[B.A.T.M.A.N.] [PATCH maint] batman-adv: fix interface clean up on error

[B.A.T.M.A.N.] [PATCH maint] batman-adv: fix interface clean up on error

[Antonio Quartulli]

When enabling an hard_iface for the first time, the
hard_iface->soft_iface member is initialised with the newly
created soft_iface.
However, in case of error during the activation procedure
this member has to be set to NULL again, otherwise the
hard_iface will result busy and will not be possible to use
it anymore

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
---

it is possible to easily reproduce the bug without the patch:
$ batctl if add eth0
$ brctl addbr br0
$ brctl addif br0 bat0
$ batctl if add br0
Error - can't write to file '/sys/class/net/br0/batman_adv/mesh_iface': Device or resource busy
$ batctl if add br0
$
[no error anymore because br0 is already "associated" to bat0 and check at
sysfs.c:575 evaluates to true]



with the patch:
$ batctl if add eth0
$ brctl addbr br0
$ brctl addif br0 bat0
$ batctl if add br0
Error - can't write to file '/sys/class/net/br0/batman_adv/mesh_iface': Device or resource busy
$ batctl if add br0
Error - can't write to file '/sys/class/net/br0/batman_adv/mesh_iface': Device or resource busy
$

Cheers,


 hard-interface.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hard-interface.c b/hard-interface.c
index 368219e..70bc9ce 100644
--- a/hard-interface.c
+++ b/hard-interface.c
@@ -402,6 +402,7 @@ out:
 	return 0;
 
 err_dev:
+	hard_iface->soft_iface = NULL;
 	dev_put(soft_iface);
 err:
 	batadv_hardif_free_ref(hard_iface);
-- 
1.8.1.5

Re: [B.A.T.M.A.N.] [PATCH maint] batman-adv: fix interface clean up on error

[Antonio Quartulli]

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On Sun, Mar 24, 2013 at 01:00:31 +0100, Antonio Quartulli wrote:
> When enabling an hard_iface for the first time, the
> hard_iface->soft_iface member is initialised with the newly
> created soft_iface.
> However, in case of error during the activation procedure
> this member has to be set to NULL again, otherwise the
> hard_iface will result busy and will not be possible to use
> it anymore
> 

I forgot to mention that this problem was already observed in the past during
previous tests of the rtnl API:

Reported-by: Marek Lindner <lindner_marek@yahoo.de>

Thanks!

> Signed-off-by: Antonio Quartulli <ordex@autistici.org>

-- 
Antonio Quartulli

..each of us alone is worth nothing..
Ernesto "Che" Guevara

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