Re: [PATCH] lib: string_helpers: fix potential snprintf() output truncation
From: James Bottomley
Date: Tue Oct 22 2024 - 10:30:32 EST
On Tue, 2024-10-22 at 15:46 +0200, Rasmus Villemoes wrote:
[...]
> - snprintf(buf, len, "%u%s %s", (u32)size,
> - tmp, unit);
> + if (j)
> + snprintf(buf, len, "%u.%03u %s", (u32)size,
> remainder, unit);
> + else
> + snprintf(buf, len, "%u %s", (u32)size, unit);
> }
> EXPORT_SYMBOL(string_get_size);
Where are you getting this from? The current statement you'd be
replacing is
return snprintf(buf, len, "%u%s%s%s%s", (u32)size, tmp,
(units & STRING_UNITS_NO_SPACE) ? "" : " ",
unit,
(units & STRING_UNITS_NO_BYTES) ? "" : "B");
The use of a tmp buffer prevents that having to be repeated.
If we had a way of specifying "ignore argument" I suppose we could
switch the format string on J and then only have a single statement.
Regards,
James