From: frank.blaschka@de.ibm.com
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org,
Ursula Braun <ursula.braun@de.ibm.com>
Subject: [patch 06/10] [PATCH] qeth: suspicious rcu_dereference_check in recovery
Date: Tue, 20 Dec 2011 09:56:32 +0100 [thread overview]
Message-ID: <20111220085736.122805720@de.ibm.com> (raw)
In-Reply-To: 20111220085626.924756639@de.ibm.com
[-- Attachment #1: 606-qeth-rtnl-lock.diff --]
[-- Type: text/plain, Size: 2297 bytes --]
From: Ursula Braun <ursula.braun@de.ibm.com>
qeth layer3 recovery invokes its set_multicast_list function, which
invokes function __vlan_find_dev_deep requiring rcu_read_lock or
rtnl lock. This causes kernel messages:
kernel: [ INFO: suspicious rcu_dereference_check() usage. ]
kernel: ---------------------------------------------------
kernel: net/8021q/vlan_core.c:70 invoked rcu_dereference_check() without protection!
kernel: stack backtrace:
kernel: CPU: 0 Not tainted 3.1.0 #9
kernel: Process qeth_recover (pid: 2078, task: 000000007e584680, ksp: 000000007e3e3930)
kernel: 000000007e3e3d08 000000007e3e3c88 0000000000000002 0000000000000000
kernel: 000000007e3e3d28 000000007e3e3ca0 000000007e3e3ca0 00000000005e77ce
kernel: 0000000000000000 0000000000000001 ffffffffffffffff 0000000000000001
kernel: 000000000000000d 000000000000000c 000000007e3e3cf0 0000000000000000
kernel: 0000000000000000 0000000000100a18 000000007e3e3c88 000000007e3e3cc8
kernel: Call Trace:
kernel: ([<0000000000100926>] show_trace+0xee/0x144)
kernel: [<00000000005d395c>] __vlan_find_dev_deep+0xb0/0x108
kernel: [<00000000004acd3a>] qeth_l3_set_multicast_list+0x976/0xe38
kernel: [<00000000004ae0f4>] __qeth_l3_set_online+0x75c/0x1498
kernel: [<00000000004aefec>] qeth_l3_recover+0xc4/0x1d0
kernel: [<0000000000185372>] kthread+0xa6/0xb0
kernel: [<00000000005ed4c6>] kernel_thread_starter+0x6/0xc
kernel: [<00000000005ed4c0>] kernel_thread_starter+0x0/0xc
The patch makes sure the rtnl lock is held once qeth recovery invokes
its set_multicast_list function.
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
---
drivers/s390/net/qeth_l3_main.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -3492,14 +3492,13 @@ contin:
else
netif_carrier_off(card->dev);
if (recover_flag == CARD_STATE_RECOVER) {
+ rtnl_lock();
if (recovery_mode)
__qeth_l3_open(card->dev);
- else {
- rtnl_lock();
+ else
dev_open(card->dev);
- rtnl_unlock();
- }
qeth_l3_set_multicast_list(card->dev);
+ rtnl_unlock();
}
/* let user_space know that device is online */
kobject_uevent(&gdev->dev.kobj, KOBJ_CHANGE);
next prev parent reply other threads:[~2011-12-20 8:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-20 8:56 [patch 00/10] s390: network driver features and fixes for net-next frank.blaschka
2011-12-20 8:56 ` [patch 01/10] [PATCH] af_iucv: support ancillary data with HS transport frank.blaschka
2011-12-20 8:56 ` [patch 02/10] [PATCH] af_iucv: accelerate close for " frank.blaschka
2011-12-20 8:56 ` [patch 03/10] [PATCH] af_iucv: release reference to HS device frank.blaschka
2011-12-20 8:56 ` [patch 04/10] [PATCH] af_iucv: remove unused timer infrastructure frank.blaschka
2011-12-20 8:56 ` [patch 05/10] [PATCH] af_iucv: get rid of state IUCV_SEVERED frank.blaschka
2011-12-20 8:56 ` frank.blaschka [this message]
2011-12-20 8:56 ` [patch 07/10] [PATCH] qeth: forbid recovery during shutdown frank.blaschka
2011-12-20 8:56 ` [patch 08/10] [PATCH] netiucv: allow multiple interfaces to same peer frank.blaschka
2011-12-20 8:56 ` [patch 09/10] [PATCH] qeth: improve recovery during resource shortage frank.blaschka
2011-12-20 8:56 ` [patch 10/10] [PATCH] qeth: recovery through asynchronous delivery frank.blaschka
2011-12-20 19:05 ` [patch 00/10] s390: network driver features and fixes for net-next David Miller
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