[PATCH] mmc: dw_mmc: Fix potential null pointer risk

From: Aleksandr Mishin <amishin@t-argos.ru>
To: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Aleksandr Mishin <amishin@t-argos.ru>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Wen Zhiwei <wenzhiwei@kylinos.cn>, <linux-mmc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <lvc-project@linuxtesting.org>
Subject: [PATCH] mmc: dw_mmc: Fix potential null pointer risk
Date: Thu, 7 Mar 2024 11:51:35 +0300	[thread overview]
Message-ID: <20240307085135.16245-1-amishin@t-argos.ru> (raw)

In dw_mci_runtime_resume() 'host->slot' could be null, but check is not cover all corresponding code.
Fix this bug by changing check place.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 4a835afd808a (mmc: dw_mmc: Fix potential null pointer risk)
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
---
 drivers/mmc/host/dw_mmc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 829af2c98a44..a4f124452abc 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -3570,8 +3570,10 @@ int dw_mci_runtime_resume(struct device *dev)
 		   DW_MCI_ERROR_FLAGS);
 	mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
 
+	if (!host->slot)
+		goto err;
 
-	if (host->slot && host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
+	if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
 		dw_mci_set_ios(host->slot->mmc, &host->slot->mmc->ios);
 
 	/* Force setup bus to guarantee available clock output */
-- 
2.30.2

