linux-kernel - [PATCH] mtd: rawnand: use kcalloc() instead of kzalloc()

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Message-Id: <20250222-mtd-nand-kzalloc-v1-1-fbb41db6fd8e@ethancedwards.com>
Date: Sat, 22 Feb 2025 14:19:43 -0500
From: Ethan Carter Edwards <ethan@...ancedwards.com>
To: Miquel Raynal <miquel.raynal@...tlin.com>, 
 Richard Weinberger <richard@....at>, Vignesh Raghavendra <vigneshr@...com>
Cc: linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 linux-hardening@...r.kernel.org, 
 Ethan Carter Edwards <ethan@...ancedwards.com>
Subject: [PATCH] mtd: rawnand: use kcalloc() instead of kzalloc()

We are trying to get rid of all multiplications from allocation
functions to prevent integer overflows[1]. Here the multiplication is
obviously safe, but using kcalloc() is more appropriate and improves
readability. This patch has no effect on runtime behavior.

Link: https://github.com/KSPP/linux/issues/162 [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Signed-off-by: Ethan Carter Edwards <ethan@...ancedwards.com>
---
 drivers/mtd/nand/raw/nand_base.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 53e16d39af4bf95c16505e0b528da1f3ba832010..13e4060bd1b6a1a360d430260b881edc8a3abeff 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -1833,7 +1833,7 @@ int nand_readid_op(struct nand_chip *chip, u8 addr, void *buf,
 
 		/* READ_ID data bytes are received twice in NV-DDR mode */
 		if (len && nand_interface_is_nvddr(conf)) {
-			ddrbuf = kzalloc(len * 2, GFP_KERNEL);
+			ddrbuf = kcalloc(2, len, GFP_KERNEL);
 			if (!ddrbuf)
 				return -ENOMEM;
 
@@ -2203,7 +2203,7 @@ int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
 		 * twice.
 		 */
 		if (force_8bit && nand_interface_is_nvddr(conf)) {
-			ddrbuf = kzalloc(len * 2, GFP_KERNEL);
+			ddrbuf = kcalloc(2, len, GFP_KERNEL);
 			if (!ddrbuf)
 				return -ENOMEM;
 

---
base-commit: d4b0fd87ff0d4338b259dc79b2b3c6f7e70e8afa
change-id: 20250222-mtd-nand-kzalloc-29cc08138b24

Best regards,
-- 
Ethan Carter Edwards <ethan@...ancedwards.com>