Commit 2aa4ad62 authored by Steffen Bätz's avatar Steffen Bätz Committed by Greg Kroah-Hartman
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nvmem: imx-ocotp: fix MAC address byte length 



The commit "13bcd440 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. This led to a required byte swap of the full buffer length,
which caused truncation of the mac-address when read.

Previously, the mac-address was incorrectly truncated from
70:B3:D5:14:E9:0E to 00:00:70:B3:D5:14.

Fix the issue by swapping only the first 6 bytes to correctly pass the
mac-address to the upper layers.

Fixes: 13bcd440 ("nvmem: core: verify cell's raw_len")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarSteffen Bätz <steffen@innosonix.de>
Tested-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: default avatarSrinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250712181729.6495-3-srini@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ae68ad3d

drivers/nvmem/imx-ocotp-ele.c

+4 −1
Original line number Diff line number Diff line
@@ -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 +119,11 @@ 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")) {

		bytes = min(bytes, ETH_ALEN);

		for (i = 0; i < bytes / 2; i++)

			swap(buf[i], buf[bytes - i - 1]);

	}



	return 0;

}

drivers/nvmem/imx-ocotp.c

+4 −1
Original line number Diff line number Diff line
@@ -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 +228,11 @@ 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")) {

		bytes = min(bytes, ETH_ALEN);

		for (i = 0; i < bytes / 2; i++)

			swap(buf[i], buf[bytes - i - 1]);

	}



	return 0;

}