Re: [PATCH 1/3] IMA: move read/write counters into struct inode

From: John Stoffel
Date: Wed Oct 20 2010 - 10:10:53 EST


>>>>> "Al" == Al Viro <viro@xxxxxxxxxxxxxxxxxx> writes:

Al> On Wed, Oct 20, 2010 at 09:10:27AM -0400, John Stoffel wrote:
>> Does this mean I can't replace /bin/sh on a running system using IMA
>> at all, even if just one process has it opened and is running? So how
>> the hell am I supposed to do live upgrades on a system?

Al> rename(2). Prohibition against write(2) to binary being executed is
Al> *old*. Try to do the following:
Al> cp /bin/sh /tmp
Al> /tmp/sh &
Al> cat /bin/ls >/tmp/sh
Al> and you'll get
Al> sh: /tmp/sh: Text file busy

Al> That has nothing to do with IMA...

Duh, makes sense. Thanks for educating me. I still IMA is a waste of
system resources...

John
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