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 <hfvogt@gmx.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index c7c64f1..0781217 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -613,6 +613,9 @@
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... */