[PATCH mtd-utils] ubi-utils: FIX DIVISION BY ZERO in ubinize.c

[Zhihao Cheng]

在 2024/12/25 3:40, Anton Moryakov 写道:
> Report of the static analyzer:
> Variable vi->alignment, whose possible value set allows a zero value at ubinize.c:375, is used as a denominator at ubinize.c:410.
> 
> If you look at the code more closely, it will be clear that the vi->alignment parameter is obtained from an external file passed as a command line argument.
> 
> A check was also performed if you pass a test.ini file of the following type to the input:
> 
> [jffs2-volume]
> mode=ubi
> image=../jffs2.img
> vol_id=1
> vol_size=30MiB
> vol_type=dynamic
> vol_name=jffs2_volume
> vol_flags=autoresize
> vol_alignment=0
> 
> and execute the command:
> 
> ./ubinize -o ubi.img -p 16KiB -m 512 -s 256 test.ini
> 
> we will get the result:
> 
> Floating point exception (core dumped)
> 
> Corrections explained:
> Updated the validation logic for vi->alignment:
> - Replaced the check for negative alignment (`vi->id < 0`) with a more comprehensive check for non-positive alignment (`vi->alignment <= 0`).
> - Updated the corresponding error message to reflect the requirement for a positive volume alignment.
> This ensures more robust validation and improves error clarity when invalid alignment values are encountered.
> 
> Triggers found by static analyzer Svace.
> 
> Signed-off-by: Anton Moryakov <ant.v.moryakov at gmail.com>
> 
> ---
>   ubi-utils/ubinize.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 

Reviewed-by: Zhihao Cheng <chengzhihao1 at huawei.com>
> diff --git a/ubi-utils/ubinize.c b/ubi-utils/ubinize.c
> index ac8c1e5..9c950b1 100644
> --- a/ubi-utils/ubinize.c
> +++ b/ubi-utils/ubinize.c
> @@ -375,8 +375,8 @@ static int read_section(const struct ubigen_info *ui, const char *sname,
>   	vi->alignment = iniparser_getint(args.dict, buf, -1);
>   	if (vi->alignment == -1)
>   		vi->alignment = 1;
> -	else if (vi->id < 0)
> -		return errmsg("negative volume alignment %d in section \"%s\"",
> +	else if (vi->alignment <= 0)
> +		return errmsg("not positive volume alignment %d in section \"%s\"",
>   			      vi->alignment, sname);
>   
>   	verbose(args.verbose, "volume alignment: %d", vi->alignment);
>