| commit | c71380ff0b199f1e8be5ca46dd91262f7fbe4cb4 | |
| author | Nikolay Aleksandrov <nikolay@redhat.com> | |
| Thu, 19 Sep 2013 13:02:36 +0000 (19 15:02 +0200) | ||
| committer | David S. Miller <davem@davemloft.net> | |
| Thu, 19 Sep 2013 18:15:53 +0000 (19 14:15 -0400) | ||
| tree | 4d753b6aa3cb50f68f15e85b02cc7f17a443c802 | treesnapshot (tar.gz zip) |
| parent | d0fe8c888b1fd1a2f84b9962cabcb98a70988aec | commitdiff |
netconsole: fix a deadlock with rtnl and netconsole's mutex
This bug was introduced by commit
7a163bfb7ce50895bbe67300ea610d31b9c09230 ("netconsole: avoid a crash with
multiple sysfs writers"). In store_enabled() we have the following
sequence: acquire nt->mutex then rtnl, but in the netconsole netdev
notifier we have rtnl then nt->mutex effectively leading to a deadlock.
The NULL pointer dereference that the above commit tries to fix is
actually due to another bug in netpoll_cleanup(). This is fixed by dropping
the mutex from the netdev notifier as it's already protected by rtnl.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This bug was introduced by commit
7a163bfb7ce50895bbe67300ea610d31b9c09230 ("netconsole: avoid a crash with
multiple sysfs writers"). In store_enabled() we have the following
sequence: acquire nt->mutex then rtnl, but in the netconsole netdev
notifier we have rtnl then nt->mutex effectively leading to a deadlock.
The NULL pointer dereference that the above commit tries to fix is
actually due to another bug in netpoll_cleanup(). This is fixed by dropping
the mutex from the netdev notifier as it's already protected by rtnl.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| drivers/net/netconsole.c | diffblobblamehistory |