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From: Justin Cormack <justin@specialbusservice.com>
To: musl@lists.openwall.com
Subject: unexpected syscall failures
Date: Tue, 16 Apr 2013 09:02:31 +0100	[thread overview]
Message-ID: <CAK4o1WyB+mfLTLvnyroQd6qtppSU9m98=aWVDs8+6FHqfA4ncg@mail.gmail.com> (raw)

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I noticed that in some places we assume some system calls will not fail,
one example being in nice that I was looking at the other day, but there
are others:

return setpriority(PRIO_PROCESS, 0, getpriority(PRIO_PROCESS, 0)+inc);

Now in Linux you can use security frameworks (eg type 2 seccomp) to make
any system call fail. Do we want to program defensively around these cases?
(In the case of seccomp I think most people use it to abort the program not
error, but you can).

I am inclined to think that if someone makes getpid fail they deserve
anything they get. I can't see any security issues, just some potentially
confusing behaviour, eg here nice might succeed (but set errno) if
getpriority fails. But testing does have downsides.

Justin

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             reply	other threads:[~2013-04-16  8:02 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-16  8:02 Justin Cormack [this message]
2013-04-17  1:14 ` Rich Felker

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