From: Mauro Carvalho Chehab Date: Thu, 14 Oct 2010 15:23:56 +0000 (-0300) Subject: [media] ir: avoid race conditions at device disconnect X-Git-Tag: firefly_0821_release~7613^2~3587^2~203 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b4d752b308493b08b51ea04361848ef63d0cad42;p=firefly-linux-kernel-4.4.55.git [media] ir: avoid race conditions at device disconnect It is possible that, while ir_unregister_class() is handling, some application could try to access the sysfs nodes, causing an OOPS. Reviewed-by: Jarod Wilson Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/IR/ir-sysfs.c b/drivers/media/IR/ir-sysfs.c index be09d1995b41..186807aa226d 100644 --- a/drivers/media/IR/ir-sysfs.c +++ b/drivers/media/IR/ir-sysfs.c @@ -68,6 +68,10 @@ static ssize_t show_protocols(struct device *d, char *tmp = buf; int i; + /* Device is being removed */ + if (!ir_dev) + return -EINVAL; + if (ir_dev->props && ir_dev->props->driver_type == RC_DRIVER_SCANCODE) { enabled = ir_dev->rc_tab.ir_type; allowed = ir_dev->props->allowed_protos; @@ -123,6 +127,10 @@ static ssize_t store_protocols(struct device *d, int rc, i, count = 0; unsigned long flags; + /* Device is being removed */ + if (!ir_dev) + return -EINVAL; + if (ir_dev->props && ir_dev->props->driver_type == RC_DRIVER_SCANCODE) type = ir_dev->rc_tab.ir_type; else if (ir_dev->raw) @@ -310,6 +318,7 @@ void ir_unregister_class(struct input_dev *input_dev) { struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); + input_set_drvdata(input_dev, NULL); clear_bit(ir_dev->devno, &ir_core_dev_number); input_unregister_device(input_dev); device_del(&ir_dev->dev);