[PATCH] mailbox: arm_mhuv2: Skip calling kfree() with invalid pointer

It is possible that 'data' passed to kfree() is set to a error value
instead of allocated space. Make sure it doesn't get called with invalid
pointer.

Fixes: 5a6338cce9f4 ("mailbox: arm_mhuv2: Add driver")
Cc: v5.11 <redacted> # v5.11
Reported-by: kernel test robot <redacted>
Reported-by: Dan Carpenter <redacted>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/mailbox/arm_mhuv2.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/arm_mhuv2.c b/drivers/mailbox/arm_mhuv2.c
index cdfb1939fabf..d997f8ebfa98 100644
--- a/drivers/mailbox/arm_mhuv2.c
+++ b/drivers/mailbox/arm_mhuv2.c

@@ -699,7 +699,9 @@ static irqreturn_t mhuv2_receiver_interrupt(int irq, void *arg)
 		ret = IRQ_HANDLED;
 	}
 
-	kfree(data);
+	if (!IS_ERR(data))
+		kfree(data);
+
 	return ret;
 }
 

-- 
2.25.0.rc1.19.g042ed3e048af