ubi-utils: FIX DIVISION BY ZERO in ubinize.c

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@gmail.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

diff --git a/ubi-utils/ubinize.c b/ubi-utils/ubinize.c
index ac8c1e53dfe6d88aaffb389000f07f1fe02659bd..9c950b1ebb1672046e44be91a27692cf838d3b3e 100644 (file)
--- 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);