[NET]: Fix race in dev_close(). (Bug 9750)

!MAILaRCHIVE_VOTE_RePLACE
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: <git-commits-head@...>
Date: Friday, February 15, 2008 - 6:01 pm

Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d8b2a4...
Commit:     d8b2a4d21e0b37b9669b202867bfef19f68f786a
Parent:     b318e0e4ef4e85812c25afa19f75addccc834cd4
Author:     Matti Linnanvuori <mattilinnanvuori@yahoo.com>
AuthorDate: Tue Feb 12 23:10:11 2008 -0800
Committer:  David S. Miller <davem@davemloft.net>
CommitDate: Tue Feb 12 23:11:16 2008 -0800

    [NET]: Fix race in dev_close(). (Bug 9750)
    
    There is a race in Linux kernel file net/core/dev.c, function dev_close.
    The function calls function dev_deactivate, which calls function
    dev_watchdog_down that deletes the watchdog timer. However, after that, a
    driver can call netif_carrier_ok, which calls function
    __netdev_watchdog_up that can add the watchdog timer again. Function
    unregister_netdevice calls function dev_shutdown that traps the bug
    !timer_pending(&dev->watchdog_timer). Moving dev_deactivate after
    netif_running() has been cleared prevents function netif_carrier_on
    from calling __netdev_watchdog_up and adding the watchdog timer again.
    
    Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/core/dev.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 9549417..6cfc123 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1071,8 +1071,6 @@ int dev_close(struct net_device *dev)
 	 */
 	call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
 
-	dev_deactivate(dev);
-
 	clear_bit(__LINK_STATE_START, &dev->state);
 
 	/* Synchronize to scheduled poll. We cannot touch poll list,
@@ -1083,6 +1081,8 @@ int dev_close(struct net_device *dev)
 	 */
 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
 
+	dev_deactivate(dev);
+
 	/*
 	 *	Call the device specific close. This cannot fail.
 	 *	Only if device is UP
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[NET]: Fix race in dev_close(). (Bug 9750), Linux Kernel Mailing List..., (Fri Feb 15, 6:01 pm)