packet: fix match_fanout_group()

Browse source

commit 161642e24f upstream.

Recent TCP listener patches exposed a prior af_packet bug :
match_fanout_group() blindly assumes it is always safe
to cast sk to a packet socket to compare fanout with af_packet_priv

But SYNACK packets can be sent while attached to request_sock, which
are smaller than a "struct sock".

We can read non existent memory and crash.

Fixes: c0de08d042 ("af_packet: don't emit packet on orig fanout group")
Fixes: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Eric Leblond <eric@regit.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

...

This commit is contained in:

Eric Dumazet 2015-10-09 11:29:32 -07:00 • committed by Luis Henriques

parent 9c84eab050

commit d1011c5cc5

1 changed files with 3 additions and 3 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

6

net/packet/af_packet.c

View file