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Re: [PATCH] Don't accept exp char without digits in scanf float parsing
- From: Andreas Schwab <schwab at suse dot de>
- To: Roland McGrath <roland at hack dot frob dot com>
- Cc: Rich Felker <dalias at aerifal dot cx>, libc-alpha at sourceware dot org
- Date: Thu, 11 Apr 2013 10:40:00 +0200
- Subject: Re: [PATCH] Don't accept exp char without digits in scanf float parsing
- References: <mvmeheizir3 dot fsf at hawking dot suse dot de> <20130410172642 dot 865F82C07E at topped-with-meat dot com> <20130410175112 dot GE20323 at brightrain dot aerifal dot cx> <20130410182521 dot 058952C07E at topped-with-meat dot com>
This is what I've checked in.
Andreas.
[BZ #13988]
* stdio-common/vfscanf.c (_IO_vfwscanf): When parsing a float
accept exponent character only when digits were seen.
* stdio-common/Makefile (tests): Add bug26.
* stdio-common/bug26.c: New file.
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index f64a8ba..658804b 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -57,7 +57,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
bug19 bug19a tst-popen2 scanf13 scanf14 scanf15 bug20 bug21 bug22 \
scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \
bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \
- bug25 tst-printf-round
+ bug25 tst-printf-round bug26
test-srcs = tst-unbputc tst-printf
diff --git a/stdio-common/bug26.c b/stdio-common/bug26.c
new file mode 100644
index 0000000..a4c6bce
--- /dev/null
+++ b/stdio-common/bug26.c
@@ -0,0 +1,37 @@
+/* Copyright (C) 2013 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <string.h>
+
+int
+main (void)
+{
+ FILE *f;
+ int lost = 0;
+ int c;
+ double d;
+ char s[] = "+.e";
+
+ f = fmemopen (s, strlen (s), "r");
+ /* This should fail to parse a float and leave 'e' in the input. */
+ lost |= (fscanf (f, "%f", &d) != 0);
+ c = fgetc (f);
+ lost |= c != 'e';
+ puts (lost ? "Test FAILED!" : "Test succeeded.");
+ return lost;
+}
diff --git a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c
index 9b5c4a9..82f7eee 100644
--- a/stdio-common/vfscanf.c
+++ b/stdio-common/vfscanf.c
@@ -222,7 +222,7 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
/* Errno of last failed inchar call. */
int inchar_errno = 0;
/* Status for reading F-P nums. */
- char got_dot, got_e, negative;
+ char got_digit, got_dot, got_e, negative;
/* If a [...] is a [^...]. */
CHAR_T not_in;
#define exp_char not_in
@@ -1845,7 +1845,7 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
if (__builtin_expect (c == EOF, 0))
input_error ();
- got_dot = got_e = 0;
+ got_digit = got_dot = got_e = 0;
/* Check for a sign. */
if (c == L_('-') || c == L_('+'))
@@ -1971,13 +1971,19 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
while (1)
{
if (ISDIGIT (c))
- ADDW (c);
+ {
+ ADDW (c);
+ got_digit = 1;
+ }
else if (!got_e && (flags & HEXA_FLOAT) && ISXDIGIT (c))
- ADDW (c);
+ {
+ ADDW (c);
+ got_digit = 1;
+ }
else if (got_e && wp[wpsize - 1] == exp_char
&& (c == L_('-') || c == L_('+')))
ADDW (c);
- else if (wpsize > 0 && !got_e
+ else if (got_digit && !got_e
&& (CHAR_T) TOLOWER (c) == exp_char)
{
ADDW (exp_char);
--
1.8.2.1
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."