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>
diff --git a/lib/ubsan.c b/lib/ubsan.c
index e4162f5..c8e905b 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,