Re: [PATCH] tools/power/acpi: Replace strcpy/strcat with snprintf in osunixdir.c

[Rafael J. Wysocki]

On Sun, Feb 1, 2026 at 7:17 PM Sumeet Pawnikar <sumeet4linux@xxxxxxxxx> wrote:
>
> Replace unsafe strcpy() and strcat() calls with snprintf() in
> osunixdir.c to prevent potential buffer overflow vulnerabilities
> when constructing file paths.
>
> The snprintf() function performs automatic bounds checking to ensure
> the destination buffer is not overflowed.
>
> No functional change.
>
> Signed-off-by: Sumeet Pawnikar <sumeet4linux@xxxxxxxxx>

The ACPI tools come from ACPICA, so if you want to make changes to
them, you need to do that in upstream ACPICA.

Refer to Documentation/driver-api/acpi/linuxized-acpica.rst for more
information.

Thanks!

> ---
>  .../power/acpi/os_specific/service_layers/osunixdir.c  | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/tools/power/acpi/os_specific/service_layers/osunixdir.c b/tools/power/acpi/os_specific/service_layers/osunixdir.c
> index b9bb83116549..5dc960c6b376 100644
> --- a/tools/power/acpi/os_specific/service_layers/osunixdir.c
> +++ b/tools/power/acpi/os_specific/service_layers/osunixdir.c
> @@ -113,9 +113,8 @@ char *acpi_os_get_next_filename(void *dir_handle)
>                                 return (NULL);
>                         }
>
> -                       strcpy(temp_str, external_info->dir_pathname);
> -                       strcat(temp_str, "/");
> -                       strcat(temp_str, dir_entry->d_name);
> +                       snprintf(temp_str, str_len, "%s/%s",
> +                                external_info->dir_pathname, dir_entry->d_name);
>
>                         err = stat(temp_str, &temp_stat);
>                         if (err == -1) {
> @@ -137,8 +136,9 @@ char *acpi_os_get_next_filename(void *dir_handle)
>
>                                 /* copy to a temp buffer because dir_entry struct is on the stack */
>
> -                               strcpy(external_info->temp_buffer,
> -                                      dir_entry->d_name);
> +                               snprintf(external_info->temp_buffer,
> +                                        sizeof(external_info->temp_buffer),
> +                                        "%s", dir_entry->d_name);
>                                 return (external_info->temp_buffer);
>                         }
>                 }
> --
> 2.43.0
>
>