Re: [syzbot] [hfs?] WARNING in hfs_write_inode

From: Matthew Wilcox
Date: Thu Jul 20 2023 - 13:30:40 EST


On Thu, Jul 20, 2023 at 05:27:57PM +0200, Dmitry Vyukov wrote:
> On Thu, 5 Jan 2023 at 17:45, Viacheslav Dubeyko <slava@xxxxxxxxxxx> wrote:
> > > On Wed, Jan 04, 2023 at 08:37:16PM -0800, Viacheslav Dubeyko wrote:
> > >> Also, as far as I can see, available volume in report (mount_0.gz) somehow corrupted already:
> > >
> > > Syzbot generates deliberately-corrupted (aka fuzzed) filesystem images.
> > > So basically, you can't trust anything you read from the disc.
> > >
> >
> > If the volume has been deliberately corrupted, then no guarantee that file system
> > driver will behave nicely. Technically speaking, inode write operation should never
> > happened for corrupted volume because the corruption should be detected during
> > b-tree node initialization time. If we would like to achieve such nice state of HFS/HFS+
> > drivers, then it requires a lot of refactoring/implementation efforts. I am not sure that
> > it is worth to do because not so many guys really use HFS/HFS+ as the main file
> > system under Linux.
>
>
> Most popular distros will happily auto-mount HFS/HFS+ from anything
> inserted into USB (e.g. what one may think is a charger). This creates
> interesting security consequences for most Linux users.
> An image may also be corrupted non-deliberately, which will lead to
> random memory corruptions if the kernel trusts it blindly.

Then we should delete the HFS/HFS+ filesystems. They're orphaned in
MAINTAINERS and if distros are going to do such a damnfool thing,
then we must stop them.