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| author | David Woodhouse <dwmw2@infradead.org> | 2011-10-24 21:25:21 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-25 19:22:23 -0400 |
| commit | 08613e4626c06ca408fc55071f6aedee36986a87 (patch) | |
| tree | 4251c4fa37ed1571a61505a70fed4dffdaaece82 /net/caif/caif_dev.c | |
| parent | 59fdaca9a4497ada47328d7b4b406b98a6f1c1a6 (diff) | |
| download | linux-08613e4626c06ca408fc55071f6aedee36986a87.tar.gz linux-08613e4626c06ca408fc55071f6aedee36986a87.tar.bz2 linux-08613e4626c06ca408fc55071f6aedee36986a87.zip | |
caif: Fix BUG() with network namespaces
The caif code will register its own pernet_operations, and then register
a netdevice_notifier. Each time the netdevice_notifier is triggered,
it'll do some stuff... including a lookup of its own pernet stuff with
net_generic().
If the net_generic() call ever returns NULL, the caif code will BUG().
That doesn't seem *so* unreasonable, I suppose — it does seem like it
should never happen.
However, it *does* happen. When we clone a network namespace,
setup_net() runs through all the pernet_operations one at a time. It
gets to loopback before it gets to caif. And loopback_net_init()
registers a netdevice... while caif hasn't been initialised. So the caif
netdevice notifier triggers, and immediately goes BUG().
We could imagine a complex and overengineered solution to this generic
class of problems, but this patch takes the simple approach. It just
makes caif_device_notify() *not* go looking for its pernet data
structures if the device it's being notified about isn't a caif device
in the first place.
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/caif/caif_dev.c')
| -rw-r--r-- | net/caif/caif_dev.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c index 7f9ac0742d19..47fc8f3a47cf 100644 --- a/net/caif/caif_dev.c +++ b/net/caif/caif_dev.c @@ -212,8 +212,7 @@ static int caif_device_notify(struct notifier_block *me, unsigned long what, enum cfcnfg_phy_preference pref; enum cfcnfg_phy_type phy_type; struct cfcnfg *cfg; - struct caif_device_entry_list *caifdevs = - caif_device_list(dev_net(dev)); + struct caif_device_entry_list *caifdevs; if (dev->type != ARPHRD_CAIF) return 0; @@ -222,6 +221,8 @@ static int caif_device_notify(struct notifier_block *me, unsigned long what, if (cfg == NULL) return 0; + caifdevs = caif_device_list(dev_net(dev)); + switch (what) { case NETDEV_REGISTER: caifd = caif_device_alloc(dev); |