From 29951991f5db1001c059f8ed7afa2c359cdc7f44 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 8 Feb 2024 15:46:14 -0300 Subject: [PATCH] libio: Improve fortify with clang It improve fortify checks for sprintf, vsprintf, vsnsprintf, fprintf, dprintf, asprintf, __asprintf, obstack_printf, gets, fgets, fgets_unlocked, fread, and fread_unlocked. The runtime checks have similar support coverage as with GCC. For function with variadic argument (sprintf, snprintf, fprintf, printf, dprintf, asprintf, __asprintf, obstack_printf) the fortify wrapper calls the va_arg version since clang does not support __va_arg_pack. Checked on aarch64, armhf, x86_64, and i686. Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- libio/bits/stdio2.h | 173 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 153 insertions(+), 20 deletions(-) diff --git a/libio/bits/stdio2.h b/libio/bits/stdio2.h index f9e8d37610..91a80dd7c6 100644 --- a/libio/bits/stdio2.h +++ b/libio/bits/stdio2.h @@ -31,15 +31,29 @@ __NTH (sprintf (char *__restrict __s, const char *__restrict __fmt, ...)) __glibc_objsize (__s), __fmt, __va_arg_pack ()); } +#elif __fortify_use_clang +/* clang does not have __va_arg_pack, so defer to va_arg version. */ +__fortify_function_error_function __attribute_overloadable__ int +__NTH (sprintf (__fortify_clang_overload_arg (char *, __restrict, __s), + const char *__restrict __fmt, ...)) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __builtin___vsprintf_chk (__s, __USE_FORTIFY_LEVEL - 1, + __glibc_objsize (__s), __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} #elif !defined __cplusplus # define sprintf(str, ...) \ __builtin___sprintf_chk (str, __USE_FORTIFY_LEVEL - 1, \ __glibc_objsize (str), __VA_ARGS__) #endif -__fortify_function int -__NTH (vsprintf (char *__restrict __s, const char *__restrict __fmt, - __gnuc_va_list __ap)) +__fortify_function __attribute_overloadable__ int +__NTH (vsprintf (__fortify_clang_overload_arg (char *, __restrict, __s), + const char *__restrict __fmt, __gnuc_va_list __ap)) { return __builtin___vsprintf_chk (__s, __USE_FORTIFY_LEVEL - 1, __glibc_objsize (__s), __fmt, __ap); @@ -55,15 +69,33 @@ __NTH (snprintf (char *__restrict __s, size_t __n, __glibc_objsize (__s), __fmt, __va_arg_pack ()); } +# elif __fortify_use_clang +/* clang does not have __va_arg_pack, so defer to va_arg version. */ +__fortify_function_error_function __attribute_overloadable__ int +__NTH (snprintf (__fortify_clang_overload_arg (char *, __restrict, __s), + size_t __n, const char *__restrict __fmt, ...)) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __builtin___vsnprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, + __glibc_objsize (__s), __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} # elif !defined __cplusplus # define snprintf(str, len, ...) \ __builtin___snprintf_chk (str, len, __USE_FORTIFY_LEVEL - 1, \ __glibc_objsize (str), __VA_ARGS__) # endif -__fortify_function int -__NTH (vsnprintf (char *__restrict __s, size_t __n, - const char *__restrict __fmt, __gnuc_va_list __ap)) +__fortify_function __attribute_overloadable__ int +__NTH (vsnprintf (__fortify_clang_overload_arg (char *, __restrict, __s), + size_t __n, const char *__restrict __fmt, + __gnuc_va_list __ap)) + __fortify_clang_warning (__fortify_clang_bos_static_lt (__n, __s), + "call to vsnprintf may overflow the destination " + "buffer") { return __builtin___vsnprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, __glibc_objsize (__s), __fmt, __ap); @@ -85,6 +117,30 @@ printf (const char *__restrict __fmt, ...) { return __printf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, __va_arg_pack ()); } +# elif __fortify_use_clang +/* clang does not have __va_arg_pack, so defer to va_arg version. */ +__fortify_function_error_function __attribute_overloadable__ __nonnull ((1)) int +fprintf (__fortify_clang_overload_arg (FILE *, __restrict, __stream), + const char *__restrict __fmt, ...) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __builtin___vfprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, + __fmt, __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} + +__fortify_function_error_function __attribute_overloadable__ int +printf (__fortify_clang_overload_arg (const char *, __restrict, __fmt), ...) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __builtin___vprintf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} # elif !defined __cplusplus # define printf(...) \ __printf_chk (__USE_FORTIFY_LEVEL - 1, __VA_ARGS__) @@ -92,8 +148,9 @@ printf (const char *__restrict __fmt, ...) __fprintf_chk (stream, __USE_FORTIFY_LEVEL - 1, __VA_ARGS__) # endif -__fortify_function int -vprintf (const char *__restrict __fmt, __gnuc_va_list __ap) +__fortify_function __attribute_overloadable__ int +vprintf (__fortify_clang_overload_arg (const char *, __restrict, __fmt), + __gnuc_va_list __ap) { #ifdef __USE_EXTERN_INLINES return __vfprintf_chk (stdout, __USE_FORTIFY_LEVEL - 1, __fmt, __ap); @@ -117,6 +174,18 @@ dprintf (int __fd, const char *__restrict __fmt, ...) return __dprintf_chk (__fd, __USE_FORTIFY_LEVEL - 1, __fmt, __va_arg_pack ()); } +# elif __fortify_use_clang +__fortify_function_error_function __attribute_overloadable__ int +dprintf (int __fd, __fortify_clang_overload_arg (const char *, __restrict, + __fmt), ...) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __vdprintf_chk (__fd, __USE_FORTIFY_LEVEL - 1, __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} # elif !defined __cplusplus # define dprintf(fd, ...) \ __dprintf_chk (fd, __USE_FORTIFY_LEVEL - 1, __VA_ARGS__) @@ -153,6 +222,43 @@ __NTH (obstack_printf (struct obstack *__restrict __obstack, return __obstack_printf_chk (__obstack, __USE_FORTIFY_LEVEL - 1, __fmt, __va_arg_pack ()); } +# elif __fortify_use_clang +__fortify_function_error_function __attribute_overloadable__ int +__NTH (asprintf (__fortify_clang_overload_arg (char **, __restrict, __ptr), + const char *__restrict __fmt, ...)) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __vasprintf_chk (__ptr, __USE_FORTIFY_LEVEL - 1, __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} + +__fortify_function_error_function __attribute_overloadable__ int +__NTH (__asprintf (__fortify_clang_overload_arg (char **, __restrict, __ptr), + const char *__restrict __fmt, ...)) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __vasprintf_chk (__ptr, __USE_FORTIFY_LEVEL - 1, __fmt, + __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} + +__fortify_function_error_function __attribute_overloadable__ int +__NTH (obstack_printf (__fortify_clang_overload_arg (struct obstack *, + __restrict, __obstack), + const char *__restrict __fmt, ...)) +{ + __gnuc_va_list __fortify_ap; + __builtin_va_start (__fortify_ap, __fmt); + int __r = __obstack_vprintf_chk (__obstack, __USE_FORTIFY_LEVEL - 1, + __fmt, __fortify_ap); + __builtin_va_end (__fortify_ap); + return __r; +} # elif !defined __cplusplus # define asprintf(ptr, ...) \ __asprintf_chk (ptr, __USE_FORTIFY_LEVEL - 1, __VA_ARGS__) @@ -182,8 +288,11 @@ __NTH (obstack_vprintf (struct obstack *__restrict __obstack, #endif #if __GLIBC_USE (DEPRECATED_GETS) -__fortify_function __wur char * -gets (char *__str) +__fortify_function __wur __attribute_overloadable__ char * +gets (__fortify_clang_overload_arg (char *, , __str)) + __fortify_clang_warning (__glibc_objsize (__str) == (size_t) -1, + "please use fgets or getline instead, gets " + "can not specify buffer size") { if (__glibc_objsize (__str) != (size_t) -1) return __gets_chk (__str, __glibc_objsize (__str)); @@ -192,48 +301,70 @@ gets (char *__str) #endif __fortify_function __wur __fortified_attr_access (__write_only__, 1, 2) -__nonnull ((3)) char * -fgets (char *__restrict __s, int __n, FILE *__restrict __stream) +__nonnull ((3)) __attribute_overloadable__ char * +fgets (__fortify_clang_overload_arg (char *, __restrict, __s), int __n, + FILE *__restrict __stream) + __fortify_clang_warning (__fortify_clang_bos_static_lt (__n, __s) && __n > 0, + "fgets called with bigger size than length of " + "destination buffer") { size_t sz = __glibc_objsize (__s); if (__glibc_safe_or_unknown_len (__n, sizeof (char), sz)) return __fgets_alias (__s, __n, __stream); +#if !__fortify_use_clang if (__glibc_unsafe_len (__n, sizeof (char), sz)) return __fgets_chk_warn (__s, sz, __n, __stream); +#endif return __fgets_chk (__s, sz, __n, __stream); } -__fortify_function __wur __nonnull ((4)) size_t -fread (void *__restrict __ptr, size_t __size, size_t __n, - FILE *__restrict __stream) +__fortify_function __wur __nonnull ((4)) __attribute_overloadable__ size_t +fread (__fortify_clang_overload_arg (void *, __restrict, __ptr), + size_t __size, size_t __n, FILE *__restrict __stream) + __fortify_clang_warning (__fortify_clang_bos0_static_lt (__size * __n, __ptr) + && !__fortify_clang_mul_may_overflow (__size, __n), + "fread called with bigger size * n than length " + "of destination buffer") { size_t sz = __glibc_objsize0 (__ptr); if (__glibc_safe_or_unknown_len (__n, __size, sz)) return __fread_alias (__ptr, __size, __n, __stream); +#if !__fortify_use_clang if (__glibc_unsafe_len (__n, __size, sz)) return __fread_chk_warn (__ptr, sz, __size, __n, __stream); +#endif return __fread_chk (__ptr, sz, __size, __n, __stream); } #ifdef __USE_GNU __fortify_function __wur __fortified_attr_access (__write_only__, 1, 2) -__nonnull ((3)) char * -fgets_unlocked (char *__restrict __s, int __n, FILE *__restrict __stream) +__nonnull ((3)) __attribute_overloadable__ char * +fgets_unlocked (__fortify_clang_overload_arg (char *, __restrict, __s), + int __n, FILE *__restrict __stream) + __fortify_clang_warning (__fortify_clang_bos_static_lt (__n, __s) && __n > 0, + "fgets called with bigger size than length of " + "destination buffer") { size_t sz = __glibc_objsize (__s); if (__glibc_safe_or_unknown_len (__n, sizeof (char), sz)) return __fgets_unlocked_alias (__s, __n, __stream); +#if !__fortify_use_clang if (__glibc_unsafe_len (__n, sizeof (char), sz)) return __fgets_unlocked_chk_warn (__s, sz, __n, __stream); +#endif return __fgets_unlocked_chk (__s, sz, __n, __stream); } #endif #ifdef __USE_MISC # undef fread_unlocked -__fortify_function __wur __nonnull ((4)) size_t -fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n, - FILE *__restrict __stream) +__fortify_function __wur __nonnull ((4)) __attribute_overloadable__ size_t +fread_unlocked (__fortify_clang_overload_arg0 (void *, __restrict, __ptr), + size_t __size, size_t __n, FILE *__restrict __stream) + __fortify_clang_warning (__fortify_clang_bos0_static_lt (__size * __n, __ptr) + && !__fortify_clang_mul_may_overflow (__size, __n), + "fread_unlocked called with bigger size * n than " + "length of destination buffer") { size_t sz = __glibc_objsize0 (__ptr); if (__glibc_safe_or_unknown_len (__n, __size, sz)) @@ -261,8 +392,10 @@ fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n, # endif return __fread_unlocked_alias (__ptr, __size, __n, __stream); } +# if !__fortify_use_clang if (__glibc_unsafe_len (__n, __size, sz)) return __fread_unlocked_chk_warn (__ptr, sz, __size, __n, __stream); +# endif return __fread_unlocked_chk (__ptr, sz, __size, __n, __stream); } -- 2.11.4.GIT