[PATCH 3.13 036/163] lockd: fix rpcbind crash on lockd startup failure

From: Kamal Mostafa
Date: Thu Oct 09 2014 - 17:37:04 EST -stable review patch. If anyone has any objections, please let me know.


From: "J. Bruce Fields" <bfields@xxxxxxxxxx>

commit 7c17705e77b12b20fb8afb7c1b15dcdb126c0c12 upstream.

Nikita Yuschenko reported that booting a kernel with init=/bin/sh and
then nfs mounting without portmap or rpcbind running using a busybox
mount resulted in:

# mount -t nfs /mnt
svc: failed to register lockdv1 RPC service (errno 111).
lockd_up: makesock failed, error=-111
Unable to handle kernel paging request for data at address 0x00000030
Faulting instruction address: 0xc055e65c
Oops: Kernel access of bad area, sig: 11 [#1]
Modules linked in:
CPU: 0 PID: 1338 Comm: mount Not tainted 3.10.44.cge #117
task: cf29cea0 ti: cf35c000 task.ti: cf35c000
NIP: c055e65c LR: c0566490 CTR: c055e648
REGS: cf35dad0 TRAP: 0300 Not tainted (3.10.44.cge)
MSR: 00029000 <CE,EE,ME> CR: 22442488 XER: 20000000
DEAR: 00000030, ESR: 00000000

GPR00: c05606f4 cf35db80 cf29cea0 cf0ded80 cf0dedb8 00000001 1dec3086
GPR08: 00000000 c07b1640 00000007 1dec3086 22442482 100b9758 00000000
GPR16: 00000000 000186a5 00000000 00000000 100c3018 bfa46edc 100b0000
GPR24: cf386ae0 c07834f0 00000000 c0565f88 00000001 cf0dedb8 00000000
NIP [c055e65c] call_start+0x14/0x34
LR [c0566490] __rpc_execute+0x70/0x250
Call Trace:
[cf35db80] [00000080] 0x80 (unreliable)
[cf35dbb0] [c05606f4] rpc_run_task+0x9c/0xc4
[cf35dbc0] [c0560840] rpc_call_sync+0x50/0xb8
[cf35dbf0] [c056ee90] rpcb_register_call+0x54/0x84
[cf35dc10] [c056f24c] rpcb_register+0xf8/0x10c
[cf35dc70] [c0569e18] svc_unregister.isra.23+0x100/0x108
[cf35dc90] [c0569e38] svc_rpcb_cleanup+0x18/0x30
[cf35dca0] [c0198c5c] lockd_up+0x1dc/0x2e0
[cf35dcd0] [c0195348] nlmclnt_init+0x2c/0xc8
[cf35dcf0] [c015bb5c] nfs_start_lockd+0x98/0xec
[cf35dd20] [c015ce6c] nfs_create_server+0x1e8/0x3f4
[cf35dd90] [c0171590] nfs3_create_server+0x10/0x44
[cf35dda0] [c016528c] nfs_try_mount+0x158/0x1e4
[cf35de20] [c01670d0] nfs_fs_mount+0x434/0x8c8
[cf35de70] [c00cd3bc] mount_fs+0x20/0xbc
[cf35de90] [c00e4f88] vfs_kern_mount+0x50/0x104
[cf35dec0] [c00e6e0c] do_mount+0x1d0/0x8e0
[cf35df10] [c00e75ac] SyS_mount+0x90/0xd0
[cf35df40] [c000ccf4] ret_from_syscall+0x0/0x3c

The addition of svc_shutdown_net() resulted in two calls to
svc_rpcb_cleanup(); the second is no longer necessary and crashes when
it calls rpcb_register_call with clnt=NULL.

Reported-by: Nikita Yushchenko <nyushchenko@xxxxxxxxxxxxx>
Fixes: 679b033df484 "lockd: ensure we tear down any live sockets when socket creation fails during lockd_up"
Acked-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
fs/lockd/svc.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 6bf06a0..223e1cb 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -253,13 +253,11 @@ static int lockd_up_net(struct svc_serv *serv, struct net *net)

error = make_socks(serv, net);
if (error < 0)
- goto err_socks;
+ goto err_bind;
dprintk("lockd_up_net: per-net data created; net=%p\n", net);
return 0;

- svc_rpcb_cleanup(serv, net);
return error;

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