diff options
| -rw-r--r-- | stdio-common/Makefile | 2 | ||||
| -rw-r--r-- | stdio-common/tst-grouping3.c | 54 | ||||
| -rw-r--r-- | stdio-common/vfprintf-process-arg.c | 22 |
3 files changed, 73 insertions, 5 deletions
diff --git a/stdio-common/Makefile b/stdio-common/Makefile index 34fdd6d..652d9e5 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -196,6 +196,7 @@ tests := \ tst-gets \ tst-grouping \ tst-grouping2 \ + tst-grouping3 \ tst-long-dbl-fphex \ tst-memstream-string \ tst-obprintf \ @@ -340,6 +341,7 @@ $(objpfx)tst-sscanf.out: $(gen-locales) $(objpfx)tst-swprintf.out: $(gen-locales) $(objpfx)tst-vfprintf-mbs-prec.out: $(gen-locales) $(objpfx)tst-vfprintf-width-i18n.out: $(gen-locales) +$(objpfx)tst-grouping3.out: $(gen-locales) endif tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace \ diff --git a/stdio-common/tst-grouping3.c b/stdio-common/tst-grouping3.c new file mode 100644 index 0000000..e9e3921 --- /dev/null +++ b/stdio-common/tst-grouping3.c @@ -0,0 +1,54 @@ +/* Test printf with grouping and padding (bug 30068) + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <locale.h> +#include <stdio.h> +#include <support/check.h> +#include <support/support.h> + +static int +do_test (void) +{ + char buf[80]; + + xsetlocale (LC_NUMERIC, "de_DE.UTF-8"); + + /* The format string has the following conversion specifier: + ' - Use thousands grouping. + + - The result of a signed conversion shall begin with a sign. + - - Left justified. + 13 - Minimum 13 bytes of width. + 9 - Minimum 9 digits of precision. + + In bug 30068 the grouping characters were not accounted for in + the width, and were added after the fact resulting in a 15-byte + output instead of a 13-byte output. The two additional bytes + come from the locale-specific thousands separator. This increase + in size could result in a buffer overflow if a reasonable caller + calculated the size of the expected buffer using nl_langinfo to + determine the sie of THOUSEP in bytes. + + This bug is distinct from bug 23432 which has to do with the + minimum precision calculation (digit based). */ + sprintf (buf, "%+-'13.9d", 1234567); + TEST_COMPARE_STRING (buf, "+001.234.567 "); + + return 0; +} + +#include <support/test-driver.c> diff --git a/stdio-common/vfprintf-process-arg.c b/stdio-common/vfprintf-process-arg.c index 24c9125..8c0fcbc 100644 --- a/stdio-common/vfprintf-process-arg.c +++ b/stdio-common/vfprintf-process-arg.c @@ -186,11 +186,17 @@ LABEL (unsigned_number): /* Unsigned number of base BASE. */ bool octal_marker = (prec <= number_length && number.word != 0 && alt && base == 8); - prec = MAX (0, prec - (workend - string)); + /* At this point prec_inc is the additional bytes required for the + specificed precision. It is 0 if the precision would not have + required additional bytes i.e. the number of input digits is more + than the precision. It is greater than zero if the precision is + more than the number of digits without grouping (precision only + considers digits). */ + unsigned int prec_inc = MAX (0, prec - (workend - string)); if (!left) { - width -= number_length + prec; + width -= number_length + prec_inc; if (number.word != 0 && alt && (base == 16 || base == 2)) /* Account for 0X, 0x, 0B or 0b hex or binary marker. */ @@ -221,7 +227,7 @@ LABEL (unsigned_number): /* Unsigned number of base BASE. */ Xprintf_buffer_putc (buf, spec); } - width += prec; + width += prec_inc; Xprintf_buffer_pad (buf, L_('0'), width); if (octal_marker) @@ -237,6 +243,8 @@ LABEL (unsigned_number): /* Unsigned number of base BASE. */ } else { + /* Perform left justification adjustments. */ + if (is_negative) { Xprintf_buffer_putc (buf, L_('-')); @@ -263,9 +271,13 @@ LABEL (unsigned_number): /* Unsigned number of base BASE. */ if (octal_marker) --width; - width -= workend - string + prec; + /* Adjust the width by subtracting the number of bytes + required to represent the number with grouping characters + (NUMBER_LENGTH) and any additional bytes required for + precision. */ + width -= number_length + prec_inc; - Xprintf_buffer_pad (buf, L_('0'), prec); + Xprintf_buffer_pad (buf, L_('0'), prec_inc); if (octal_marker) Xprintf_buffer_putc (buf, L_('0')); |