| Message ID | 1459233953-4745-1-git-send-email-fanhui00@gmail.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
From: fanhui <fanhui00@gmail.com> Date: Tue, 29 Mar 2016 14:45:53 +0800 > [<ffffffc000930718>] tcp_nuke_addr+0x22c/0x2a0 Do not report or fix problems in non-mainline kernels. Thank you.
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index bc68ece..742c618 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -112,11 +112,14 @@ static void __inet_put_port(struct sock *sk) spin_lock(&head->lock); tb = inet_csk(sk)->icsk_bind_hash; + if (!tb) + goto out; __sk_del_bind_node(sk); tb->num_owners--; inet_csk(sk)->icsk_bind_hash = NULL; inet_sk(sk)->inet_num = 0; inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); +out: spin_unlock(&head->lock); }
There may be race condition when accessing inet_csk(sk)->icsk_bind_hash, which leads to a crash like this: Unable to handle kernel NULL pointer dereference at virtual address 00000010 ...... [<ffffffc000929140>] inet_put_port+0x80/0xb8 [<ffffffc00092c4bc>] tcp_set_state+0xc4/0x110 [<ffffffc00092ce68>] tcp_done+0x60/0xb8 [<ffffffc000930718>] tcp_nuke_addr+0x22c/0x2a0 [<ffffffc000950558>] devinet_ioctl+0x294/0x680 [<ffffffc000951e68>] inet_ioctl+0xd4/0x100 [<ffffffc00089fd04>] sock_do_ioctl+0x40/0x70 [<ffffffc0008a0238>] sock_ioctl+0x288/0x2a8 [<ffffffc000193358>] do_vfs_ioctl+0x4b4/0x588 [<ffffffc000193494>] SyS_ioctl+0x68/0x94 ...... Signed-off-by: fanhui <fanhui00@gmail.com> --- net/ipv4/inet_hashtables.c | 3 +++ 1 file changed, 3 insertions(+)