| From 8f5e8b01a1da2a207228f2072c934fa5918554b8 Mon Sep 17 00:00:00 2001 |
| From: Joseph Myers <joseph@codesourcery.com> |
| Date: Fri, 4 Dec 2015 20:36:28 +0000 |
| Subject: [PATCH] Fix nan functions handling of payload strings (bug 16961, bug |
| 16962). |
| |
| The nan, nanf and nanl functions handle payload strings by doing e.g.: |
| |
| if (tagp[0] != '\0') |
| { |
| char buf[6 + strlen (tagp)]; |
| sprintf (buf, "NAN(%s)", tagp); |
| return strtod (buf, NULL); |
| } |
| |
| This is an unbounded stack allocation based on the length of the |
| argument. Furthermore, if the argument starts with an n-char-sequence |
| followed by ')', that n-char-sequence is wrongly treated as |
| significant for determining the payload of the resulting NaN, when ISO |
| C says the call should be equivalent to strtod ("NAN", NULL), without |
| being affected by that initial n-char-sequence. This patch fixes both |
| those problems by using the __strtod_nan etc. functions recently |
| factored out of strtod etc. for that purpose, with those functions |
| being exported from libc at version GLIBC_PRIVATE. |
| |
| Tested for x86_64, x86, mips64 and powerpc. |
| |
| [BZ #16961] |
| [BZ #16962] |
| * math/s_nan.c (__nan): Use __strtod_nan instead of constructing a |
| string on the stack for strtod. |
| * math/s_nanf.c (__nanf): Use __strtof_nan instead of constructing |
| a string on the stack for strtof. |
| * math/s_nanl.c (__nanl): Use __strtold_nan instead of |
| constructing a string on the stack for strtold. |
| * stdlib/Versions (libc): Add __strtof_nan, __strtod_nan and |
| __strtold_nan to GLIBC_PRIVATE. |
| * math/test-nan-overflow.c: New file. |
| * math/test-nan-payload.c: Likewise. |
| * math/Makefile (tests): Add test-nan-overflow and |
| test-nan-payload. |
| |
| Upstream-Status: Backport |
| CVE: CVE-2015-9761 patch #2 |
| [Yocto # 8980] |
| |
| https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8f5e8b01a1da2a207228f2072c934fa5918554b8 |
| |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| ChangeLog | 17 +++++++ |
| NEWS | 6 +++ |
| math/Makefile | 3 +- |
| math/s_nan.c | 9 +--- |
| math/s_nanf.c | 9 +--- |
| math/s_nanl.c | 9 +--- |
| math/test-nan-overflow.c | 66 +++++++++++++++++++++++++ |
| math/test-nan-payload.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++ |
| stdlib/Versions | 1 + |
| 9 files changed, 217 insertions(+), 25 deletions(-) |
| create mode 100644 math/test-nan-overflow.c |
| create mode 100644 math/test-nan-payload.c |
| |
| Index: git/ChangeLog |
| =================================================================== |
| --- git.orig/ChangeLog |
| +++ git/ChangeLog |
| @@ -1,3 +1,20 @@ |
| +2015-12-04 Joseph Myers <joseph@codesourcery.com> |
| + |
| + [BZ #16961] |
| + [BZ #16962] |
| + * math/s_nan.c (__nan): Use __strtod_nan instead of constructing a |
| + string on the stack for strtod. |
| + * math/s_nanf.c (__nanf): Use __strtof_nan instead of constructing |
| + a string on the stack for strtof. |
| + * math/s_nanl.c (__nanl): Use __strtold_nan instead of |
| + constructing a string on the stack for strtold. |
| + * stdlib/Versions (libc): Add __strtof_nan, __strtod_nan and |
| + __strtold_nan to GLIBC_PRIVATE. |
| + * math/test-nan-overflow.c: New file. |
| + * math/test-nan-payload.c: Likewise. |
| + * math/Makefile (tests): Add test-nan-overflow and |
| + test-nan-payload. |
| + |
| 2015-11-24 Joseph Myers <joseph@codesourcery.com> |
| |
| * stdlib/strtod_nan.c: New file. |
| Index: git/NEWS |
| =================================================================== |
| --- git.orig/NEWS |
| +++ git/NEWS |
| @@ -99,6 +99,12 @@ Version 2.22 |
| |
| Version 2.21 |
| |
| +Security related changes: |
| + |
| +* The nan, nanf and nanl functions no longer have unbounded stack usage |
| + depending on the length of the string passed as an argument to the |
| + functions. Reported by Joseph Myers. |
| + |
| * The following bugs are resolved with this release: |
| |
| 6652, 10672, 12674, 12847, 12926, 13862, 14132, 14138, 14171, 14498, |
| Index: git/math/Makefile |
| =================================================================== |
| --- git.orig/math/Makefile |
| +++ git/math/Makefile |
| @@ -110,6 +110,7 @@ tests = test-matherr test-fenv atest-exp |
| test-tgmath-ret bug-nextafter bug-nexttoward bug-tgmath1 \ |
| test-tgmath-int test-tgmath2 test-powl tst-CMPLX tst-CMPLX2 test-snan \ |
| test-fenv-tls test-fenv-preserve test-fenv-return test-fenvinline \ |
| + test-nan-overflow test-nan-payload \ |
| $(tests-static) |
| tests-static = test-fpucw-static test-fpucw-ieee-static |
| # We do the `long double' tests only if this data type is available and |
| Index: git/math/s_nan.c |
| =================================================================== |
| --- git.orig/math/s_nan.c |
| +++ git/math/s_nan.c |
| @@ -28,14 +28,7 @@ |
| double |
| __nan (const char *tagp) |
| { |
| - if (tagp[0] != '\0') |
| - { |
| - char buf[6 + strlen (tagp)]; |
| - sprintf (buf, "NAN(%s)", tagp); |
| - return strtod (buf, NULL); |
| - } |
| - |
| - return NAN; |
| + return __strtod_nan (tagp, NULL, 0); |
| } |
| weak_alias (__nan, nan) |
| #ifdef NO_LONG_DOUBLE |
| Index: git/math/s_nanf.c |
| =================================================================== |
| --- git.orig/math/s_nanf.c |
| +++ git/math/s_nanf.c |
| @@ -28,13 +28,6 @@ |
| float |
| __nanf (const char *tagp) |
| { |
| - if (tagp[0] != '\0') |
| - { |
| - char buf[6 + strlen (tagp)]; |
| - sprintf (buf, "NAN(%s)", tagp); |
| - return strtof (buf, NULL); |
| - } |
| - |
| - return NAN; |
| + return __strtof_nan (tagp, NULL, 0); |
| } |
| weak_alias (__nanf, nanf) |
| Index: git/math/s_nanl.c |
| =================================================================== |
| --- git.orig/math/s_nanl.c |
| +++ git/math/s_nanl.c |
| @@ -28,13 +28,6 @@ |
| long double |
| __nanl (const char *tagp) |
| { |
| - if (tagp[0] != '\0') |
| - { |
| - char buf[6 + strlen (tagp)]; |
| - sprintf (buf, "NAN(%s)", tagp); |
| - return strtold (buf, NULL); |
| - } |
| - |
| - return NAN; |
| + return __strtold_nan (tagp, NULL, 0); |
| } |
| weak_alias (__nanl, nanl) |
| Index: git/math/test-nan-overflow.c |
| =================================================================== |
| --- /dev/null |
| +++ git/math/test-nan-overflow.c |
| @@ -0,0 +1,66 @@ |
| +/* Test nan functions stack overflow (bug 16962). |
| + Copyright (C) 2015 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 <math.h> |
| +#include <stdio.h> |
| +#include <string.h> |
| +#include <sys/resource.h> |
| + |
| +#define STACK_LIM 1048576 |
| +#define STRING_SIZE (2 * STACK_LIM) |
| + |
| +static int |
| +do_test (void) |
| +{ |
| + int result = 0; |
| + struct rlimit lim; |
| + getrlimit (RLIMIT_STACK, &lim); |
| + lim.rlim_cur = STACK_LIM; |
| + setrlimit (RLIMIT_STACK, &lim); |
| + char *nanstr = malloc (STRING_SIZE); |
| + if (nanstr == NULL) |
| + { |
| + puts ("malloc failed, cannot test"); |
| + return 77; |
| + } |
| + memset (nanstr, '0', STRING_SIZE - 1); |
| + nanstr[STRING_SIZE - 1] = 0; |
| +#define NAN_TEST(TYPE, FUNC) \ |
| + do \ |
| + { \ |
| + char *volatile p = nanstr; \ |
| + volatile TYPE v = FUNC (p); \ |
| + if (isnan (v)) \ |
| + puts ("PASS: " #FUNC); \ |
| + else \ |
| + { \ |
| + puts ("FAIL: " #FUNC); \ |
| + result = 1; \ |
| + } \ |
| + } \ |
| + while (0) |
| + NAN_TEST (float, nanf); |
| + NAN_TEST (double, nan); |
| +#ifndef NO_LONG_DOUBLE |
| + NAN_TEST (long double, nanl); |
| +#endif |
| + return result; |
| +} |
| + |
| +#define TEST_FUNCTION do_test () |
| +#include "../test-skeleton.c" |
| Index: git/math/test-nan-payload.c |
| =================================================================== |
| --- /dev/null |
| +++ git/math/test-nan-payload.c |
| @@ -0,0 +1,122 @@ |
| +/* Test nan functions payload handling (bug 16961). |
| + Copyright (C) 2015 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 <float.h> |
| +#include <math.h> |
| +#include <stdio.h> |
| +#include <stdlib.h> |
| +#include <string.h> |
| + |
| +/* Avoid built-in functions. */ |
| +#define WRAP_NAN(FUNC, STR) \ |
| + ({ const char *volatile wns = (STR); FUNC (wns); }) |
| +#define WRAP_STRTO(FUNC, STR) \ |
| + ({ const char *volatile wss = (STR); FUNC (wss, NULL); }) |
| + |
| +#define CHECK_IS_NAN(TYPE, A) \ |
| + do \ |
| + { \ |
| + if (isnan (A)) \ |
| + puts ("PASS: " #TYPE " " #A); \ |
| + else \ |
| + { \ |
| + puts ("FAIL: " #TYPE " " #A); \ |
| + result = 1; \ |
| + } \ |
| + } \ |
| + while (0) |
| + |
| +#define CHECK_SAME_NAN(TYPE, A, B) \ |
| + do \ |
| + { \ |
| + if (memcmp (&(A), &(B), sizeof (A)) == 0) \ |
| + puts ("PASS: " #TYPE " " #A " = " #B); \ |
| + else \ |
| + { \ |
| + puts ("FAIL: " #TYPE " " #A " = " #B); \ |
| + result = 1; \ |
| + } \ |
| + } \ |
| + while (0) |
| + |
| +#define CHECK_DIFF_NAN(TYPE, A, B) \ |
| + do \ |
| + { \ |
| + if (memcmp (&(A), &(B), sizeof (A)) != 0) \ |
| + puts ("PASS: " #TYPE " " #A " != " #B); \ |
| + else \ |
| + { \ |
| + puts ("FAIL: " #TYPE " " #A " != " #B); \ |
| + result = 1; \ |
| + } \ |
| + } \ |
| + while (0) |
| + |
| +/* Cannot test payloads by memcmp for formats where NaNs have padding |
| + bits. */ |
| +#define CAN_TEST_EQ(MANT_DIG) ((MANT_DIG) != 64 && (MANT_DIG) != 106) |
| + |
| +#define RUN_TESTS(TYPE, SFUNC, FUNC, MANT_DIG) \ |
| + do \ |
| + { \ |
| + TYPE n123 = WRAP_NAN (FUNC, "123"); \ |
| + CHECK_IS_NAN (TYPE, n123); \ |
| + TYPE s123 = WRAP_STRTO (SFUNC, "NAN(123)"); \ |
| + CHECK_IS_NAN (TYPE, s123); \ |
| + TYPE n456 = WRAP_NAN (FUNC, "456"); \ |
| + CHECK_IS_NAN (TYPE, n456); \ |
| + TYPE s456 = WRAP_STRTO (SFUNC, "NAN(456)"); \ |
| + CHECK_IS_NAN (TYPE, s456); \ |
| + TYPE n123x = WRAP_NAN (FUNC, "123)"); \ |
| + CHECK_IS_NAN (TYPE, n123x); \ |
| + TYPE nemp = WRAP_NAN (FUNC, ""); \ |
| + CHECK_IS_NAN (TYPE, nemp); \ |
| + TYPE semp = WRAP_STRTO (SFUNC, "NAN()"); \ |
| + CHECK_IS_NAN (TYPE, semp); \ |
| + TYPE sx = WRAP_STRTO (SFUNC, "NAN"); \ |
| + CHECK_IS_NAN (TYPE, sx); \ |
| + if (CAN_TEST_EQ (MANT_DIG)) \ |
| + CHECK_SAME_NAN (TYPE, n123, s123); \ |
| + if (CAN_TEST_EQ (MANT_DIG)) \ |
| + CHECK_SAME_NAN (TYPE, n456, s456); \ |
| + if (CAN_TEST_EQ (MANT_DIG)) \ |
| + CHECK_SAME_NAN (TYPE, nemp, semp); \ |
| + if (CAN_TEST_EQ (MANT_DIG)) \ |
| + CHECK_SAME_NAN (TYPE, n123x, sx); \ |
| + CHECK_DIFF_NAN (TYPE, n123, n456); \ |
| + CHECK_DIFF_NAN (TYPE, n123, nemp); \ |
| + CHECK_DIFF_NAN (TYPE, n123, n123x); \ |
| + CHECK_DIFF_NAN (TYPE, n456, nemp); \ |
| + CHECK_DIFF_NAN (TYPE, n456, n123x); \ |
| + } \ |
| + while (0) |
| + |
| +static int |
| +do_test (void) |
| +{ |
| + int result = 0; |
| + RUN_TESTS (float, strtof, nanf, FLT_MANT_DIG); |
| + RUN_TESTS (double, strtod, nan, DBL_MANT_DIG); |
| +#ifndef NO_LONG_DOUBLE |
| + RUN_TESTS (long double, strtold, nanl, LDBL_MANT_DIG); |
| +#endif |
| + return result; |
| +} |
| + |
| +#define TEST_FUNCTION do_test () |
| +#include "../test-skeleton.c" |
| Index: git/stdlib/Versions |
| =================================================================== |
| --- git.orig/stdlib/Versions |
| +++ git/stdlib/Versions |
| @@ -118,5 +118,6 @@ libc { |
| # Used from other libraries |
| __libc_secure_getenv; |
| __call_tls_dtors; |
| + __strtof_nan; __strtod_nan; __strtold_nan; |
| } |
| } |