firewire: cdev: fix potential leak of kernel stack due to uninitialized value

Recent change brings potential leak of value on kernel stack to userspace
due to uninitialized value.

This commit fixes the bug.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 64645b8e74e6 ("firewire: add kernel API to access CYCLE_TIME register")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220512112037.103142-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index c9fe5903725a5f841d5947747badbe616b28e762..9c89f7d53e99db123b4f553e49ab35aa3bfa18fe 100644 (file)
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1211,7 +1211,7 @@ static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg)
        struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2;
        struct fw_card *card = client->device->card;
        struct timespec64 ts = {0, 0};
-       u32 cycle_time;
+       u32 cycle_time = 0;
        int ret = 0;
 
        local_irq_disable();