From 2394e628738933aa014093d93093030f6232946d Mon Sep 17 00:00:00 2001
From: Andreas Persson <andreasp56@outlook.com>
Date: Mon, 12 Jul 2021 09:54:52 +0200
Subject: [PATCH] mtd: cfi_cmdset_0002: fix crash when erasing/writing AMD cards
Git-commit: 2394e628738933aa014093d93093030f6232946d
Patch-mainline: v5.14-rc7
References: git-fixes
Erasing an AMD linear flash card (AM29F016D) crashes after the first
sector has been erased. Likewise, writing to it crashes after two bytes
have been written. The reason is a missing check for a null pointer -
the cmdset_priv field is not set for this type of card.
Fixes: 4844ef80305d ("mtd: cfi_cmdset_0002: Add support for polling status register")
Signed-off-by: Andreas Persson <andreasp56@outlook.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/DB6P189MB05830B3530B8087476C5CFE4C1159@DB6P189MB0583.EURP189.PROD.OUTLOOK.COM
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/mtd/chips/cfi_cmdset_0002.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 3097e93787f7..a761134fd3be 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -119,7 +119,7 @@ static int cfi_use_status_reg(struct cfi_private *cfi)
struct cfi_pri_amdstd *extp = cfi->cmdset_priv;
u8 poll_mask = CFI_POLL_STATUS_REG | CFI_POLL_DQ;
- return extp->MinorVersion >= '5' &&
+ return extp && extp->MinorVersion >= '5' &&
(extp->SoftwareFeatures & poll_mask) == CFI_POLL_STATUS_REG;
}
--
2.26.2