From 28ac8e03c43dfc6a703aa420d18222540b801120 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Thu, 15 Apr 2021 12:06:54 +0100
Subject: [PATCH] dmaengine: idxd: Fix potential null dereference on pointer status
Git-commit: 28ac8e03c43dfc6a703aa420d18222540b801120
Patch-mainline: v5.13-rc1
References: git-fixes

There are calls to idxd_cmd_exec that pass a null status pointer however
a recent commit has added an assignment to *status that can end up
with a null pointer dereference.  The function expects a null status
pointer sometimes as there is a later assignment to *status where
status is first null checked.  Fix the issue by null checking status
before making the assignment.

Addresses-coverity: ("Explicit null dereferenced")
Fixes: 89e3becd8f82 ("dmaengine: idxd: check device state before issue command")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20210415110654.1941580-1-colin.king@canonical.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/dma/idxd/device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 84a6ea60ecf0..90b875b15c13 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -445,7 +445,8 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
 
 	if (idxd_device_is_halted(idxd)) {
 		dev_warn(&idxd->pdev->dev, "Device is HALTED!\n");
-		*status = IDXD_CMDSTS_HW_ERR;
+		if (status)
+			*status = IDXD_CMDSTS_HW_ERR;
 		return;
 	}
 
-- 
2.26.2