UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

tcp: fix a possible lockdep splat in tcp_done() 

syzbot found that if __inet_inherit_port() returns an error,
we call tcp_done() after inet_csk_prepare_forced_close(),
meaning the socket lock is no longer held.

We might fix this in a different way in net-next, but
for 5.4 it seems safer to relax the lockdep check.

Fixes: d983ea6f16 ("tcp: add rcu protection around tp->fastopen_rsk")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2019-10-14 06:47:57 -07:00 committed by David S. Miller
parent c9b96eb6da
commit cab209e571
1 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
net/ipv4/tcp.c
View File

@ -3842,8 +3842,12 @@ void tcp_done(struct sock *sk)
{ {
struct request_sock *req; struct request_sock *req;
req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, /* We might be called with a new socket, after
lockdep_sock_is_held(sk)); * inet_csk_prepare_forced_close() has been called
* so we can not use lockdep_sock_is_held(sk)
*/
req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1);
if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);