Re: sunrpc/clnt.c: BUG kmalloc-256 (Not tainted): Poison overwritten
From: Myklebust, Trond
Date: Sun Jul 14 2013 - 23:01:58 EST
On Sun, 2013-07-14 at 10:02 +0200, Toralf FÃrster wrote:
> This bisected commit produces at a 32 bit user mode linux guest the attached BUG :
>
> commit eeee245268c951262b861bc1be4e9dc812352499
> Author: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> Date: Wed Jul 10 15:33:01 2013 -0400
>
> SUNRPC: Fix a deadlock in rpc_client_register()
>
> Commit 384816051ca9125cd54750e59c780c2a2655fa4f (SUNRPC: fix races on
> PipeFS MOUNT notifications) introduces a regression when we call
> rpc_setup_pipedir() with RPCSEC_GSS as the auth flavour.
>
> By calling rpcauth_create() while holding the sn->pipefs_sb_lock, we
> end up deadlocking in gss_pipes_dentries_create_net().
> Fix is to register the client and release the mutex before calling
> rpcauth_create().
>
> Reported-by: Weston Andros Adamson <dros@xxxxxxxxxx>
> Tested-by: Weston Andros Adamson <dros@xxxxxxxxxx>
> Cc: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # : 3848160: SUNRPC: fix races on PipeFS MOUNT
> Cc: <stable@xxxxxxxxxxxxxxx> # : e73f4cc: SUNRPC: split client creation
> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
>
>
>
>
>
>
> 2013-07-13T22:09:07.000+02:00 trinity sm-notify[1042]: Version 1.2.6 starting
> 2013-07-13T22:09:07.000+02:00 trinity sm-notify[1042]: Backgrounding to notify hosts...
> 2013-07-13T22:09:07.000+02:00 trinity sm-notify[1043]: Running as root. chown /var/lib/nfs to choose different user
> 2013-07-13T22:09:10.000+02:00 trinity mount[1047]: mount to NFS server 'n22stab4' failed: No route to host, retrying
> 2013-07-13T22:09:11.000+02:00 trinity dhcpcd[971]: eth0: sending IPv6 Router Solicitation
> 2013-07-13T22:09:11.000+02:00 trinity dhcpcd[971]: eth0: no IPv6 Routers available
> 2013-07-13T22:09:13.000+02:00 trinity mount[1048]: mount to NFS server 'n22stab4' failed: No route to host, retrying
> 2013-07-13T22:09:13.647+02:00 trinity kernel: =============================================================================
> 2013-07-13T22:09:13.647+02:00 trinity kernel: BUG kmalloc-256 (Not tainted): Poison overwritten
> 2013-07-13T22:09:13.647+02:00 trinity kernel: -----------------------------------------------------------------------------
> 2013-07-13T22:09:13.647+02:00 trinity kernel:
> 2013-07-13T22:09:13.647+02:00 trinity kernel: Disabling lock debugging due to kernel taint
> 2013-07-13T22:09:13.647+02:00 trinity kernel: INFO: 0x49b1ed18-0x49b1ed1b. First byte 0x74 instead of 0x6b
> 2013-07-13T22:09:13.647+02:00 trinity kernel: INFO: Allocated in rpc_new_client+0x81/0x3a0 age=300 cpu=0 pid=1049
> 2013-07-13T22:09:13.647+02:00 trinity kernel: INFO: Freed in rpc_new_client+0x35a/0x3a0 age=300 cpu=0 pid=1049
> 2013-07-13T22:09:13.647+02:00 trinity kernel: INFO: Slab 0x0b87bac0 objects=13 used=13 fp=0x (null) flags=0x0080
> 2013-07-13T22:09:13.647+02:00 trinity kernel: INFO: Object 0x49b1ed10 @offset=3344 fp=0x49b1ee40
> 2013-07-13T22:09:13.653+02:00 trinity kernel:
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Bytes b4 49b1ed00: f6 03 00 00 bd 94 ff ff 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed10: 6b 6b 6b 6b 6b 6b 6b 6b 74 3a 85 49 6b 6b 6b 6b kkkkkkkkt:.Ikkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed20: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed30: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed40: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed50: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed60: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed70: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.653+02:00 trinity kernel: Object 49b1ed80: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1ed90: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1eda0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1edb0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1edc0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1edd0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1ede0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1edf0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Object 49b1ee00: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Redzone 49b1ee10: bb bb bb bb ....
> 2013-07-13T22:09:13.660+02:00 trinity kernel: Padding 49b1ee38: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
> 2013-07-13T22:09:13.665+02:00 trinity kernel: CPU: 0 PID: 1030 Comm: rpc.idmapd Tainted: G B 3.10.0-09292-g621fa28 #1
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957a1c 48957a48 080f78b0 084ab0f8 49b1ed10 00000d10 49b1ee40 0b87bac0
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 49b1ed18 00000004 49b1ed1b 48957a80 080f7e88 084ab1d8 49b1ed18 49b1ed1b
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 00000074 0000006b 0000005a 49b1ed10 0b87bac0 49849c00 49849c00 49b1ed10 489579f0: [<0805fb1f>] show_stack+0xcf/0x100
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957a14: [<0840345d>] dump_stack+0x26/0x28
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957a24: [<080f78b0>] print_trailer+0xe0/0xf0
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957a4c: [<080f7e88>] check_bytes_and_report+0xa8/0x100
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957a84: [<080f7fb8>] check_object+0xd8/0x210
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957ac0: [<08401a84>] alloc_debug_processing+0x7d/0x10e
> 2013-07-13T22:09:13.665+02:00 trinity kernel: 48957ae4: [<084023cd>] __slab_alloc.constprop.74+0x356/0x3a4
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957b70: [<080fae85>] __kmalloc_track_caller+0x85/0x160
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957b98: [<082c90f3>] __kmalloc_reserve.isra.47+0x33/0x90
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957bc0: [<082c9276>] __alloc_skb+0x76/0x210
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957bec: [<082c65a1>] sock_alloc_send_pskb+0xb1/0x320
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957c34: [<082c683e>] sock_alloc_send_skb+0x2e/0x30
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957c50: [<08344831>] unix_stream_sendmsg+0x161/0x3b0
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957ca8: [<082c23be>] sock_sendmsg+0x7e/0xa0
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957d6c: [<082c378a>] SyS_sendto+0xea/0x120
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957e44: [<082c37f6>] SyS_send+0x36/0x40
> 2013-07-13T22:09:13.673+02:00 trinity kernel: 48957e64: [<082c4247>] SyS_socketcall+0x167/0x300
> 2013-07-13T22:09:13.678+02:00 trinity kernel: 48957eac: [<080618e2>] handle_syscall+0x82/0xb0
> 2013-07-13T22:09:13.678+02:00 trinity kernel: 48957ef4: [<08073d6d>] userspace+0x46d/0x590
> 2013-07-13T22:09:13.678+02:00 trinity kernel: 48957fec: [<0805e65c>] fork_handler+0x6c/0x70
> 2013-07-13T22:09:13.678+02:00 trinity kernel: 48957ffc: [<00000000>] 0x0
> 2013-07-13T22:09:13.678+02:00 trinity kernel:
> 2013-07-13T22:09:13.678+02:00 trinity kernel: FIX kmalloc-256: Restoring 0x49b1ed18-0x49b1ed1b=0x6b
> 2013-07-13T22:09:13.678+02:00 trinity kernel:
> 2013-07-13T22:09:13.678+02:00 trinity kernel: FIX kmalloc-256: Marking all objects used
> 2013-07-13T22:09:13.000+02:00 trinity mount[1049]: mount to NFS server 'n22stab4' failed: No route to host, retrying
> 2013-07-13T22:09:16.000+02:00 trinity mount[1048]: mount to NFS server 'n22stab4' failed: No route to host, retrying
> 2013-07-13T22:09:16.648+02:00 trinity kernel: =============================================================================
> 2013-07-13T22:09:16.648+02:00 trinity kernel: BUG kmalloc-256 (Tainted: G B ): Poison overwritten
> 2013-07-13T22:09:16.648+02:00 trinity kernel: -----------------------------------------------------------------------------
> 2013-07-13T22:09:16.648+02:00 trinity kernel:
Does the attached patch fix the problem?
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
From 80b5a058b1eed5c267110df7e041d0302eaff81c Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Date: Sun, 14 Jul 2013 22:57:50 -0400
Subject: [PATCH] SUNRPC: Fix another issue with rpc_client_register()
Fix the error pathway if rpcauth_create() fails.
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
net/sunrpc/clnt.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index aa40156..4a35e1d 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -313,6 +313,7 @@ static int rpc_client_register(const struct rpc_create_args *args,
return 0;
err_auth:
pipefs_sb = rpc_get_sb_net(net);
+ rpc_unregister_client(clnt);
__rpc_clnt_remove_pipedir(clnt);
out:
if (pipefs_sb)
--
1.8.3.1