dccp: fix freeing skb too early for IPV6_RECVPKTINFO
authorAndrey Konovalov <andreyknvl@google.com>
Thu, 16 Feb 2017 16:22:46 +0000 (17:22 +0100)
committerDavid S. Miller <davem@davemloft.net>
Fri, 17 Feb 2017 18:36:25 +0000 (13:36 -0500)
commit5edabca9d4cff7f1f2b68f0bac55ef99d9798ba4
tree6472d92163649ed669f5814120ecf500765a0548
parent785f35775d968e0f45231b754e945fcb3ed6bded
dccp: fix freeing skb too early for IPV6_RECVPKTINFO

In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet
is forcibly freed via __kfree_skb in dccp_rcv_state_process if
dccp_v6_conn_request successfully returns.

However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb
is saved to ireq->pktopts and the ref count for skb is incremented in
dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed
in dccp_rcv_state_process.

Fix by calling consume_skb instead of doing goto discard and therefore
calling __kfree_skb.

Similar fixes for TCP:

fb7e2399ec17f1004c0e0ccfd17439f8759ede01 [TCP]: skb is unexpectedly freed.
0aea76d35c9651d55bbaf746e7914e5f9ae5a25d tcp: SYN packets are now
simply consumed

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/dccp/input.c