tree 1f50a7a904e2e5a42cdc548763605151f3557b0c
parent 019b13ae85260cfab9d7ccb6ca58f094d18a24fd
author Dave Watson <davejwatson@fb.com> 1498491407 -0700
committer David S. Miller <davem@davemloft.net> 1498592351 -0400

tcp: fix null ptr deref in getsockopt(..., TCP_ULP, ...)

If icsk_ulp_ops is unset, it dereferences a null ptr.
Add a null ptr check.

BUG: KASAN: null-ptr-deref in copy_to_user include/linux/uaccess.h:168 [inline]
BUG: KASAN: null-ptr-deref in do_tcp_getsockopt.isra.33+0x24f/0x1e30 net/ipv4/tcp.c:3057
Read of size 4 at addr 0000000000000020 by task syz-executor1/15452

Signed-off-by: Dave Watson <davejwatson@fb.com>
Reported-by: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>