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Date: Wed, 15 May 2024 18:13:14 +0200
From: David Sterba <dsterba@suse.cz>
To: syzbot <syzbot+c92c93d1f1aaaacdb9db@syzkaller.appspotmail.com>
Cc: axboe@kernel.dk, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, maz@kernel.org, oleg@redhat.com,
	peterz@infradead.org, syzkaller-bugs@googlegroups.com,
	viro@zeniv.linux.org.uk
Subject: Re: kernel BUG at fs/inode.c:LINE! (2)
Message-ID: <20240515161314.GO4449@twin.jikos.cz>
Reply-To: dsterba@suse.cz
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On Fri, Aug 28, 2020 at 06:18:17AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    d012a719 Linux 5.9-rc2
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15aa650e900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=891ca5711a9f1650
> dashboard link: https://syzkaller.appspot.com/bug?extid=c92c93d1f1aaaacdb9db
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12ecb939900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=140a19a9900000
> 
> The issue was bisected to:
> 
> commit a9ed4a6560b8562b7e2e2bed9527e88001f7b682
> Author: Marc Zyngier <maz@kernel.org>
> Date:   Wed Aug 19 16:12:17 2020 +0000
> 
>     epoll: Keep a reference on files added to the check list
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16a50519900000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=15a50519900000
> console output: https://syzkaller.appspot.com/x/log.txt?x=11a50519900000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+c92c93d1f1aaaacdb9db@syzkaller.appspotmail.com
> Fixes: a9ed4a6560b8 ("epoll: Keep a reference on files added to the check list")
> 
> ------------[ cut here ]------------
> kernel BUG at fs/inode.c:1668!

#syz set subsystem: fs

This has been among btrfs bugs but this is is 'fs' and probably with a
fix but I was not able to identify it among all the changes in
eventpoll.c