From: ebiederm@xmission.com (Eric W. Biederman)
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
David Howells <dhowells@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Sasha Levin <levinsasha928@gmail.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Oleg Nesterov <oleg@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH, RESEND] procfs: silence lockdep warning about read vs. exec seq_file
Date: Mon, 04 Aug 2014 20:42:11 -0700 [thread overview]
Message-ID: <87d2cfzjos.fsf@x220.int.ebiederm.org> (raw)
In-Reply-To: <1407010227-2269-1-git-send-email-kirill@shutemov.name> (Kirill A. Shutemov's message of "Sat, 2 Aug 2014 23:10:27 +0300")
"Kirill A. Shutemov" <kirill@shutemov.name> writes:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
>
> Testcase:
>
> cat /proc/self/maps >/dev/null
> chmod +x /proc/self/net/packet
> exec /proc/self/net/packet
>
> It triggers lockdep warning:
> I don't know why we allow "chmod +x" on some proc files, notably net-related.
> Is it a bug?
It looks like we simply did not remove the ability to make those files
executable when we realized executable proc files could be a problem.
I expect that part of proc could use an audit where someone figures out
what makes sense. It does appear that chmod XXX /proc/generic_file
is explicitly supported. So we would have to be delicate with any
changes in that area to avoid creating userspace regressions.
Eric
next prev parent reply other threads:[~2014-08-05 3:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-02 20:10 [PATCH, RESEND] procfs: silence lockdep warning about read vs. exec seq_file Kirill A. Shutemov
2014-08-03 16:44 ` Oleg Nesterov
2014-08-03 21:18 ` [PATCH 0/5] (Was: procfs: silence lockdep warning about read vs. exec seq_file) Oleg Nesterov
2014-08-03 21:19 ` [PATCH 1/5] fs/proc/task_mmu.c: don't use task->mm in m_start() and show_*map() Oleg Nesterov
2014-08-03 21:19 ` [PATCH 2/5] fs/proc/task_mmu.c: unify/simplify do_maps_open() and numa_maps_open() Oleg Nesterov
2014-08-03 21:20 ` [PATCH 3/5] proc: introduce proc_mem_open() Oleg Nesterov
2014-08-03 21:20 ` [PATCH 4/5] fs/proc/task_mmu.c: introduce the "stable" proc_maps_private->mm Oleg Nesterov
2014-08-03 21:20 ` [PATCH 5/5] fs/proc/task_mmu.c: change m_start() to rely on priv->mm and avoid mm_access() Oleg Nesterov
2014-08-04 6:59 ` [PATCH 0/5] (Was: procfs: silence lockdep warning about read vs. exec seq_file) Cyrill Gorcunov
2014-08-04 9:20 ` Kirill A. Shutemov
2014-08-04 14:55 ` Oleg Nesterov
2014-08-05 3:42 ` Eric W. Biederman [this message]
2014-08-05 8:46 ` [PATCH, RESEND] procfs: silence lockdep warning about read vs. exec seq_file Kirill A. Shutemov
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