Re: [PATCH] nvmem: layouts: u-boot-env: handle quotes in MAC post process

From: Srinivas Kandagatla

Date: Sun Sep 20 2026 - 12:45:10 EST




On 8/20/26 10:17 PM, Michael C. Pratt wrote:
> Although it is not common, some board models from some vendors have
> a MAC address stored in u-boot environment as a quoted form, e.g.
>
> ethaddr="AA:BB:CC:DD:EE:FF"
>
> This is acceptable formatting for a u-boot environment variable, however,
> it makes parsing MACs in post processing more variable and currently fails.
>
> Add a second attempt when initial processing of the MAC address fails,
> by allowing a longer length and try parsing again if it seems to be quoted.
>
> The mac_pton() function has strict behavior on the length and location
> of delimiters for each octet and that each digit is hexadecimal,
> so attempting different offsets of the same string is not problematic.
>
> Signed-off-by: Michael C. Pratt <mcpratt@xxxxx>
> ---
> drivers/nvmem/layouts/u-boot-env.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)

this patch looks stale as
commit 45cb0223740b863089ce3cc523155cf7a55e1479
Author: Tomasz Maciej Nowak <tmn505@xxxxxxxxx>
Date: Sat May 30 21:53:33 2026 +0100

nvmem: layouts: u-boot-env: check earlier for ethaddr length

already has some changes in this area,


--srini
>
> diff --git a/drivers/nvmem/layouts/u-boot-env.c b/drivers/nvmem/layouts/u-boot-env.c
> index f27f387bb52a..ff71c3c25d42 100644
> --- a/drivers/nvmem/layouts/u-boot-env.c
> +++ b/drivers/nvmem/layouts/u-boot-env.c
> @@ -38,11 +38,15 @@ static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, i
> {
> u8 mac[ETH_ALEN];
>
> + /* Handle quotation which increases length by 2 bytes if present. */
> if (bytes != MAC_ADDR_STR_LEN)
> - return -EINVAL;
> + if (bytes != MAC_ADDR_STR_LEN + 2 && !(*(char *)buf == '"' || *(char *)buf == '\''))
> + return -EINVAL;
>
> + /* Handle quotation which offsets data by 1 byte if present. */
> if (!mac_pton(buf, mac))
> - return -EINVAL;
> + if (!mac_pton(buf + 1, mac))
> + return -EINVAL;
>
> if (index)
> eth_addr_add(mac, index);