Re: BUG: KASAN lib/test_kasan.c

From: Marco Elver
Date: Fri Dec 04 2020 - 15:30:47 EST


On Fri, 4 Dec 2020 at 19:56, Jeffrin Jose T <jeffrin@xxxxxxxxxxxxxxxxxxx> wrote:
> hello,
>
> detected KASAN BUG
>
> [ related information ]
>
> -------------------x-------------------x------------------------>
> [ 43.616259] BUG: KASAN: vmalloc-out-of-bounds in
> vmalloc_oob+0x146/0x2c0
>
> (gdb) l *vmalloc_oob+0x146/0x2c0
> 0xffffffff81b8b0b0 is in vmalloc_oob (lib/test_kasan.c:764).

This is the KASAN test. It's a feature, not a bug. ;-)

> 759 kfree_sensitive(ptr);
> 760 KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
> 761 }
> 762
> 763 static void vmalloc_oob(struct kunit *test)
> 764 {
> 765 void *area;
> 766
> 767 if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
> 768 kunit_info(test, "CONFIG_KASAN_VMALLOC is not
> enabled.");
> (gdb) l *vmalloc_oob+0x146
> 0xffffffff81b8b1f6 is in vmalloc_oob (lib/test_kasan.c:779).
> 774 * The MMU will catch that and crash us.
> 775 */
> 776 area = vmalloc(3000);
> 777 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, area);
> 778
> 779 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char
> *)area)[3100]);
> 780 vfree(area);
> 781 }
> 782
> 783 static struct kunit_case kasan_kunit_test_cases[] = {
> ----------------x-----------------------------x-------------------->
>
> Reported by: Jeffrin Jose T <jeffrin@xxxxxxxxxxxxxxxxxxx>

Which CI system is reporting these?

If you look, this is the KASAN test, and the report is very much
intended since it's testing KASAN. Please blacklist the KASAN test
(and any other tests testing debugging tools).

Thanks,
-- Marco