Re: [PATCH 5/6] proc: use task_access_lock() instead of ptrace_may_access()

From: Cong Wang
Date: Thu Apr 12 2012 - 09:22:36 EST


On 04/11/2012 01:59 PM, Cong Wang wrote:
There are several places in fs/proc/base.c still use ptrace_may_access()
directly to check the permission, actually this just gets a snapshot of
the permission, nothing prevents the target task from raising the priviledges
itself, it is better to use task_access_lock() for these places, to hold
the priviledges.

Hi, Andrew,

Please drop this patch, it introduces a deadlock when execve() a /proc/<pid>/exec file, and it is not a big improvement nor fixes any bugs, so let's just drop this one.

Thanks!
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