From 779a0f4347a474cf4b503350f3eef682404b6779 Mon Sep 17 00:00:00 2001 From: Andreas Persson Date: Mon, 12 Jul 2021 09:54:52 +0200 Subject: [PATCH] mtd: cfi_cmdset_0002: fix crash when erasing/writing AMD cards commit 2394e628738933aa014093d93093030f6232946d upstream. 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 Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/DB6P189MB05830B3530B8087476C5CFE4C1159@DB6P189MB0583.EURP189.PROD.OUTLOOK.COM Signed-off-by: Greg Kroah-Hartman --- 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 a1f3e1031c3d2..96a27e06401fd 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; }