From: Kees Cook <keescook@xxxxxxxxxxxx> Subject: fortify: use WARN instead of BUG for now While CONFIG_FORTIFY_SOURCE continues to shake out, don't unconditionally use BUG(), opting instead for WARN(). This also renames fortify_panic() to fortify_overflow() which better matches what it is being called for. [akpm@xxxxxxxxxxxxxxxxxxxx: remove fortify_overflow from tools/objtool/check.c:global_noreturns, per Josh] Link: http://lkml.kernel.org/r/20170726185219.GA57833@beast Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Daniel Micay <danielmicay@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/boot/compressed/misc.c | 2 +- include/linux/string.h | 30 +++++++++++++++--------------- lib/string.c | 7 +++---- tools/objtool/check.c | 1 - 4 files changed, 19 insertions(+), 21 deletions(-) diff -puN arch/x86/boot/compressed/misc.c~fortify-use-warn-instead-of-bug-for-now arch/x86/boot/compressed/misc.c --- a/arch/x86/boot/compressed/misc.c~fortify-use-warn-instead-of-bug-for-now +++ a/arch/x86/boot/compressed/misc.c @@ -412,7 +412,7 @@ asmlinkage __visible void *extract_kerne return output; } -void fortify_panic(const char *name) +void fortify_overflow(const char *name) { error("detected buffer overflow"); } diff -puN include/linux/string.h~fortify-use-warn-instead-of-bug-for-now include/linux/string.h --- a/include/linux/string.h~fortify-use-warn-instead-of-bug-for-now +++ a/include/linux/string.h @@ -197,7 +197,7 @@ static inline const char *kbasename(cons #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) #define __RENAME(x) __asm__(#x) -void fortify_panic(const char *name) __noreturn __cold; +void fortify_overflow(const char *name) __cold; void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); @@ -209,7 +209,7 @@ __FORTIFY_INLINE char *strncpy(char *p, if (__builtin_constant_p(size) && p_size < size) __write_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_strncpy(p, q, size); } @@ -219,7 +219,7 @@ __FORTIFY_INLINE char *strcat(char *p, c if (p_size == (size_t)-1) return __builtin_strcat(p, q); if (strlcat(p, q, p_size) >= p_size) - fortify_panic(__func__); + fortify_overflow(__func__); return p; } @@ -231,7 +231,7 @@ __FORTIFY_INLINE __kernel_size_t strlen( return __builtin_strlen(p); ret = strnlen(p, p_size); if (p_size <= ret) - fortify_panic(__func__); + fortify_overflow(__func__); return ret; } @@ -241,7 +241,7 @@ __FORTIFY_INLINE __kernel_size_t strnlen size_t p_size = __builtin_object_size(p, 0); __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size); if (p_size <= ret && maxlen != ret) - fortify_panic(__func__); + fortify_overflow(__func__); return ret; } @@ -260,7 +260,7 @@ __FORTIFY_INLINE size_t strlcpy(char *p, if (__builtin_constant_p(len) && len >= p_size) __write_overflow(); if (len >= p_size) - fortify_panic(__func__); + fortify_overflow(__func__); __builtin_memcpy(p, q, len); p[len] = '\0'; } @@ -278,7 +278,7 @@ __FORTIFY_INLINE char *strncat(char *p, p_len = strlen(p); copy_len = strnlen(q, count); if (p_size < p_len + copy_len + 1) - fortify_panic(__func__); + fortify_overflow(__func__); __builtin_memcpy(p + p_len, q, copy_len); p[p_len + copy_len] = '\0'; return p; @@ -290,7 +290,7 @@ __FORTIFY_INLINE void *memset(void *p, i if (__builtin_constant_p(size) && p_size < size) __write_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_memset(p, c, size); } @@ -305,7 +305,7 @@ __FORTIFY_INLINE void *memcpy(void *p, c __read_overflow2(); } if (p_size < size || q_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_memcpy(p, q, size); } @@ -320,7 +320,7 @@ __FORTIFY_INLINE void *memmove(void *p, __read_overflow2(); } if (p_size < size || q_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_memmove(p, q, size); } @@ -331,7 +331,7 @@ __FORTIFY_INLINE void *memscan(void *p, if (__builtin_constant_p(size) && p_size < size) __read_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __real_memscan(p, c, size); } @@ -346,7 +346,7 @@ __FORTIFY_INLINE int memcmp(const void * __read_overflow2(); } if (p_size < size || q_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_memcmp(p, q, size); } @@ -356,7 +356,7 @@ __FORTIFY_INLINE void *memchr(const void if (__builtin_constant_p(size) && p_size < size) __read_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __builtin_memchr(p, c, size); } @@ -367,7 +367,7 @@ __FORTIFY_INLINE void *memchr_inv(const if (__builtin_constant_p(size) && p_size < size) __read_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __real_memchr_inv(p, c, size); } @@ -378,7 +378,7 @@ __FORTIFY_INLINE void *kmemdup(const voi if (__builtin_constant_p(size) && p_size < size) __read_overflow(); if (p_size < size) - fortify_panic(__func__); + fortify_overflow(__func__); return __real_kmemdup(p, size, gfp); } diff -puN lib/string.c~fortify-use-warn-instead-of-bug-for-now lib/string.c --- a/lib/string.c~fortify-use-warn-instead-of-bug-for-now +++ a/lib/string.c @@ -979,9 +979,8 @@ char *strreplace(char *s, char old, char } EXPORT_SYMBOL(strreplace); -void fortify_panic(const char *name) +void fortify_overflow(const char *name) { - pr_emerg("detected buffer overflow in %s\n", name); - BUG(); + WARN(1, "detected buffer overflow in %s\n", name); } -EXPORT_SYMBOL(fortify_panic); +EXPORT_SYMBOL(fortify_overflow); diff -puN tools/objtool/check.c~fortify-use-warn-instead-of-bug-for-now tools/objtool/check.c --- a/tools/objtool/check.c~fortify-use-warn-instead-of-bug-for-now +++ a/tools/objtool/check.c @@ -156,7 +156,6 @@ static int __dead_end_function(struct ob "kvm_spurious_fault", "__reiserfs_panic", "lbug_with_loc", - "fortify_panic", }; if (func->bind == STB_WEAK) _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
