tree 9b87c637727d62852c0335872595e8e14b2dc489
parent 293de7dee4f9602676846dbeb84b1580123306b4
author Xin Long <lucien.xin@gmail.com> 1477242069 +0800
committer David S. Miller <davem@davemloft.net> 1477517539 -0400

sctp: fix the panic caused by route update

Commit 7303a1475008 ("sctp: identify chunks that need to be fragmented
at IP level") made the chunk be fragmented at IP level in the next round
if it's size exceed PMTU.

But there still is another case, PMTU can be updated if transport's dst
expires and transport's pmtu_pending is set in sctp_packet_transmit. If
the new PMTU is less than the chunk, the same issue with that commit can
be triggered.

So we should drop this packet and let it retransmit in another round
where it would be fragmented at IP level.

This patch is to fix it by checking the chunk size after PMTU may be
updated and dropping this packet if it's size exceed PMTU.

Fixes: 90017accff61 ("sctp: Add GSO support")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@txudriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>