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Date:   Mon, 11 Nov 2019 13:24:17 -0500
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Ritesh Harjani <riteshh@linux.ibm.com>
Cc:     syzbot <syzbot+9567fda428fba259deba@syzkaller.appspotmail.com>,
        adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        Jan Kara <jack@suse.cz>
Subject: Re: general protection fault in ext4_writepages
Message-ID: <20191111182417.GB5165@mit.edu>
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 <20191111051236.2717D11C05B@d06av25.portsmouth.uk.ibm.com>
 <20191111053231.F129B11C04C@d06av25.portsmouth.uk.ibm.com>
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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