Re: [PATCH 0/2] finx argv_split() vs sysctl race

From: Andi Kleen
Date: Sat Mar 16 2013 - 16:32:34 EST


On Sat, Mar 16, 2013 at 09:23:27PM +0100, Oleg Nesterov wrote:
> On 03/15, Oleg Nesterov wrote:
> >
> > To remind, say, argv_split(poweroff_cmd) can race with sysctl changing this
> > string, in this case it can write to the memory after argv[] array. We can
> > fix this, or we can rewrite argv_split/free:
>
> OK, please see 1/2.
>
> And this reminds me about set_task_comm() which pretends it does something
> meaningful for the reader of the mutable ->comm, see the offtopic 2/2.

I had "rcu strings" to handle the sysctl string race problem in a
generic way some time ago.

http://lwn.net/Articles/368684/

Unfortunately never made it in. Perhaps it should be revisited.
In fact I believe the old patchkit fixed the reboot command race.

-andi
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