[PATCH 4.14 193/246] staging: vchiq_core: Fix missing semaphore release in error case

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Wahren <stefan.wahren@xxxxxxxx>

[ Upstream commit 8113b89fc615cfb531df0334fb3a091cf6a45ce0 ]

The bail out branch in case of a invalid tx_pos missed a semaphore
release. Dan Carpenter found this with a static checker.

Fixes: d1eab9dec610 ("staging: vchiq_core: Bail out in case of invalid tx_pos")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -601,6 +601,7 @@ reserve_space(VCHIQ_STATE_T *state, size
 		}
 
 		if (tx_pos == (state->slot_queue_available * VCHIQ_SLOT_SIZE)) {
+			up(&state->slot_available_event);
 			pr_warn("%s: invalid tx_pos: %d\n", __func__, tx_pos);
 			return NULL;
 		}