diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2019-04-03 09:40:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-04-03 11:02:24 +0200 |
| commit | d08965a27e84ca090b504844d50c24fc98587b11 (patch) | |
| tree | c89c3883246d70a6e9ef5bc16200c763c8dc0071 | |
| parent | 57b78a62e7f23c4686fe54091cdc3d12e60d6513 (diff) | |
x86/uaccess, ubsan: Fix UBSAN vs. SMAP
UBSAN can insert extra code in random locations; including AC=1
sections. Typically this code is not safe and needs wrapping.
So far, only __ubsan_handle_type_mismatch* have been observed in AC=1
sections and therefore only those are annotated.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/ubsan.c | 4 |
2 files changed, 5 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile index 3b08673e8881..c4563e7c47ba 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -268,6 +268,7 @@ obj-$(CONFIG_UCS2_STRING) += ucs2_string.o obj-$(CONFIG_UBSAN) += ubsan.o UBSAN_SANITIZE_ubsan.o := n +CFLAGS_ubsan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) obj-$(CONFIG_SBITMAP) += sbitmap.o diff --git a/lib/ubsan.c b/lib/ubsan.c index e4162f59a81c..c8e905bfb627 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <linux/types.h> #include <linux/sched.h> +#include <linux/uaccess.h> #include "ubsan.h" @@ -313,6 +314,7 @@ static void handle_object_size_mismatch(struct type_mismatch_data_common *data, static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data, unsigned long ptr) { + unsigned long flags = user_access_save(); if (!ptr) handle_null_ptr_deref(data); @@ -320,6 +322,8 @@ static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data, handle_misaligned_access(data, ptr); else handle_object_size_mismatch(data, ptr); + + user_access_restore(flags); } void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, |