[U-Boot] [PATCH v3] sandbox: Use memmove() to move overlapping regions

[Alexander Graf]

On 11/13/2018 11:55 PM, Simon Glass wrote:
> The use of strcpy() to remove characters at the start of a string is safe
> in U-Boot, since we know the implementation. But in os.c we are using the
> C library's strcpy() function, where this behaviour is not permitted.
>
> Update the code to use memmove() instead.
>
> Reported-by: Coverity (CID: 173279)
> Signed-off-by: Simon Glass <sjg at chromium.org>

Reviewed-by: Alexander Graf <agraf at suse.de>

Alex

> ---
>
> Changes in v3:
> - Fix commit message to say memmove() instead of memcpy()
>
> Changes in v2:
> - Also remove the leading / from the "/spl" path
> - Correct the string calculation
>
>   arch/sandbox/cpu/os.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
> index 07e46471fe5..04669bfc177 100644
> --- a/arch/sandbox/cpu/os.c
> +++ b/arch/sandbox/cpu/os.c
> @@ -641,9 +641,10 @@ int os_find_u_boot(char *fname, int maxlen)
>   	}
>   
>   	/* Look for 'u-boot' in the parent directory of spl/ */
> -	p = strstr(fname, "/spl/");
> +	p = strstr(fname, "spl/");
>   	if (p) {
> -		strcpy(p, p + 4);
> +		/* Remove the "spl" characters */
> +		memmove(p, p + 4, strlen(p + 4) + 1);
>   		fd = os_open(fname, O_RDONLY);
>   		if (fd >= 0) {
>   			close(fd);