[PATCH 5.18 223/231] s390/ap: fix error handling in __verify_queue_reservations()

From: Greg Kroah-Hartman
Date: Tue Jul 19 2022 - 09:11:47 EST


From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>

commit 2f23256c0ea20627c91ea2d468cda945f68c3395 upstream.

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@xxxxxxxxxxxxx>
Reported-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Fixes: 4f8206b88286 ("s390/ap: driver callback to indicate resource in use")
Link: https://lore.kernel.org/r/20220706222619.602094-1-akrowiak@xxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
[agordeev@xxxxxxxxxxxxx fixed description, added Fixes and Link]
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/crypto/ap_bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -1410,7 +1410,7 @@ static int __verify_queue_reservations(s
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 */