releases/5.11.3/scsi-ufs-fix-a-possible-null-pointer-issue.patch

From 6ed3c0573ed03c66494713fd6a9db5f35cd25963 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Wed, 13 Jan 2021 19:13:27 -0800
Subject: scsi: ufs: Fix a possible NULL pointer issue

From: Can Guo <cang@codeaurora.org>

[ Upstream commit fb7afe24ba1b7e27483be7d2ac3ed002e67eecd5 ]

During system resume/suspend, hba could be NULL. In this case, do not touch
eh_sem.

Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM events and async scan")
Link: https://lore.kernel.org/r/1610594010-7254-2-git-send-email-cang@codeaurora.org
Acked-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/ufs/ufshcd.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index fb32d122f2e38..728168cd18f55 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -94,6 +94,8 @@
 		       16, 4, buf, __len, false);                        \
 } while (0)
 
+static bool early_suspend;
+
 int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len,
 		     const char *prefix)
 {
@@ -8939,8 +8941,14 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
 	int ret = 0;
 	ktime_t start = ktime_get();
 
+	if (!hba) {
+		early_suspend = true;
+		return 0;
+	}
+
 	down(&hba->eh_sem);
-	if (!hba || !hba->is_powered)
+
+	if (!hba->is_powered)
 		return 0;
 
 	if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
@@ -8989,9 +8997,12 @@ int ufshcd_system_resume(struct ufs_hba *hba)
 	int ret = 0;
 	ktime_t start = ktime_get();
 
-	if (!hba) {
-		up(&hba->eh_sem);
+	if (!hba)
 		return -EINVAL;
+
+	if (unlikely(early_suspend)) {
+		early_suspend = false;
+		down(&hba->eh_sem);
 	}
 
 	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
-- 
2.27.0