From: David Laight <David.Laight@ACULAB.COM>
To: David Laight <David.Laight@ACULAB.COM>,
'syzbot' <syzbot+51177e4144d764827c45@syzkaller.appspotmail.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"syzkaller-bugs@googlegroups.com"
<syzkaller-bugs@googlegroups.com>,
"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>
Subject: RE: WARNING in __kernel_read (2)
Date: Sat, 26 Sep 2020 13:17:04 +0000 [thread overview]
Message-ID: <642ed0b4810d44ab97a7832ccb8b3e44@AcuMS.aculab.com> (raw)
In-Reply-To: <3b3de066852d4e30bd9d85bd28023100@AcuMS.aculab.com>
From: David Laight
> Sent: 26 September 2020 12:16
> To: 'syzbot' <syzbot+51177e4144d764827c45@syzkaller.appspotmail.com>; linux-fsdevel@vger.kernel.org;
> linux-kernel@vger.kernel.org; syzkaller-bugs@googlegroups.com; viro@zeniv.linux.org.uk
> Subject: RE: WARNING in __kernel_read (2)
>
> > From: syzbot <syzbot+51177e4144d764827c45@syzkaller.appspotmail.com>
> > Sent: 26 September 2020 03:58
> > To: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; syzkaller-bugs@googlegroups.com;
> > viro@zeniv.linux.org.uk
> > Subject: WARNING in __kernel_read (2)
>
> I suspect this is calling finit_module() on an fd
> that doesn't have read permissions.
Code inspection also seems to imply that the check means
the exec() also requires read permissions on the file.
This isn't traditionally true.
suid #! scripts are particularly odd without 'owner read'
(everyone except the owner can run them!).
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-09-26 13:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-26 2:58 WARNING in __kernel_read (2) syzbot
2020-09-26 11:15 ` David Laight
2020-09-26 13:17 ` David Laight [this message]
2020-09-28 22:14 ` Eric Biggers
2020-09-29 6:38 ` Christoph Hellwig
2020-09-29 6:46 ` Eric Biggers
2020-09-29 6:56 ` Christoph Hellwig
2020-09-29 8:06 ` David Laight
2020-09-29 8:21 ` Dmitry Vyukov
2020-09-29 10:21 ` Christoph Hellwig
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