diff options
| -rw-r--r-- | libc/Android.mk | 2 | ||||
| -rw-r--r-- | libc/include/string.h | 62 | ||||
| -rw-r--r-- | libc/string/__strlcat_chk.c | 55 | ||||
| -rw-r--r-- | libc/string/__strlcpy_chk.c | 55 |
4 files changed, 174 insertions, 0 deletions
diff --git a/libc/Android.mk b/libc/Android.mk index f90520e..06d36fe 100644 --- a/libc/Android.mk +++ b/libc/Android.mk @@ -214,6 +214,8 @@ libc_common_src_files := \ string/__memset_chk.c \ string/__strcat_chk.c \ string/__strcpy_chk.c \ + string/__strlcat_chk.c \ + string/__strlcpy_chk.c \ string/__strncat_chk.c \ string/__strncpy_chk.c \ wchar/wcpcpy.c \ diff --git a/libc/include/string.h b/libc/include/string.h index e1718e9..b8f60e4 100644 --- a/libc/include/string.h +++ b/libc/include/string.h @@ -122,6 +122,68 @@ void *memset (void *s, int c, size_t n) { return __builtin___memset_chk(s, c, n, __builtin_object_size (s, 0)); } +extern size_t strlcpy_real(char *, const char *, size_t) + __asm__(__USER_LABEL_PREFIX__ "strlcpy"); +extern void __strlcpy_error() + __attribute__((error ("strlcpy called with size bigger than buffer"))); +extern size_t __strlcpy_chk(char *, const char *, size_t, size_t); + +__BIONIC_FORTIFY_INLINE +size_t strlcpy(char *dest, const char *src, size_t size) { + size_t bos = __builtin_object_size(dest, 0); + + // Compiler doesn't know destination size. Don't call __strlcpy_chk + if (bos == (size_t) -1) { + return strlcpy_real(dest, src, size); + } + + // Compiler can prove, at compile time, that the passed in size + // is always <= the actual object size. Don't call __strlcpy_chk + if (__builtin_constant_p(size) && (size <= bos)) { + return strlcpy_real(dest, src, size); + } + + // Compiler can prove, at compile time, that the passed in size + // is always > the actual object size. Force a compiler error. + if (__builtin_constant_p(size) && (size > bos)) { + __strlcpy_error(); + } + + return __strlcpy_chk(dest, src, size, bos); +} + +extern size_t strlcat_real(char *, const char *, size_t) + __asm__(__USER_LABEL_PREFIX__ "strlcat"); +extern void __strlcat_error() + __attribute__((error ("strlcat called with size bigger than buffer"))); +extern size_t __strlcat_chk(char *, const char *, size_t, size_t); + + +__BIONIC_FORTIFY_INLINE +size_t strlcat(char *dest, const char *src, size_t size) { + size_t bos = __builtin_object_size(dest, 0); + + // Compiler doesn't know destination size. Don't call __strlcat_chk + if (bos == (size_t) -1) { + return strlcat_real(dest, src, size); + } + + // Compiler can prove, at compile time, that the passed in size + // is always <= the actual object size. Don't call __strlcat_chk + if (__builtin_constant_p(size) && (size <= bos)) { + return strlcat_real(dest, src, size); + } + + // Compiler can prove, at compile time, that the passed in size + // is always > the actual object size. Force a compiler error. + if (__builtin_constant_p(size) && (size > bos)) { + __strlcat_error(); + } + + return __strlcat_chk(dest, src, size, bos); +} + + #endif /* defined(__BIONIC_FORTIFY_INLINE) */ __END_DECLS diff --git a/libc/string/__strlcat_chk.c b/libc/string/__strlcat_chk.c new file mode 100644 index 0000000..b895fb8 --- /dev/null +++ b/libc/string/__strlcat_chk.c @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <string.h> +#include <stdlib.h> +#include <private/logd.h> + +/* + * __strlcat_chk. Called in place of strlcat() when we know the + * size of the buffer we're writing into. + * + * See + * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html + * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html + * for details. + * + * This strlcat check is called if _FORTIFY_SOURCE is defined and + * greater than 0. + */ +size_t __strlcat_chk(char *dest, const char *src, + size_t supplied_size, size_t dest_len_from_compiler) +{ + if (supplied_size > dest_len_from_compiler) { + __libc_android_log_print(ANDROID_LOG_FATAL, "libc", + "*** strlcat buffer overflow detected ***\n"); + abort(); + } + + return strlcat(dest, src, supplied_size); +} diff --git a/libc/string/__strlcpy_chk.c b/libc/string/__strlcpy_chk.c new file mode 100644 index 0000000..752c86c --- /dev/null +++ b/libc/string/__strlcpy_chk.c @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <string.h> +#include <stdlib.h> +#include <private/logd.h> + +/* + * __strlcpy_chk. Called in place of strlcpy() when we know the + * size of the buffer we're writing into. + * + * See + * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html + * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html + * for details. + * + * This strlcpy check is called if _FORTIFY_SOURCE is defined and + * greater than 0. + */ +size_t __strlcpy_chk(char *dest, const char *src, + size_t supplied_size, size_t dest_len_from_compiler) +{ + if (supplied_size > dest_len_from_compiler) { + __libc_android_log_print(ANDROID_LOG_FATAL, "libc", + "*** strlcpy buffer overflow detected ***\n"); + abort(); + } + + return strlcpy(dest, src, supplied_size); +} |