6.6-stable review patch. If anyone has any objections, please let me know.
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From: Andrey Konovalov andreyknvl@gmail.com
[ Upstream commit 2e577732e8d28b9183df701fb90cb7943aa4ed16 ]
After commit 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") and the follow-up fixes, with CONFIG_FORTIFY_SOURCE enabled, even though the compiler instruments meminstrinsics by generating calls to __asan/__hwasan_ prefixed functions, FORTIFY_SOURCE still uses uninstrumented memset/memmove/memcpy as the underlying functions.
As a result, KASAN cannot detect bad accesses in memset/memmove/memcpy. This also makes KASAN tests corrupt kernel memory and cause crashes.
To fix this, use __asan_/__hwasan_memset/memmove/memcpy as the underlying functions whenever appropriate. Do this only for the instrumented code (as indicated by __SANITIZE_ADDRESS__).
Link: https://lkml.kernel.org/r/20240517130118.759301-1-andrey.konovalov@linux.dev Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Fixes: 51287dcb00cc ("kasan: emit different calls for instrumentable memintrinsics") Fixes: 36be5cba99f6 ("kasan: treat meminstrinsic as builtins in uninstrumented files") Signed-off-by: Andrey Konovalov andreyknvl@gmail.com Reported-by: Erhard Furtner erhard_f@mailbox.org Reported-by: Nico Pache npache@redhat.com Closes: https://lore.kernel.org/all/20240501144156.17e65021@outsider.home/ Reviewed-by: Marco Elver elver@google.com Tested-by: Nico Pache npache@redhat.com Acked-by: Nico Pache npache@redhat.com Cc: Alexander Potapenko glider@google.com Cc: Andrey Ryabinin ryabinin.a.a@gmail.com Cc: Daniel Axtens dja@axtens.net Cc: Dmitry Vyukov dvyukov@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/fortify-string.h | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index da51a83b28293..f7e1895367fa1 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -31,17 +31,30 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning(" __ret; \ })
-#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) +#if defined(__SANITIZE_ADDRESS__) + +#if !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX) && !defined(CONFIG_GENERIC_ENTRY) +extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); +extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); +extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); +#elif defined(CONFIG_KASAN_GENERIC) +extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(__asan_memset); +extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(__asan_memmove); +extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(__asan_memcpy); +#else /* CONFIG_KASAN_SW_TAGS */ +extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(__hwasan_memset); +extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(__hwasan_memmove); +extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(__hwasan_memcpy); +#endif + extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr); extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp); -extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); -extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); -extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat); extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy); extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen); extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat); extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy); + #else
#if defined(__SANITIZE_MEMORY__) @@ -66,6 +79,7 @@ extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) #define __underlying_strlen __builtin_strlen #define __underlying_strncat __builtin_strncat #define __underlying_strncpy __builtin_strncpy + #endif
/**