dccp: fix out of bound access in dccp_v4_err()
authorEric Dumazet <edumazet@google.com>
Thu, 3 Nov 2016 02:00:40 +0000 (19:00 -0700)
committerDavid S. Miller <davem@davemloft.net>
Thu, 3 Nov 2016 20:16:51 +0000 (16:16 -0400)
commit6706a97fec963d6cb3f7fc2978ec1427b4651214
treecbe6c56ae8eadfb5472dc23fade4158f5e311120
parent346da62cc186c4b4b1ac59f87f4482b47a047388
dccp: fix out of bound access in dccp_v4_err()

dccp_v4_err() does not use pskb_may_pull() and might access garbage.

We only need 4 bytes at the beginning of the DCCP header, like TCP,
so the 8 bytes pulled in icmp_socket_deliver() are more than enough.

This patch might allow to process more ICMP messages, as some routers
are still limiting the size of reflected bytes to 28 (RFC 792), instead
of extended lengths (RFC 1812 4.3.2.3)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/dccp/ipv4.c