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[3.8.y.z,extended,stable] Patch "dummy: fix oops when loading the dummy failed" has been added to staging queue

Message ID 1374798250-6794-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa July 26, 2013, 12:24 a.m. UTC
This is a note to let you know that I have just added a patch titled

    dummy: fix oops when loading the dummy failed

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.6.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From d57471fdc24980c56584202bd840577cbdfa40ec Mon Sep 17 00:00:00 2001
From: dingtianhong <dingtianhong@huawei.com>
Date: Thu, 11 Jul 2013 19:04:02 +0800
Subject: dummy: fix oops when loading the dummy failed

[ Upstream commit 2c8a01894a12665d8059fad8f0a293c98a264121 ]

We rename the dummy in modprobe.conf like this:

install dummy0 /sbin/modprobe -o dummy0 --ignore-install dummy
install dummy1 /sbin/modprobe -o dummy1 --ignore-install dummy

We got oops when we run the command:

modprobe dummy0
modprobe dummy1

------------[ cut here ]------------

[ 3302.187584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 3302.195411] IP: [<ffffffff813fe62a>] __rtnl_link_unregister+0x9a/0xd0
[ 3302.201844] PGD 85c94a067 PUD 8517bd067 PMD 0
[ 3302.206305] Oops: 0002 [#1] SMP
[ 3302.299737] task: ffff88105ccea300 ti: ffff880eba4a0000 task.ti: ffff880eba4a0000
[ 3302.307186] RIP: 0010:[<ffffffff813fe62a>]  [<ffffffff813fe62a>] __rtnl_link_unregister+0x9a/0xd0
[ 3302.316044] RSP: 0018:ffff880eba4a1dd8  EFLAGS: 00010246
[ 3302.321332] RAX: 0000000000000000 RBX: ffffffff81a9d738 RCX: 0000000000000002
[ 3302.328436] RDX: 0000000000000000 RSI: ffffffffa04d602c RDI: ffff880eba4a1dd8
[ 3302.335541] RBP: ffff880eba4a1e18 R08: dead000000200200 R09: dead000000100100
[ 3302.342644] R10: 0000000000000080 R11: 0000000000000003 R12: ffffffff81a9d788
[ 3302.349748] R13: ffffffffa04d7020 R14: ffffffff81a9d670 R15: ffff880eba4a1dd8
[ 3302.364910] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3302.370630] CR2: 0000000000000008 CR3: 000000085e15e000 CR4: 00000000000427e0
[ 3302.377734] DR0: 0000000000000003 DR1: 00000000000000b0 DR2: 0000000000000001
[ 3302.384838] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 3302.391940] Stack:
[ 3302.393944]  ffff880eba4a1dd8 ffff880eba4a1dd8 ffff880eba4a1e18 ffffffffa04d70c0
[ 3302.401350]  00000000ffffffef ffffffffa01a8000 0000000000000000 ffffffff816111c8
[ 3302.408758]  ffff880eba4a1e48 ffffffffa01a80be ffff880eba4a1e48 ffffffffa04d70c0
[ 3302.416164] Call Trace:
[ 3302.418605]  [<ffffffffa01a8000>] ? 0xffffffffa01a7fff
[ 3302.423727]  [<ffffffffa01a80be>] dummy_init_module+0xbe/0x1000 [dummy0]
[ 3302.430405]  [<ffffffffa01a8000>] ? 0xffffffffa01a7fff
[ 3302.435535]  [<ffffffff81000322>] do_one_initcall+0x152/0x1b0
[ 3302.441263]  [<ffffffff810ab24b>] do_init_module+0x7b/0x200
[ 3302.446824]  [<ffffffff810ad3d2>] load_module+0x4e2/0x530
[ 3302.452215]  [<ffffffff8127ae40>] ? ddebug_dyndbg_boot_param_cb+0x60/0x60
[ 3302.458979]  [<ffffffff810ad5f1>] SyS_init_module+0xd1/0x130
[ 3302.464627]  [<ffffffff814b9652>] system_call_fastpath+0x16/0x1b
[ 3302.490090] RIP  [<ffffffff813fe62a>] __rtnl_link_unregister+0x9a/0xd0
[ 3302.496607]  RSP <ffff880eba4a1dd8>
[ 3302.500084] CR2: 0000000000000008
[ 3302.503466] ---[ end trace 8342d49cd49f78ed ]---

The reason is that when loading dummy, if __rtnl_link_register() return failed,
the init_module should return and avoid take the wrong path.

Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/net/dummy.c | 4 ++++
 1 file changed, 4 insertions(+)

--
1.8.1.2
diff mbox

Patch

diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index c260af5..1f3ff91 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -175,6 +175,8 @@  static int __init dummy_init_module(void)

 	rtnl_lock();
 	err = __rtnl_link_register(&dummy_link_ops);
+	if (err < 0)
+		goto out;

 	for (i = 0; i < numdummies && !err; i++) {
 		err = dummy_init_one();
@@ -182,6 +184,8 @@  static int __init dummy_init_module(void)
 	}
 	if (err < 0)
 		__rtnl_link_unregister(&dummy_link_ops);
+
+out:
 	rtnl_unlock();

 	return err;