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. 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: 13bcd440f2ff ("nvmem: core: verify cell's raw_len") Cc: stable@vger.kernel.org Signed-off-by: Steffen Bätz steffen@innosonix.de Tested-by: Alexander Stein alexander.stein@ew.tq-group.com --- v4: - Adopted the commit message wording recommended by Frank.li@nxp.com to improve clarity. - Simplified byte count determination by using min() instead of an explicit conditional statement. - Kept the Tested-by tag from the previous patch as the change remains trivial but tested. v3: - replace magic number 6 with ETH_ALEN - Fix misleading indentation and properly group 'mac-address' statements v2: - Add Cc: stable@vger.kernel.org as requested by Greg KH's patch bot drivers/nvmem/imx-ocotp-ele.c | 5 ++++- drivers/nvmem/imx-ocotp.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/imx-ocotp-ele.c b/drivers/nvmem/imx-ocotp-ele.c index ca6dd71d8a2e..7807ec0e2d18 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 +119,11 @@ 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; } diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c index 79dd4fda0329..7bf7656d4f96 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 +228,11 @@ 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; }