diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-03-26 21:12:00 +0900 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2026-05-05 10:19:15 +0200 |
| commit | 71876dffab295b6e25d4209f0424da8fc5020e12 (patch) | |
| tree | 27539ebf92cb3939e6bf2752d276cb744d746034 /lib | |
| parent | b66cb4f156fe47f52065e70eb1b2f12ccd0c2884 (diff) | |
| download | linux-next-history-71876dffab295b6e25d4209f0424da8fc5020e12.tar.gz | |
lib/vsprintf: Fix to check field_width and precision
Check the field_width and presition correctly. Previously it depends
on the bitfield conversion from int to check out-of-range error.
However, commit 938df695e98d ("vsprintf: associate the format state
with the format pointer") changed those fields to int.
We need to check the out-of-range correctly without bitfield
conversion.
Fixes: 938df695e98d ("vsprintf: associate the format state with the format pointer")
Reported-by: David Laight <david.laight.linux@gmail.com>
Closes: https://lore.kernel.org/all/20260318151250.40fef0ab@pumpkin/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/177452712047.197965.16376597502504928495.stgit@devnote2
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/vsprintf.c | 36 |
1 files changed, 14 insertions, 22 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 9f359b31c8d1c..3c76cc5c7f9ce 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2640,6 +2640,18 @@ static unsigned char spec_flag(unsigned char c) return (c < sizeof(spec_flag_array)) ? spec_flag_array[c] : 0; } +static void set_field_width(struct printf_spec *spec, int width) +{ + spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); + WARN_ONCE(spec->field_width != width, "field width %d out of range", width); +} + +static void set_precision(struct printf_spec *spec, int prec) +{ + spec->precision = clamp(prec, 0, PRECISION_MAX); + WARN_ONCE(spec->precision < prec, "precision %d too large", prec); +} + /* * Helper function to decode printf style format. * Each call decode a token from the format and return the @@ -2710,7 +2722,7 @@ struct fmt format_decode(struct fmt fmt, struct printf_spec *spec) spec->field_width = -1; if (isdigit(*fmt.str)) - spec->field_width = skip_atoi(&fmt.str); + set_field_width(spec, skip_atoi(&fmt.str)); else if (unlikely(*fmt.str == '*')) { /* it's the next argument */ fmt.state = FORMAT_STATE_WIDTH; @@ -2724,9 +2736,7 @@ precision: if (unlikely(*fmt.str == '.')) { fmt.str++; if (isdigit(*fmt.str)) { - spec->precision = skip_atoi(&fmt.str); - if (spec->precision < 0) - spec->precision = 0; + set_precision(spec, skip_atoi(&fmt.str)); } else if (*fmt.str == '*') { /* it's the next argument */ fmt.state = FORMAT_STATE_PRECISION; @@ -2799,24 +2809,6 @@ qualifier: return fmt; } -static void -set_field_width(struct printf_spec *spec, int width) -{ - spec->field_width = width; - if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { - spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); - } -} - -static void -set_precision(struct printf_spec *spec, int prec) -{ - spec->precision = prec; - if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { - spec->precision = clamp(prec, 0, PRECISION_MAX); - } -} - /* * Turn a 1/2/4-byte value into a 64-bit one for printing: truncate * as necessary and deal with signedness. |