[3.13.y.z extended stable] Patch "lockd: ensure we tear down any live sockets when socket creation fails during lockd_up" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    lockd: ensure we tear down any live sockets when socket creation fails during lockd_up

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 84b017e1e37c0185fe1b817d703c717dffb66530 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton at redhat.com>
Date: Tue, 25 Mar 2014 11:55:26 -0700
Subject: lockd: ensure we tear down any live sockets when socket creation
 fails during lockd_up

commit 679b033df48422191c4cac52b610d9980e019f9b upstream.

We had a Fedora ABRT report with a stack trace like this:

kernel BUG at net/sunrpc/svc.c:550!
invalid opcode: 0000 [#1] SMP
[...]
CPU: 2 PID: 913 Comm: rpc.nfsd Not tainted 3.13.6-200.fc20.x86_64 #1
Hardware name: Hewlett-Packard HP ProBook 4740s/1846, BIOS 68IRR Ver. F.40 01/29/2013
task: ffff880146b00000 ti: ffff88003f9b8000 task.ti: ffff88003f9b8000
RIP: 0010:[<ffffffffa0305fa8>]  [<ffffffffa0305fa8>] svc_destroy+0x128/0x130 [sunrpc]
RSP: 0018:ffff88003f9b9de0  EFLAGS: 00010206
RAX: ffff88003f829628 RBX: ffff88003f829600 RCX: 00000000000041ee
RDX: 0000000000000000 RSI: 0000000000000286 RDI: 0000000000000286
RBP: ffff88003f9b9de8 R08: 0000000000017360 R09: ffff88014fa97360
R10: ffffffff8114ce57 R11: ffffea00051c9c00 R12: ffff88003f829600
R13: 00000000ffffff9e R14: ffffffff81cc7cc0 R15: 0000000000000000
FS:  00007f4fde284840(0000) GS:ffff88014fa80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4fdf5192f8 CR3: 00000000a569a000 CR4: 00000000001407e0
Stack:
 ffff88003f792300 ffff88003f9b9e18 ffffffffa02de02a 0000000000000000
 ffffffff81cc7cc0 ffff88003f9cb000 0000000000000008 ffff88003f9b9e60
 ffffffffa033bb35 ffffffff8131c86c ffff88003f9cb000 ffff8800a5715008
Call Trace:
 [<ffffffffa02de02a>] lockd_up+0xaa/0x330 [lockd]
 [<ffffffffa033bb35>] nfsd_svc+0x1b5/0x2f0 [nfsd]
 [<ffffffff8131c86c>] ? simple_strtoull+0x2c/0x50
 [<ffffffffa033c630>] ? write_pool_threads+0x280/0x280 [nfsd]
 [<ffffffffa033c6bb>] write_threads+0x8b/0xf0 [nfsd]
 [<ffffffff8114efa4>] ? __get_free_pages+0x14/0x50
 [<ffffffff8114eff6>] ? get_zeroed_page+0x16/0x20
 [<ffffffff811dec51>] ? simple_transaction_get+0xb1/0xd0
 [<ffffffffa033c098>] nfsctl_transaction_write+0x48/0x80 [nfsd]
 [<ffffffff811b8b34>] vfs_write+0xb4/0x1f0
 [<ffffffff811c3f99>] ? putname+0x29/0x40
 [<ffffffff811b9569>] SyS_write+0x49/0xa0
 [<ffffffff810fc2a6>] ? __audit_syscall_exit+0x1f6/0x2a0
 [<ffffffff816962e9>] system_call_fastpath+0x16/0x1b
Code: 31 c0 e8 82 db 37 e1 e9 2a ff ff ff 48 8b 07 8b 57 14 48 c7 c7 d5 c6 31 a0 48 8b 70 20 31 c0 e8 65 db 37 e1 e9 f4 fe ff ff 0f 0b <0f> 0b 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55
RIP  [<ffffffffa0305fa8>] svc_destroy+0x128/0x130 [sunrpc]
 RSP <ffff88003f9b9de0>

Evidently, we created some lockd sockets and then failed to create
others. make_socks then returned an error and we tried to tear down the
svc, but svc->sv_permsocks was not empty so we ended up tripping over
the BUG() in svc_destroy().

Fix this by ensuring that we tear down any live sockets we created when
socket creation is going to return an error.

Fixes: 786185b5f8abefa (SUNRPC: move per-net operations from...)
Reported-by: Raphos <raphoszap at laposte.net>
Signed-off-by: Jeff Layton <jlayton at redhat.com>
Reviewed-by: Stanislav Kinsbursky <skinsbursky at parallels.com>
Signed-off-by: J. Bruce Fields <bfields at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/lockd/svc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 10d6c41..6bf06a0 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -235,6 +235,7 @@ out_err:
 	if (warned++ == 0)
 		printk(KERN_WARNING
 			"lockd_up: makesock failed, error=%d\n", err);
+	svc_shutdown_net(serv, net);
 	return err;
 }

--
1.9.1