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Subject: Re: [syzbot] [hfs?] WARNING in hfs_write_inode
From:   Viacheslav Dubeyko <slava@dubeyko.com>
In-Reply-To: <Y7bw7X1Y5KtmPF5s@casper.infradead.org>
Date:   Thu, 5 Jan 2023 08:45:31 -0800
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        syzbot <syzbot+7bb7cd3595533513a9e7@syzkaller.appspotmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        christian.brauner@ubuntu.com,
        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Jeff Layton <jlayton@kernel.org>,
        Linux FS Devel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller-bugs@googlegroups.com,
        ZhangPeng <zhangpeng362@huawei.com>,
        linux-m68k@lists.linux-m68k.org
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To:     Matthew Wilcox <willy@infradead.org>
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> On Jan 5, 2023, at 7:46 AM, Matthew Wilcox <willy@infradead.org> =
wrote:
>=20
> 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:
>=20
> Syzbot generates deliberately-corrupted (aka fuzzed) filesystem =
images.
> So basically, you can't trust anything you read from the disc.
>=20

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.

Thanks,
Slava.