From 42855f588e187a6f22978e54422adbc010ac7630 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Mon, 24 Oct 2022 23:21:41 +0200 Subject: x86/purgatory: disable KMSAN instrumentation The stand-alone purgatory.ro does not contain the KMSAN runtime, therefore it can't be built with KMSAN compiler instrumentation. Link: https://lkml.kernel.org/r/20221024212144.2852069-2-glider@google.com Link: https://github.com/google/kmsan/issues/89 Signed-off-by: Alexander Potapenko Cc: Andrew Morton Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Andrew Morton --- arch/x86/purgatory/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 58a200dc762d..17f09dc26381 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -26,6 +26,7 @@ GCOV_PROFILE := n KASAN_SANITIZE := n UBSAN_SANITIZE := n KCSAN_SANITIZE := n +KMSAN_SANITIZE := n KCOV_INSTRUMENT := n # These are adjustments to the compiler flags used for objects that -- cgit v1.2.3 From 59c8a02e24894e75639bcecc3cb1e768a2792220 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Mon, 24 Oct 2022 23:21:43 +0200 Subject: x86: asm: make sure __put_user_size() evaluates pointer once User access macros must ensure their arguments are evaluated only once if they are used more than once in the macro body. Adding instrument_put_user() to __put_user_size() resulted in double evaluation of the `ptr` argument, which led to correctness issues when performing e.g. unsafe_put_user(..., p++, ...). To fix those issues, evaluate the `ptr` argument of __put_user_size() at the beginning of the macro. Link: https://lkml.kernel.org/r/20221024212144.2852069-4-glider@google.com Fixes: 888f84a6da4d ("x86: asm: instrument usercopy in get_user() and put_user()") Signed-off-by: Alexander Potapenko Reported-by: youling257 Cc: Borislav Petkov Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- arch/x86/include/asm/uaccess.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 8bc614cfe21b..1cc756eafa44 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -254,24 +254,25 @@ extern void __put_user_nocheck_8(void); #define __put_user_size(x, ptr, size, label) \ do { \ __typeof__(*(ptr)) __x = (x); /* eval x once */ \ - __chk_user_ptr(ptr); \ + __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \ + __chk_user_ptr(__ptr); \ switch (size) { \ case 1: \ - __put_user_goto(__x, ptr, "b", "iq", label); \ + __put_user_goto(__x, __ptr, "b", "iq", label); \ break; \ case 2: \ - __put_user_goto(__x, ptr, "w", "ir", label); \ + __put_user_goto(__x, __ptr, "w", "ir", label); \ break; \ case 4: \ - __put_user_goto(__x, ptr, "l", "ir", label); \ + __put_user_goto(__x, __ptr, "l", "ir", label); \ break; \ case 8: \ - __put_user_goto_u64(__x, ptr, label); \ + __put_user_goto_u64(__x, __ptr, label); \ break; \ default: \ __put_user_bad(); \ } \ - instrument_put_user(__x, ptr, size); \ + instrument_put_user(__x, __ptr, size); \ } while (0) #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT -- cgit v1.2.3 From 78a498c3a227f2ac773a8234b2ce092a4403f2c3 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Mon, 24 Oct 2022 23:21:44 +0200 Subject: x86: fortify: kmsan: fix KMSAN fortify builds Ensure that KMSAN builds replace memset/memcpy/memmove calls with the respective __msan_XXX functions, and that none of the macros are redefined twice. This should allow building kernel with both CONFIG_KMSAN and CONFIG_FORTIFY_SOURCE. Link: https://lkml.kernel.org/r/20221024212144.2852069-5-glider@google.com Link: https://github.com/google/kmsan/issues/89 Signed-off-by: Alexander Potapenko Reported-by: Tamas K Lengyel Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Kees Cook Signed-off-by: Andrew Morton --- arch/x86/include/asm/string_64.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 3b87d889b6e1..888731ccf1f6 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -10,10 +10,13 @@ /* Even with __builtin_ the compiler may decide to use the out of line function. */ +#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY) +#include +#endif + #define __HAVE_ARCH_MEMCPY 1 -#if defined(__SANITIZE_MEMORY__) +#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY) #undef memcpy -void *__msan_memcpy(void *dst, const void *src, size_t size); #define memcpy __msan_memcpy #else extern void *memcpy(void *to, const void *from, size_t len); @@ -21,7 +24,7 @@ extern void *memcpy(void *to, const void *from, size_t len); extern void *__memcpy(void *to, const void *from, size_t len); #define __HAVE_ARCH_MEMSET -#if defined(__SANITIZE_MEMORY__) +#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY) extern void *__msan_memset(void *s, int c, size_t n); #undef memset #define memset __msan_memset @@ -67,7 +70,7 @@ static inline void *memset64(uint64_t *s, uint64_t v, size_t n) } #define __HAVE_ARCH_MEMMOVE -#if defined(__SANITIZE_MEMORY__) +#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY) #undef memmove void *__msan_memmove(void *dest, const void *src, size_t len); #define memmove __msan_memmove -- cgit v1.2.3