The patch titled
Subject: kasan, fortify: properly rename memintrinsics
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kasan-fortify-properly-rename-memintrinsics.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-fortify-properly-rename-memintrinsics.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Subject: kasan, fortify: properly rename memintrinsics
Date: Fri, 17 May 2024 15:01:18 +0200
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@xxxxxxxxx
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@xxxxxxxxx>
Reported-by: Erhard Furtner <erhard_f@xxxxxxxxxxx>
Reported-by: Nico Pache <npache@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/20240501144156.17e65021@xxxxxxxxxxxxx/
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Tested-by: Nico Pache <npache@xxxxxxxxxx>
Acked-by: Nico Pache <npache@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Daniel Axtens <dja@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/fortify-string.h | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
--- a/include/linux/fortify-string.h~kasan-fortify-properly-rename-memintrinsics
+++ a/include/linux/fortify-string.h
@@ -75,17 +75,30 @@ void __write_overflow_field(size_t avail
__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__)
@@ -110,6 +123,7 @@ extern char *__underlying_strncpy(char *
#define __underlying_strlen __builtin_strlen
#define __underlying_strncat __builtin_strncat
#define __underlying_strncpy __builtin_strncpy
+
#endif
/**
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxx are
kasan-fortify-properly-rename-memintrinsics.patch
