linux-kernel - [PATCH v3] nvmem: imx-ocotp: fix MAC address byte length

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20250623171003.1875027-1-steffen@innosonix.de>
Date: Mon, 23 Jun 2025 19:09:55 +0200
From: Steffen Bätz <steffen@...osonix.de>
To: 
Cc: Steffen Bätz <steffen@...osonix.de>,
	stable@...r.kernel.org,
	Srinivas Kandagatla <srini@...nel.org>,
	Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>,
	Dmitry Baryshkov <lumag@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v3] nvmem: imx-ocotp: fix MAC address byte length

The commit "13bcd440f2ff nvmem: core: verify cell's raw_len" caused an
extension of the "mac-address" cell from 6 to 8 bytes due to word_size
of 4 bytes.

Thus, the required byte swap for the mac-address of the full buffer length,
caused an trucation of the read mac-address.
>From the original address 70:B3:D5:14:E9:0E to 00:00:70:B3:D5:14

After swapping only the first 6 bytes, the mac-address is correctly passed
to the upper layers.

Fixes: 13bcd440f2ff ("nvmem: core: verify cell's raw_len")
Cc: stable@...r.kernel.org
Signed-off-by: Steffen Bätz <steffen@...osonix.de>
---
v3:
- replace magic number 6 with ETH_ALEN
- Fix misleading indentation and properly group 'mac-address' statements
v2:
- Add Cc: stable@...r.kernel.org as requested by Greg KH's patch bot
 drivers/nvmem/imx-ocotp-ele.c | 6 +++++-
 drivers/nvmem/imx-ocotp.c     | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/imx-ocotp-ele.c b/drivers/nvmem/imx-ocotp-ele.c
index ca6dd71d8a2e..9ef01c91dfa6 100644
--- a/drivers/nvmem/imx-ocotp-ele.c
+++ b/drivers/nvmem/imx-ocotp-ele.c
@@ -12,6 +12,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/if_ether.h>	/* ETH_ALEN */
 
 enum fuse_type {
 	FUSE_FSB = BIT(0),
@@ -118,9 +119,12 @@ static int imx_ocotp_cell_pp(void *context, const char *id, int index,
 	int i;
 
 	/* Deal with some post processing of nvmem cell data */
-	if (id && !strcmp(id, "mac-address"))
+	if (id && !strcmp(id, "mac-address")) {
+		if (bytes > ETH_ALEN)
+			bytes = ETH_ALEN;
 		for (i = 0; i < bytes / 2; i++)
 			swap(buf[i], buf[bytes - i - 1]);
+	}
 
 	return 0;
 }
diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
index 79dd4fda0329..1343cafc37cc 100644
--- a/drivers/nvmem/imx-ocotp.c
+++ b/drivers/nvmem/imx-ocotp.c
@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/if_ether.h>	/* ETH_ALEN */
 
 #define IMX_OCOTP_OFFSET_B0W0		0x400 /* Offset from base address of the
 					       * OTP Bank0 Word0
@@ -227,9 +228,12 @@ static int imx_ocotp_cell_pp(void *context, const char *id, int index,
 	int i;
 
 	/* Deal with some post processing of nvmem cell data */
-	if (id && !strcmp(id, "mac-address"))
+	if (id && !strcmp(id, "mac-address")) {
+		if (bytes > ETH_ALEN)
+			bytes = ETH_ALEN;
 		for (i = 0; i < bytes / 2; i++)
 			swap(buf[i], buf[bytes - i - 1]);
+	}
 
 	return 0;
 }
-- 
2.43.0


-- 


*innosonix GmbH*
Hauptstr. 35
96482 Ahorn
central: +49 9561 7459980
www.innosonix.de <http://www.innosonix.de>

innosonix GmbH
Geschäftsführer: 
Markus Bätz, Steffen Bätz
USt.-IdNr / VAT-Nr.: DE266020313
EORI-Nr.: 
DE240121536680271
HRB 5192 Coburg
WEEE-Reg.-Nr. DE88021242