Re: KASAN: null-ptr-deref Read in PageHuge

[Matthew Wilcox]

On Fri, Sep 18, 2020 at 12:42:24PM -0700, Mike Kravetz wrote:
> On 9/18/20 4:02 AM, syzbot wrote:
> > ==================================================================
> > BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
> > BUG: KASAN: null-ptr-deref in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
> > BUG: KASAN: null-ptr-deref in PageCompound include/linux/page-flags.h:196 [inline]
> > BUG: KASAN: null-ptr-deref in PageHuge+0x19/0x170 mm/hugetlb.c:1551
> > Read of size 8 at addr 0000000000000000 by task syz-executor410/6864
> > 
> 
> I assume this would also be fixed by 5d1903f712ac
> ("mm-convert-find_get_entry-to-return-the-head-page-fix")

That's a good bet.