Message ID | 20230407192717.636137-4-keescook@chromium.org (mailing list archive) |
---|---|
State | Changes Requested |
Headers | show |
Series | fortify: Add KUnit tests for runtime overflows | expand |
On Fri, Apr 7, 2023 at 12:27 PM Kees Cook <keescook@chromium.org> wrote: > > The sizes reported by __member_size should never change in a given > function. Mark them as such. > > Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Thanks for the patch! Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > --- > include/linux/fortify-string.h | 42 +++++++++++++++++----------------- > 1 file changed, 21 insertions(+), 21 deletions(-) > > diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h > index c9de1f59ee80..fae1bf4bd543 100644 > --- a/include/linux/fortify-string.h > +++ b/include/linux/fortify-string.h > @@ -20,7 +20,7 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning(" > ({ \ > char *__p = (char *)(p); \ > size_t __ret = SIZE_MAX; \ > - size_t __p_size = __member_size(p); \ > + const size_t __p_size = __member_size(p); \ > if (__p_size != SIZE_MAX && \ > __builtin_constant_p(*__p)) { \ > size_t __p_len = __p_size - 1; \ > @@ -142,7 +142,7 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) > __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 = __member_size(p); > + const size_t p_size = __member_size(p); > > if (__compiletime_lessthan(p_size, size)) > __write_overflow(); > @@ -169,7 +169,7 @@ char *strncpy(char * const POS p, const char *q, __kernel_size_t size) > __FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2) > char *strcat(char * const POS p, const char *q) > { > - size_t p_size = __member_size(p); > + const size_t p_size = __member_size(p); > > if (p_size == SIZE_MAX) > return __underlying_strcat(p, q); > @@ -191,8 +191,8 @@ extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(st > */ > __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size_t maxlen) > { > - size_t p_size = __member_size(p); > - size_t p_len = __compiletime_strlen(p); > + const size_t p_size = __member_size(p); > + const size_t p_len = __compiletime_strlen(p); > size_t ret; > > /* We can take compile-time actions when maxlen is const. */ > @@ -233,8 +233,8 @@ __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size > __FORTIFY_INLINE __diagnose_as(__builtin_strlen, 1) > __kernel_size_t __fortify_strlen(const char * const POS p) > { > + const size_t p_size = __member_size(p); > __kernel_size_t ret; > - size_t p_size = __member_size(p); > > /* Give up if we don't know how large p is. */ > if (p_size == SIZE_MAX) > @@ -267,8 +267,8 @@ extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); > */ > __FORTIFY_INLINE size_t strlcpy(char * const POS p, const char * const POS q, size_t size) > { > - size_t p_size = __member_size(p); > - size_t q_size = __member_size(q); > + const size_t p_size = __member_size(p); > + const size_t q_size = __member_size(q); > size_t q_len; /* Full count of source string length. */ > size_t len; /* Count of characters going into destination. */ > > @@ -318,10 +318,10 @@ extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy); > */ > __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. */ > - size_t p_size = __member_size(p); > - size_t q_size = __member_size(q); > + const size_t p_size = __member_size(p); > + const size_t q_size = __member_size(q); > + size_t len; > > /* If we cannot get size of p and q default to call strscpy. */ > if (p_size == SIZE_MAX && q_size == SIZE_MAX) > @@ -394,9 +394,9 @@ __FORTIFY_INLINE ssize_t strscpy(char * const POS p, const char * const POS q, s > __FORTIFY_INLINE __diagnose_as(__builtin_strncat, 1, 2, 3) > char *strncat(char * const POS p, const char * const POS q, __kernel_size_t count) > { > + const size_t p_size = __member_size(p); > + const size_t q_size = __member_size(q); > size_t p_len, copy_len; > - size_t p_size = __member_size(p); > - size_t q_size = __member_size(q); > > if (p_size == SIZE_MAX && q_size == SIZE_MAX) > return __underlying_strncat(p, q, count); > @@ -639,7 +639,7 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, > extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); > __FORTIFY_INLINE void *memscan(void * const POS0 p, int c, __kernel_size_t size) > { > - size_t p_size = __struct_size(p); > + const size_t p_size = __struct_size(p); > > if (__compiletime_lessthan(p_size, size)) > __read_overflow(); > @@ -651,8 +651,8 @@ __FORTIFY_INLINE void *memscan(void * const POS0 p, int c, __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 = __struct_size(p); > - size_t q_size = __struct_size(q); > + const size_t p_size = __struct_size(p); > + const size_t q_size = __struct_size(q); > > if (__builtin_constant_p(size)) { > if (__compiletime_lessthan(p_size, size)) > @@ -668,7 +668,7 @@ int memcmp(const void * const POS0 p, const void * const POS0 q, __kernel_size_t > __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 = __struct_size(p); > + const size_t p_size = __struct_size(p); > > if (__compiletime_lessthan(p_size, size)) > __read_overflow(); > @@ -680,7 +680,7 @@ void *memchr(const void * const POS0 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 * const POS0 p, int c, size_t size) > { > - size_t p_size = __struct_size(p); > + const size_t p_size = __struct_size(p); > > if (__compiletime_lessthan(p_size, size)) > __read_overflow(); > @@ -693,7 +693,7 @@ extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kme > __realloc_size(2); > __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp) > { > - size_t p_size = __struct_size(p); > + const size_t p_size = __struct_size(p); > > if (__compiletime_lessthan(p_size, size)) > __read_overflow(); > @@ -720,8 +720,8 @@ __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp > __FORTIFY_INLINE __diagnose_as(__builtin_strcpy, 1, 2) > char *strcpy(char * const POS p, const char * const POS q) > { > - size_t p_size = __member_size(p); > - size_t q_size = __member_size(q); > + const size_t p_size = __member_size(p); > + const size_t q_size = __member_size(q); > size_t size; > > /* If neither buffer size is known, immediately give up. */ > -- > 2.34.1 >
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index c9de1f59ee80..fae1bf4bd543 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -20,7 +20,7 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning(" ({ \ char *__p = (char *)(p); \ size_t __ret = SIZE_MAX; \ - size_t __p_size = __member_size(p); \ + const size_t __p_size = __member_size(p); \ if (__p_size != SIZE_MAX && \ __builtin_constant_p(*__p)) { \ size_t __p_len = __p_size - 1; \ @@ -142,7 +142,7 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __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 = __member_size(p); + const size_t p_size = __member_size(p); if (__compiletime_lessthan(p_size, size)) __write_overflow(); @@ -169,7 +169,7 @@ char *strncpy(char * const POS p, const char *q, __kernel_size_t size) __FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2) char *strcat(char * const POS p, const char *q) { - size_t p_size = __member_size(p); + const size_t p_size = __member_size(p); if (p_size == SIZE_MAX) return __underlying_strcat(p, q); @@ -191,8 +191,8 @@ extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(st */ __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size_t maxlen) { - size_t p_size = __member_size(p); - size_t p_len = __compiletime_strlen(p); + const size_t p_size = __member_size(p); + const size_t p_len = __compiletime_strlen(p); size_t ret; /* We can take compile-time actions when maxlen is const. */ @@ -233,8 +233,8 @@ __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size __FORTIFY_INLINE __diagnose_as(__builtin_strlen, 1) __kernel_size_t __fortify_strlen(const char * const POS p) { + const size_t p_size = __member_size(p); __kernel_size_t ret; - size_t p_size = __member_size(p); /* Give up if we don't know how large p is. */ if (p_size == SIZE_MAX) @@ -267,8 +267,8 @@ extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); */ __FORTIFY_INLINE size_t strlcpy(char * const POS p, const char * const POS q, size_t size) { - size_t p_size = __member_size(p); - size_t q_size = __member_size(q); + const size_t p_size = __member_size(p); + const size_t q_size = __member_size(q); size_t q_len; /* Full count of source string length. */ size_t len; /* Count of characters going into destination. */ @@ -318,10 +318,10 @@ extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy); */ __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. */ - size_t p_size = __member_size(p); - size_t q_size = __member_size(q); + const size_t p_size = __member_size(p); + const size_t q_size = __member_size(q); + size_t len; /* If we cannot get size of p and q default to call strscpy. */ if (p_size == SIZE_MAX && q_size == SIZE_MAX) @@ -394,9 +394,9 @@ __FORTIFY_INLINE ssize_t strscpy(char * const POS p, const char * const POS q, s __FORTIFY_INLINE __diagnose_as(__builtin_strncat, 1, 2, 3) char *strncat(char * const POS p, const char * const POS q, __kernel_size_t count) { + const size_t p_size = __member_size(p); + const size_t q_size = __member_size(q); size_t p_len, copy_len; - size_t p_size = __member_size(p); - size_t q_size = __member_size(q); if (p_size == SIZE_MAX && q_size == SIZE_MAX) return __underlying_strncat(p, q, count); @@ -639,7 +639,7 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); __FORTIFY_INLINE void *memscan(void * const POS0 p, int c, __kernel_size_t size) { - size_t p_size = __struct_size(p); + const size_t p_size = __struct_size(p); if (__compiletime_lessthan(p_size, size)) __read_overflow(); @@ -651,8 +651,8 @@ __FORTIFY_INLINE void *memscan(void * const POS0 p, int c, __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 = __struct_size(p); - size_t q_size = __struct_size(q); + const size_t p_size = __struct_size(p); + const size_t q_size = __struct_size(q); if (__builtin_constant_p(size)) { if (__compiletime_lessthan(p_size, size)) @@ -668,7 +668,7 @@ int memcmp(const void * const POS0 p, const void * const POS0 q, __kernel_size_t __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 = __struct_size(p); + const size_t p_size = __struct_size(p); if (__compiletime_lessthan(p_size, size)) __read_overflow(); @@ -680,7 +680,7 @@ void *memchr(const void * const POS0 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 * const POS0 p, int c, size_t size) { - size_t p_size = __struct_size(p); + const size_t p_size = __struct_size(p); if (__compiletime_lessthan(p_size, size)) __read_overflow(); @@ -693,7 +693,7 @@ extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kme __realloc_size(2); __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp) { - size_t p_size = __struct_size(p); + const size_t p_size = __struct_size(p); if (__compiletime_lessthan(p_size, size)) __read_overflow(); @@ -720,8 +720,8 @@ __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp __FORTIFY_INLINE __diagnose_as(__builtin_strcpy, 1, 2) char *strcpy(char * const POS p, const char * const POS q) { - size_t p_size = __member_size(p); - size_t q_size = __member_size(q); + const size_t p_size = __member_size(p); + const size_t q_size = __member_size(q); size_t size; /* If neither buffer size is known, immediately give up. */
The sizes reported by __member_size should never change in a given function. Mark them as such. Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/fortify-string.h | 42 +++++++++++++++++----------------- 1 file changed, 21 insertions(+), 21 deletions(-)