From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
MIME-Version: 1.0
References: <CAE5jQCfP1Z0oTBz_V0QkFwFqtJgekUMD2HZR=qA2oWxPvZrzsQ@mail.gmail.com>
 <20180603184955.zrowxp4y3ij66y5n@eaf> <20180608152557.GB11958@amd>
 <CAE5jQCeCOK5zoH4KbyP+hiMKp4MpkjJN1efzquoXCfPPXoj9Nw@mail.gmail.com> <20180709203455.fbmx45ehrsj6yjzr@eaf>
In-Reply-To: <20180709203455.fbmx45ehrsj6yjzr@eaf>
From: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Date: Tue, 10 Jul 2018 20:28:37 +0300
Message-ID: <CAE5jQCd0dD2jcNLGXK0N1g6TOfNfruyTV-7R6Eh1v65bkoqi1g@mail.gmail.com>
Subject: Re: Mounting corrupted HFS+ causes kernel NULL pointer dereference
To: "Ernesto A. Fernandez" <ernesto.mnd.fernandez@gmail.com>
Cc: pavel@ucw.cz, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

Thank you,

When applied this single patch on v4.18-rc4 and performed "echo >
/mnt/xyz" on hfsplus_16mb_hang image, I get about 14 pairs of lines

hfsplus: unable to mark blocks free: error -5
hfsplus: can't free extent

Then `echo` exits with "No space left on device" error. Then it
permits to perform `rm /mnt/xyz` and on `echo > /mnt/1` it responds
with no space left on device (but file *is* created and is cattable).
I don't know what is safer, but now it doesn't deadlock. :) Maybe it
is even worth to remount FS r/o, I don't know. (Please excuse me for
speculations)

Thanks,
Anatoly

=D0=BF=D0=BD, 9 =D0=B8=D1=8E=D0=BB. 2018 =D0=B3. =D0=B2 23:35, Ernesto A. F=
ern=C3=A1ndez
<ernesto.mnd.fernandez@gmail.com>:
>
> On Tue, Jun 12, 2018 at 09:43:26PM +0300, Anatoly Trosinenko wrote:
> > And when I mount hfsplus_16mb_hang and perform `echo > /mnt/xyz`, it ha=
ngs.
>
> I just sent you a patch for this final report. Let me know if it works
> for you.