From 1c24285372412b26af4f0f980c115e857fb87c02 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Mon, 7 Aug 2017 14:31:20 +0800 Subject: [PATCH] dlm: use sock_create_lite inside tcp_accept_from_sock With commit 0ffdaf5b41cf ("net/sock: add WARN_ON(parent->sk) in sock_graft()"), a calltrace happened as follows: [ 457.018340] WARNING: CPU: 0 PID: 15623 at ./include/net/sock.h:1703 inet_accept+0x135/0x140 ... [ 457.018381] RIP: 0010:inet_accept+0x135/0x140 [ 457.018381] RSP: 0018:ffffc90001727d18 EFLAGS: 00010286 [ 457.018383] RAX: 0000000000000001 RBX: ffff880012413000 RCX: 0000000000000001 [ 457.018384] RDX: 000000000000018a RSI: 00000000fffffe01 RDI: ffffffff8156fae8 [ 457.018384] RBP: ffffc90001727d38 R08: 0000000000000000 R09: 0000000000004305 [ 457.018385] R10: 0000000000000001 R11: 0000000000004304 R12: ffff880035ae7a00 [ 457.018386] R13: ffff88001282af10 R14: ffff880034e4e200 R15: 0000000000000000 [ 457.018387] FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 [ 457.018388] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 457.018389] CR2: 00007fdec22f9000 CR3: 0000000002b5a000 CR4: 00000000000006f0 [ 457.018395] Call Trace: [ 457.018402] tcp_accept_from_sock.part.8+0x12d/0x449 [dlm] [ 457.018405] ? vprintk_emit+0x248/0x2d0 [ 457.018409] tcp_accept_from_sock+0x3f/0x50 [dlm] [ 457.018413] process_recv_sockets+0x3b/0x50 [dlm] [ 457.018415] process_one_work+0x138/0x370 [ 457.018417] worker_thread+0x4d/0x3b0 [ 457.018419] kthread+0x109/0x140 [ 457.018421] ? rescuer_thread+0x320/0x320 [ 457.018422] ? kthread_park+0x60/0x60 [ 457.018424] ret_from_fork+0x25/0x30 Since newsocket created by sock_create_kern sets it's sock by the path: sock_create_kern -> __sock_creat ->pf->create => inet_create -> sock_init_data Then WARN_ON is triggered by "con->sock->ops->accept => inet_accept -> sock_graft", it also means newsock->sk is leaked since sock_graft will replace it with a new sk. To resolve the issue, we need to use sock_create_lite instead of sock_create_kern, like commit 0933a578cd55 ("rds: tcp: use sock_create_lite() to create the accept socket") did. Reported-by: Zhilong Liu Signed-off-by: Guoqing Jiang Signed-off-by: David Teigland --- fs/dlm/lowcomms.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 9382db9..4813d0e 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -729,7 +729,7 @@ static int tcp_accept_from_sock(struct connection *con) mutex_unlock(&connections_lock); memset(&peeraddr, 0, sizeof(peeraddr)); - result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, + result = sock_create_lite(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &newsock); if (result < 0) return -ENOMEM; -- 2.7.4