[PULL 07/20] hw/net/can/flexcan: Fix out-of-bounds access in flexcan_mx_rx()

From: Bernhard Beschow <[email protected]>

Require `last_not_free_to_receive_mbid >= 0` before indexing `mbs[]`.
This prevents a possible `-1` array index and fixes Coverity CID
1662790.

Reported-by: Peter Maydell <[email protected]>
Signed-off-by: Bernhard Beschow <[email protected]>
Tested-by: Pavel Pisa <[email protected]>
Reviewed-by: Peter Maydell <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
---
 hw/net/can/flexcan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/net/can/flexcan.c b/hw/net/can/flexcan.c
index 3a97edf7a4d..dd92a383373 100644
--- a/hw/net/can/flexcan.c
+++ b/hw/net/can/flexcan.c
@@ -1075,7 +1075,7 @@ static enum FlexcanRx flexcan_mb_rx(FlexcanState *s, const qemu_can_frame *buf)
         }
     }
 
-    if (last_not_free_to_receive_mbid >= -1) {
+    if (last_not_free_to_receive_mbid >= 0) {
         if (last_not_free_to_receive_locked) {
             /*
              * copy to temporary mailbox (SMB)
-- 
2.43.0