| Message ID | 20200528143407.56196-1-yuehaibing@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net-next] tipc: Fix NULL pointer dereference in __tipc_sendstream() | expand |
diff --git a/net/tipc/socket.c b/net/tipc/socket.c index d6b67d07d22e..2943561399f1 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1588,8 +1588,12 @@ static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dlen) tsk->pkt_cnt += skb_queue_len(txq); } else { skb = skb_peek_tail(txq); - msg_set_ack_required(buf_msg(skb)); - tsk->expect_ack = true; + if (skb) { + msg_set_ack_required(buf_msg(skb)); + tsk->expect_ack = true; + } else { + tsk->expect_ack = false; + } tsk->msg_acc = 0; tsk->pkt_cnt = 0; }
tipc_sendstream() may send zero length packet, then tipc_msg_append() do not alloc skb, skb_peek_tail() will get NULL, msg_set_ack_required will trigger NULL pointer dereference. Reported-by: syzbot+8eac6d030e7807c21d32@syzkaller.appspotmail.com Fixes: 0a3e060f340d ("tipc: add test for Nagle algorithm effectiveness") Signed-off-by: YueHaibing <yuehaibing@huawei.com> --- net/tipc/socket.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)