diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-26 22:19:04 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-26 22:19:04 +0300 |
commit | 4be240b18aa67b1144af546bea2d7cad1b75c19b (patch) | |
tree | f95b3ca5c3f5de5b634da578b55f85d2ae89c5de | |
parent | 3f7282139fe1594be464b90141d56738e7a0ea8a (diff) | |
parent | 281d0c962752fb40866dd8d4cade68656f34bd1f (diff) | |
download | linux-4be240b18aa67b1144af546bea2d7cad1b75c19b.tar.xz |
Merge tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull FORTIFY_SOURCE updates from Kees Cook:
"This series consists of two halves:
- strict compile-time buffer size checking under FORTIFY_SOURCE for
the memcpy()-family of functions (for extensive details and
rationale, see the first commit)
- enabling FORTIFY_SOURCE for Clang, which has had many overlapping
bugs that we've finally worked past"
* tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
fortify: Add Clang support
fortify: Make sure strlen() may still be used as a constant expression
fortify: Use __diagnose_as() for better diagnostic coverage
fortify: Make pointer arguments const
Compiler Attributes: Add __diagnose_as for Clang
Compiler Attributes: Add __overloadable for Clang
Compiler Attributes: Add __pass_object_size for Clang
fortify: Replace open-coded __gnu_inline attribute
fortify: Update compile-time tests for Clang 14
fortify: Detect struct member overflows in memset() at compile-time
fortify: Detect struct member overflows in memmove() at compile-time
fortify: Detect struct member overflows in memcpy() at compile-time
-rw-r--r-- | arch/x86/boot/compressed/misc.c | 3 | ||||
-rw-r--r-- | arch/x86/lib/memcpy_32.c | 1 | ||||
-rw-r--r-- | include/linux/compiler_attributes.h | 39 | ||||
-rw-r--r-- | include/linux/fortify-string.h | 238 | ||||
-rw-r--r-- | lib/Makefile | 3 | ||||
-rw-r--r-- | lib/string_helpers.c | 6 | ||||
-rw-r--r-- | lib/test_fortify/read_overflow2_field-memcpy.c | 5 | ||||
-rw-r--r-- | lib/test_fortify/read_overflow2_field-memmove.c | 5 | ||||
-rw-r--r-- | lib/test_fortify/write_overflow_field-memcpy.c | 5 | ||||
-rw-r--r-- | lib/test_fortify/write_overflow_field-memmove.c | 5 | ||||
-rw-r--r-- | lib/test_fortify/write_overflow_field-memset.c | 5 | ||||
-rw-r--r-- | scripts/test_fortify.sh | 8 | ||||
-rw-r--r-- | security/Kconfig | 5 |
13 files changed, 272 insertions, 56 deletions
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index a4339cb2d247..1cdcaf34ee36 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -37,10 +37,11 @@ * try to define their own functions if these are not defined as macros. */ #define memzero(s, n) memset((s), 0, (n)) +#ifndef memmove #define memmove memmove - /* Functions used by the included decompressor code below. */ void *memmove(void *dest, const void *src, size_t n); +#endif /* * This is set up by the setup-routine at boot-time diff --git a/arch/x86/lib/memcpy_32.c b/arch/x86/lib/memcpy_32.c index 3a6e6cfe8c35..ef3af7ff2c8a 100644 --- a/arch/x86/lib/memcpy_32.c +++ b/arch/x86/lib/memcpy_32.c @@ -4,6 +4,7 @@ #undef memcpy #undef memset +#undef memmove __visible void *memcpy(void *to, const void *from, size_t n) { diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 37e260020221..445e80517cab 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -101,6 +101,19 @@ #endif /* + * Optional: not supported by gcc + * Optional: only supported since clang >= 14.0 + * Optional: not supported by icc + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#diagnose_as_builtin + */ +#if __has_attribute(__diagnose_as_builtin__) +# define __diagnose_as(builtin...) __attribute__((__diagnose_as_builtin__(builtin))) +#else +# define __diagnose_as(builtin...) +#endif + +/* * Don't. Just don't. See commit 771c035372a0 ("deprecate the '__deprecated' * attribute warnings entirely and for good") for more information. * @@ -258,12 +271,38 @@ #define __noreturn __attribute__((__noreturn__)) /* + * Optional: not supported by gcc. + * Optional: not supported by icc. + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#overloadable + */ +#if __has_attribute(__overloadable__) +# define __overloadable __attribute__((__overloadable__)) +#else +# define __overloadable +#endif + +/* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-packed-type-attribute * clang: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-packed-variable-attribute */ #define __packed __attribute__((__packed__)) /* + * Note: the "type" argument should match any __builtin_object_size(p, type) usage. + * + * Optional: not supported by gcc. + * Optional: not supported by icc. + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#pass-object-size-pass-dynamic-object-size + */ +#if __has_attribute(__pass_object_size__) +# define __pass_object_size(type) __attribute__((__pass_object_size__(type))) +#else +# define __pass_object_size(type) +#endif + +/* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute */ #define __pure __attribute__((__pure__)) diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index a6cd6815f249..295637a66c46 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -2,13 +2,17 @@ #ifndef _LINUX_FORTIFY_STRING_H_ #define _LINUX_FORTIFY_STRING_H_ -#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) +#include <linux/const.h> + +#define __FORTIFY_INLINE extern __always_inline __gnu_inline __overloadable #define __RENAME(x) __asm__(#x) void fortify_panic(const char *name) __noreturn __cold; void __read_overflow(void) __compiletime_error("detected read beyond size of object (1st parameter)"); void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)"); +void __read_overflow2_field(size_t avail, size_t wanted) __compiletime_warning("detected read beyond size of field (2nd parameter); maybe use struct_group()?"); void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)"); +void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning("detected write beyond size of field (1st parameter); maybe use struct_group()?"); #define __compiletime_strlen(p) \ ({ \ @@ -48,7 +52,17 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) #define __underlying_strncpy __builtin_strncpy #endif -__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) +/* + * Clang's use of __builtin_object_size() within inlines needs hinting via + * __pass_object_size(). The preference is to only ever use type 1 (member + * size, rather than struct size), but there remain some stragglers using + * type 0 that will be converted in the future. + */ +#define POS __pass_object_size(1) +#define POS0 __pass_object_size(0) + +__FORTIFY_INLINE __diagnose_as(__builtin_strncpy, 1, 2, 3) +char *strncpy(char * const POS p, const char *q, __kernel_size_t size) { size_t p_size = __builtin_object_size(p, 1); @@ -59,7 +73,8 @@ __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) return __underlying_strncpy(p, q, size); } -__FORTIFY_INLINE char *strcat(char *p, const char *q) +__FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2) +char *strcat(char * const POS p, const char *q) { size_t p_size = __builtin_object_size(p, 1); @@ -71,7 +86,7 @@ __FORTIFY_INLINE char *strcat(char *p, const char *q) } extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen); -__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen) +__FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size_t maxlen) { size_t p_size = __builtin_object_size(p, 1); size_t p_len = __compiletime_strlen(p); @@ -91,8 +106,16 @@ __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen) return ret; } -/* defined after fortified strnlen to reuse it. */ -__FORTIFY_INLINE __kernel_size_t strlen(const char *p) +/* + * Defined after fortified strnlen to reuse it. However, it must still be + * possible for strlen() to be used on compile-time strings for use in + * static initializers (i.e. as a constant expression). + */ +#define strlen(p) \ + __builtin_choose_expr(__is_constexpr(__builtin_strlen(p)), \ + __builtin_strlen(p), __fortify_strlen(p)) +__FORTIFY_INLINE __diagnose_as(__builtin_strlen, 1) +__kernel_size_t __fortify_strlen(const char * const POS p) { __kernel_size_t ret; size_t p_size = __builtin_object_size(p, 1); @@ -108,7 +131,7 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p) /* defined after fortified strlen to reuse it */ extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); -__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size) +__FORTIFY_INLINE size_t strlcpy(char * const POS p, const char * const POS q, size_t size) { size_t p_size = __builtin_object_size(p, 1); size_t q_size = __builtin_object_size(q, 1); @@ -135,7 +158,7 @@ __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size) /* defined after fortified strnlen to reuse it */ extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy); -__FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size) +__FORTIFY_INLINE ssize_t strscpy(char * const POS p, const char * const POS q, size_t size) { size_t len; /* Use string size rather than possible enclosing struct size. */ @@ -181,7 +204,8 @@ __FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size) } /* defined after fortified strlen and strnlen to reuse them */ -__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) +__FORTIFY_INLINE __diagnose_as(__builtin_strncat, 1, 2, 3) +char *strncat(char * const POS p, const char * const POS q, __kernel_size_t count) { size_t p_len, copy_len; size_t p_size = __builtin_object_size(p, 1); @@ -198,51 +222,161 @@ __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) return p; } -__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size) +__FORTIFY_INLINE void fortify_memset_chk(__kernel_size_t size, + const size_t p_size, + const size_t p_size_field) { - size_t p_size = __builtin_object_size(p, 0); - - if (__builtin_constant_p(size) && p_size < size) - __write_overflow(); - if (p_size < size) - fortify_panic(__func__); - return __underlying_memset(p, c, size); -} - -__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size) -{ - size_t p_size = __builtin_object_size(p, 0); - size_t q_size = __builtin_object_size(q, 0); - if (__builtin_constant_p(size)) { - if (p_size < size) + /* + * Length argument is a constant expression, so we + * can perform compile-time bounds checking where + * buffer sizes are known. + */ + + /* Error when size is larger than enclosing struct. */ + if (p_size > p_size_field && p_size < size) __write_overflow(); - if (q_size < size) - __read_overflow2(); + + /* Warn when write size is larger than dest field. */ + if (p_size_field < size) + __write_overflow_field(p_size_field, size); } - if (p_size < size || q_size < size) - fortify_panic(__func__); - return __underlying_memcpy(p, q, size); + /* + * At this point, length argument may not be a constant expression, + * so run-time bounds checking can be done where buffer sizes are + * known. (This is not an "else" because the above checks may only + * be compile-time warnings, and we want to still warn for run-time + * overflows.) + */ + + /* + * Always stop accesses beyond the struct that contains the + * field, when the buffer's remaining size is known. + * (The -1 test is to optimize away checks where the buffer + * lengths are unknown.) + */ + if (p_size != (size_t)(-1) && p_size < size) + fortify_panic("memset"); } -__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size) -{ - size_t p_size = __builtin_object_size(p, 0); - size_t q_size = __builtin_object_size(q, 0); +#define __fortify_memset_chk(p, c, size, p_size, p_size_field) ({ \ + size_t __fortify_size = (size_t)(size); \ + fortify_memset_chk(__fortify_size, p_size, p_size_field), \ + __underlying_memset(p, c, __fortify_size); \ +}) +/* + * __builtin_object_size() must be captured here to avoid evaluating argument + * side-effects further into the macro layers. + */ +#define memset(p, c, s) __fortify_memset_chk(p, c, s, \ + __builtin_object_size(p, 0), __builtin_object_size(p, 1)) + +/* + * To make sure the compiler can enforce protection against buffer overflows, + * memcpy(), memmove(), and memset() must not be used beyond individual + * struct members. If you need to copy across multiple members, please use + * struct_group() to create a named mirror of an anonymous struct union. + * (e.g. see struct sk_buff.) Read overflow checking is currently only + * done when a write overflow is also present, or when building with W=1. + * + * Mitigation coverage matrix + * Bounds checking at: + * +-------+-------+-------+-------+ + * | Compile time | Run time | + * memcpy() argument sizes: | write | read | write | read | + * dest source length +-------+-------+-------+-------+ + * memcpy(known, known, constant) | y | y | n/a | n/a | + * memcpy(known, unknown, constant) | y | n | n/a | V | + * memcpy(known, known, dynamic) | n | n | B | B | + * memcpy(known, unknown, dynamic) | n | n | B | V | + * memcpy(unknown, known, constant) | n | y | V | n/a | + * memcpy(unknown, unknown, constant) | n | n | V | V | + * memcpy(unknown, known, dynamic) | n | n | V | B | + * memcpy(unknown, unknown, dynamic) | n | n | V | V | + * +-------+-------+-------+-------+ + * + * y = perform deterministic compile-time bounds checking + * n = cannot perform deterministic compile-time bounds checking + * n/a = no run-time bounds checking needed since compile-time deterministic + * B = can perform run-time bounds checking (currently unimplemented) + * V = vulnerable to run-time overflow (will need refactoring to solve) + * + */ +__FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size, + const size_t p_size, + const size_t q_size, + const size_t p_size_field, + const size_t q_size_field, + const char *func) +{ if (__builtin_constant_p(size)) { - if (p_size < size) + /* + * Length argument is a constant expression, so we + * can perform compile-time bounds checking where + * buffer sizes are known. + */ + + /* Error when size is larger than enclosing struct. */ + if (p_size > p_size_field && p_size < size) __write_overflow(); - if (q_size < size) + if (q_size > q_size_field && q_size < size) __read_overflow2(); + + /* Warn when write size argument larger than dest field. */ + if (p_size_field < size) + __write_overflow_field(p_size_field, size); + /* + * Warn for source field over-read when building with W=1 + * or when an over-write happened, so both can be fixed at + * the same time. + */ + if ((IS_ENABLED(KBUILD_EXTRA_WARN1) || p_size_field < size) && + q_size_field < size) + __read_overflow2_field(q_size_field, size); } - if (p_size < size || q_size < size) - fortify_panic(__func__); - return __underlying_memmove(p, q, size); + /* + * At this point, length argument may not be a constant expression, + * so run-time bounds checking can be done where buffer sizes are + * known. (This is not an "else" because the above checks may only + * be compile-time warnings, and we want to still warn for run-time + * overflows.) + */ + + /* + * Always stop accesses beyond the struct that contains the + * field, when the buffer's remaining size is known. + * (The -1 test is to optimize away checks where the buffer + * lengths are unknown.) + */ + if ((p_size != (size_t)(-1) && p_size < size) || + (q_size != (size_t)(-1) && q_size < size)) + fortify_panic(func); } +#define __fortify_memcpy_chk(p, q, size, p_size, q_size, \ + p_size_field, q_size_field, op) ({ \ + size_t __fortify_size = (size_t)(size); \ + fortify_memcpy_chk(__fortify_size, p_size, q_size, \ + p_size_field, q_size_field, #op); \ + __underlying_##op(p, q, __fortify_size); \ +}) + +/* + * __builtin_object_size() must be captured here to avoid evaluating argument + * side-effects further into the macro layers. + */ +#define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ + __builtin_object_size(p, 0), __builtin_object_size(q, 0), \ + __builtin_object_size(p, 1), __builtin_object_size(q, 1), \ + memcpy) +#define memmove(p, q, s) __fortify_memcpy_chk(p, q, s, \ + __builtin_object_size(p, 0), __builtin_object_size(q, 0), \ + __builtin_object_size(p, 1), __builtin_object_size(q, 1), \ + memmove) + extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); -__FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) +__FORTIFY_INLINE void *memscan(void * const POS0 p, int c, __kernel_size_t size) { size_t p_size = __builtin_object_size(p, 0); @@ -253,7 +387,8 @@ __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) return __real_memscan(p, c, size); } -__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) +__FORTIFY_INLINE __diagnose_as(__builtin_memcmp, 1, 2, 3) +int memcmp(const void * const POS0 p, const void * const POS0 q, __kernel_size_t size) { size_t p_size = __builtin_object_size(p, 0); size_t q_size = __builtin_object_size(q, 0); @@ -269,7 +404,8 @@ __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) return __underlying_memcmp(p, q, size); } -__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) +__FORTIFY_INLINE __diagnose_as(__builtin_memchr, 1, 2, 3) +void *memchr(const void * const POS0 p, int c, __kernel_size_t size) { size_t p_size = __builtin_object_size(p, 0); @@ -281,7 +417,7 @@ __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) } void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv); -__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size) +__FORTIFY_INLINE void *memchr_inv(const void * const POS0 p, int c, size_t size) { size_t p_size = __builtin_object_size(p, 0); @@ -293,7 +429,7 @@ __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size) } extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup); -__FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp) +__FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp) { size_t p_size = __builtin_object_size(p, 0); @@ -304,13 +440,15 @@ __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp) return __real_kmemdup(p, size, gfp); } -/* defined after fortified strlen and memcpy to reuse them */ -__FORTIFY_INLINE char *strcpy(char *p, const char *q) +/* Defined after fortified strlen to reuse it. */ +__FORTIFY_INLINE __diagnose_as(__builtin_strcpy, 1, 2) +char *strcpy(char * const POS p, const char * const POS q) { size_t p_size = __builtin_object_size(p, 1); size_t q_size = __builtin_object_size(q, 1); size_t size; + /* If neither buffer size is known, immediately give up. */ if (p_size == (size_t)-1 && q_size == (size_t)-1) return __underlying_strcpy(p, q); size = strlen(q) + 1; @@ -320,20 +458,20 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q) /* Run-time check for dynamic size overflow. */ if (p_size < size) fortify_panic(__func__); - memcpy(p, q, size); + __underlying_memcpy(p, q, size); return p; } /* Don't use these outside the FORITFY_SOURCE implementation */ #undef __underlying_memchr #undef __underlying_memcmp -#undef __underlying_memcpy -#undef __underlying_memmove -#undef __underlying_memset #undef __underlying_strcat #undef __underlying_strcpy #undef __underlying_strlen #undef __underlying_strncat #undef __underlying_strncpy +#undef POS +#undef POS0 + #endif /* _LINUX_FORTIFY_STRING_H_ */ diff --git a/lib/Makefile b/lib/Makefile index df001b876930..6b9ffc1bd1ee 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -377,7 +377,8 @@ TEST_FORTIFY_LOG = test_fortify.log quiet_cmd_test_fortify = TEST $@ cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \ $< $@ "$(NM)" $(CC) $(c_flags) \ - $(call cc-disable-warning,fortify-source) + $(call cc-disable-warning,fortify-source) \ + -DKBUILD_EXTRA_WARN1 targets += $(TEST_FORTIFY_LOGS) clean-files += $(TEST_FORTIFY_LOGS) diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 90f9f1b7afec..4f877e9551d5 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -968,6 +968,12 @@ void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, EXPORT_SYMBOL(memcpy_and_pad); #ifdef CONFIG_FORTIFY_SOURCE +/* These are placeholders for fortify compile-time warnings. */ +void __read_overflow2_field(size_t avail, size_t wanted) { } +EXPORT_SYMBOL(__read_overflow2_field); +void __write_overflow_field(size_t avail, size_t wanted) { } +EXPORT_SYMBOL(__write_overflow_field); + void fortify_panic(const char *name) { pr_emerg("detected buffer overflow in %s\n", name); diff --git a/lib/test_fortify/read_overflow2_field-memcpy.c b/lib/test_fortify/read_overflow2_field-memcpy.c new file mode 100644 index 000000000000..de9569266223 --- /dev/null +++ b/lib/test_fortify/read_overflow2_field-memcpy.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define TEST \ + memcpy(large, instance.buf, sizeof(instance.buf) + 1) + +#include "test_fortify.h" diff --git a/lib/test_fortify/read_overflow2_field-memmove.c b/lib/test_fortify/read_overflow2_field-memmove.c new file mode 100644 index 000000000000..6cc2724c8f62 --- /dev/null +++ b/lib/test_fortify/read_overflow2_field-memmove.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define TEST \ + memmove(large, instance.buf, sizeof(instance.buf) + 1) + +#include "test_fortify.h" diff --git a/lib/test_fortify/write_overflow_field-memcpy.c b/lib/test_fortify/write_overflow_field-memcpy.c new file mode 100644 index 000000000000..28cc81058dd3 --- /dev/null +++ b/lib/test_fortify/write_overflow_field-memcpy.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define TEST \ + memcpy(instance.buf, large, sizeof(instance.buf) + 1) + +#include "test_fortify.h" diff --git a/lib/test_fortify/write_overflow_field-memmove.c b/lib/test_fortify/write_overflow_field-memmove.c new file mode 100644 index 000000000000..377fcf9bb2fd --- /dev/null +++ b/lib/test_fortify/write_overflow_field-memmove.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define TEST \ + memmove(instance.buf, large, sizeof(instance.buf) + 1) + +#include "test_fortify.h" diff --git a/lib/test_fortify/write_overflow_field-memset.c b/lib/test_fortify/write_overflow_field-memset.c new file mode 100644 index 000000000000..2331da26909e --- /dev/null +++ b/lib/test_fortify/write_overflow_field-memset.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define TEST \ + memset(instance.buf, 0x42, sizeof(instance.buf) + 1) + +#include "test_fortify.h" diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh index a4da365508f0..c2688ab8281d 100644 --- a/scripts/test_fortify.sh +++ b/scripts/test_fortify.sh @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" fi else - # If the build failed, check for the warning in the stderr (gcc). - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then + # If the build failed, check for the warning in the stderr. + # GCC: + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] + # Clang 14: + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then status="warning: unsafe ${FUNC}() usage lacked '$WANT' warning in $IN" fi fi diff --git a/security/Kconfig b/security/Kconfig index 0b847f435beb..1d2d71cc1f36 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -177,9 +177,10 @@ config HARDENED_USERCOPY_PAGESPAN config FORTIFY_SOURCE bool "Harden common str/mem functions against buffer overflows" depends on ARCH_HAS_FORTIFY_SOURCE - # https://bugs.llvm.org/show_bug.cgi?id=50322 # https://bugs.llvm.org/show_bug.cgi?id=41459 - depends on !CC_IS_CLANG + depends on !CC_IS_CLANG || CLANG_VERSION >= 120001 + # https://github.com/llvm/llvm-project/issues/53645 + depends on !CC_IS_CLANG || !X86_32 help Detect overflows of buffers in common string and memory functions where the compiler can determine and validate the buffer sizes. |