linux/net/packet
Eric Dumazet dc808110bb packet: handle too big packets for PACKET_V3
af_packet can currently overwrite kernel memory by out of bound
accesses, because it assumed a [new] block can always hold one frame.

This is not generally the case, even if most existing tools do it right.

This patch clamps too long frames as API permits, and issue a one time
error on syslog.

[  394.357639] tpacket_rcv: packet too big, clamped from 5042 to 3966. macoff=82

In this example, packet header tp_snaplen was set to 3966,
and tp_len was set to 5042 (skb->len)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: f6fb8f100b ("af-packet: TPACKET_V3 flexible buffer implementation.")
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-21 16:44:28 -07:00
..
Kconfig packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00
Makefile packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00
af_packet.c packet: handle too big packets for PACKET_V3 2014-08-21 16:44:28 -07:00
diag.c net: Use netlink_ns_capable to verify the permisions of netlink messages 2014-04-24 13:44:54 -04:00
internal.h packet: handle too big packets for PACKET_V3 2014-08-21 16:44:28 -07:00