diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-07-07 23:00:01 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-08 16:56:33 +0900 |
| commit | 6508b6781be076f889e3077a1a5fadf1930a569d (patch) | |
| tree | df0f6458ae9cad9b90fe0abe4dbda3dafa58ee42 /net | |
| parent | 7f93d1295131c9a8b6ff5eec13eef094f0d42921 (diff) | |
tcp: cleanup copied_seq and urg_data in tcp_disconnect
tcp_zerocopy_receive() relies on tcp_inq() to limit number of bytes
requested by user.
syzbot found that after tcp_disconnect(), tcp_inq() was returning
a stale value (number of bytes in queue before the disconnect).
Note that after this patch, ioctl(fd, SIOCINQ, &val) is also fixed
and returns 0, so this might be a candidate for all known linux kernels.
While we are at this, we probably also should clear urg_data to
avoid other syzkaller reports after it discovers how to deal with
urgent data.
syzkaller repro :
socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
bind(3, {sa_family=AF_INET, sin_port=htons(20000), sin_addr=inet_addr("224.0.0.1")}, 16) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(20000), sin_addr=inet_addr("127.0.0.1")}, 16) = 0
send(3, ..., 4096, 0) = 4096
connect(3, {sa_family=AF_UNSPEC, sa_data="\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 128) = 0
getsockopt(3, SOL_TCP, TCP_ZEROCOPY_RECEIVE, ..., [16]) = 0 // CRASH
Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c959bb6ea4ed..0d43705dd001 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2562,6 +2562,8 @@ int tcp_disconnect(struct sock *sk, int flags) tcp_clear_xmit_timers(sk); __skb_queue_purge(&sk->sk_receive_queue); + tp->copied_seq = tp->rcv_nxt; + tp->urg_data = 0; tcp_write_queue_purge(sk); tcp_fastopen_active_disable_ofo_check(sk); skb_rbtree_purge(&tp->out_of_order_queue); |