mm/kasan: don't use kasan shadow pointer in generic functions (f2377d4e) · Commits · 戴 / test

We can't use generic functions like print_hex_dump to access kasan shadow region. This require us to setup another kasan shadow region for the address passed (kasan shadow address). Some architectures won't be able to do that. Hence make a copy of the shadow region row and pass that to generic functions. Signed-off-by:

Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by:

Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/report.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -164,14 +164,20 @@ static void print_shadow_for_address(const void *addr)
		for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) {
		const void *kaddr = kasan_shadow_to_mem(shadow_row);
		char buffer[4 + (BITS_PER_LONG/8)*2];
		char shadow_buf[SHADOW_BYTES_PER_ROW];

		snprintf(buffer, sizeof(buffer),
		(i == 0) ? ">%p: " : " %p: ", kaddr);

		/*
		* We should not pass a shadow pointer to generic
		* function, because generic functions may try to
		* access kasan mapping for the passed address.
		*/
		kasan_disable_current();
		memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW);
		print_hex_dump(KERN_ERR, buffer,
		DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1,
		shadow_row, SHADOW_BYTES_PER_ROW, 0);
		shadow_buf, SHADOW_BYTES_PER_ROW, 0);
		kasan_enable_current();

		if (row_is_guilty(shadow_row, shadow))

Admin message