tree 781677be717b11066e303449ee4abd787048816e
parent 9512925a2cc2b1cd0206bb93bad200a69716f998
author Eric Dumazet <edumazet@google.com> 1478098397 -0700
committer David S. Miller <davem@davemloft.net> 1478201610 -0400

tcp: fix potential memory corruption

Imagine initial value of max_skb_frags is 17, and last
skb in write queue has 15 frags.

Then max_skb_frags is lowered to 14 or smaller value.

tcp_sendmsg() will then be allowed to add additional page frags
and eventually go past MAX_SKB_FRAGS, overflowing struct
skb_shared_info.

Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Cc: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>