Re: question about /proc/<PID>/mem in 2.4

[Tigran Aivazian]

On Mon, 5 Jul 2004, FabF wrote:
> > Surely, the super user (i.e. CAP_SYS_PTRACE in this context) should be 
> > allowed to read any process' memory without having to do the 
> > PTRACE_ATTACH/PTRACE_PEEKUSER kind of thing which strace(8) is doing?
> 
> FYI may_ptrace_attach plugged somewhere between 2.4.21 & 22.This one get
> used as is (ie without MAY_PTRACE) in proc_pid_environ but dunno about
> reason why CAP_SYS_PTRACE isn't authoritative elsewhere.

Ok, but still nobody seems to know why the super user is not allowed to
access /proc/<PID>/mem of any task. Any code which nobody in the world
knows the reason for, is broken and should be removed.

I will wait a few weeks to see if someone does come up with the reason for
that "extra secure" check in mem_read() and if nobody has objections I'll
send Linus a patch to relax the check to a more reasonable one, namely to
allow CAP_SYS_PTRACE process to bypass any other conditions imposed.

Kind regards
Tigran

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