x86/uaccess, ubsan: Fix UBSAN vs. SMAP (d08965a2) · Commits · 戴 / test

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>

lib/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

lib/ubsan.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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,

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