Re: general protection fault in ext4_writepages

From: Theodore Y. Ts'o
Date: Mon Nov 11 2019 - 13:24:29 EST


On Mon, Nov 11, 2019 at 11:02:31AM +0530, Ritesh Harjani wrote:
>
> Updating the link.
>
> On 11/11/19 10:42 AM, Ritesh Harjani wrote:
> > Hello Ted,
> >
> > This issue seems to be coming via fault injection failure in slab
> > allocation. This should be fixed via below patch on your latest ext4
> > branch.
> >
> > https://marc.info/?l=linux-ext4&m=804&w=2
> https://marc.info/?l=linux-ext4&m=157303310723804&w=2

Agreed, although unfortunately I wasn't able to make the reproducer
cause a failure _without_ the patch. Perhaps something other than
enabling FAILSLAB and KASAN was needed?

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git test

Let's see if the Syzbot can confirm that the patch addresses the problem.

- Ted