[PATCH 5.10.y] mtd: Add check for devm_kcalloc()

[Sasha Levin <sashal@kernel.org>]

From: Jiasheng Jiang <jiashengjiangcool@gmail.com>

[ Upstream commit 2aee30bb10d7bad0a60255059c9ce1b84cf0130e ]

Add a check for devm_kcalloc() to ensure successful allocation.

Fixes: 78c08247b9d3 ("mtd: Support kmsg dumper based on pstore/blk")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mtd/mtdpstore.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mtd/mtdpstore.c b/drivers/mtd/mtdpstore.c
index 5594a22c01375..e86b6c9c44d30 100644
--- a/drivers/mtd/mtdpstore.c
+++ b/drivers/mtd/mtdpstore.c
@@ -423,6 +423,9 @@ static void mtdpstore_notify_add(struct mtd_info *mtd)
 	longcnt = BITS_TO_LONGS(div_u64(mtd->size, mtd->erasesize));
 	cxt->badmap = devm_kcalloc(&mtd->dev, longcnt, sizeof(long), GFP_KERNEL);
 
+	if (!cxt->rmmap || !cxt->usedmap || !cxt->badmap)
+		return;
+
 	cxt->dev.total_size = mtd->size;
 	/* just support dmesg right now */
 	cxt->dev.flags = PSTORE_FLAGS_DMESG;
-- 
2.51.0