s390/ap: fix error handling in __verify_queue_reservations()

The AP bus's __verify_queue_reservations function increments the ref count
for the device driver passed in as a parameter, but fails to decrement it
before returning control to the caller. This will prevents any subsequent
removal of the module.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reported-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Fixes: 4f8206b88286 ("s390/ap: driver callback to indicate resource in use")
Link: https://lore.kernel.org/r/20220706222619.602094-1-akrowiak@linux.ibm.com
Cc: stable@vger.kernel.org
[agordeev@linux.ibm.com fixed description, added Fixes and Link]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 5c13d20..0a9045b 100644 (file)
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -1435,7 +1435,7 @@ static int __verify_queue_reservations(struct device_driver *drv, void *data)
        if (ap_drv->in_use) {
                rc = ap_drv->in_use(ap_perms.apm, newaqm);
                if (rc)
-                       return -EBUSY;
+                       rc = -EBUSY;
        }
 
        /* release the driver's module */