From 2962aecef2878e2192ac9676700469678507c24d Mon Sep 17 00:00:00 2001 From: Hans-Frieder Vogt Date: Sun, 6 Oct 2013 21:13:35 +0200 Subject: w1 - fix fops in w1_bus_notify Introduce a check to make sure that fops are only called if they have been defined by the slave module. Without this check modules like w1_smem cause a NULL pointer dereference bug. Signed-off by: Hans-Frieder Vogt Acked-by: Evgeniy Polyakov Cc: stable # 3.11+ Signed-off-by: Greg Kroah-Hartman --- drivers/w1/w1.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/w1') diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index c7c64f18773d..0781217d2396 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -613,6 +613,9 @@ static int w1_bus_notify(struct notifier_block *nb, unsigned long action, sl = dev_to_w1_slave(dev); fops = sl->family->fops; + if (!fops) + return 0; + switch (action) { case BUS_NOTIFY_ADD_DEVICE: /* if the family driver needs to initialize something... */ -- cgit v1.2.3 From bc04d76d6942068f75c10790072280b847ec6f1f Mon Sep 17 00:00:00 2001 From: Hans-Frieder Vogt Date: Sun, 6 Oct 2013 21:13:40 +0200 Subject: w1 - call request_module with w1 master mutex unlocked request_module for w1 slave modules needs to be called with the w1 master mutex unlocked. Because w1_attach_slave_device gets always(?) called with mutex locked, we need to temporarily unlock the w1 master mutex for the loading of the w1 slave module. Signed-off by: Hans-Frieder Vogt Acked-by: Evgeniy Polyakov Cc: stable # 3.11+ Signed-off-by: Greg Kroah-Hartman --- drivers/w1/w1.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/w1') diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 0781217d2396..fa932c2f7d97 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -716,7 +716,10 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) atomic_set(&sl->refcnt, 0); init_completion(&sl->released); + /* slave modules need to be loaded in a context with unlocked mutex */ + mutex_unlock(&dev->mutex); request_module("w1-family-0x%0x", rn->family); + mutex_lock(&dev->mutex); spin_lock(&w1_flock); f = w1_family_registered(rn->family); -- cgit v1.2.3