Messages in this thread | | | Date | Wed, 18 Apr 2012 03:22:10 +0000 | From | "Serge E. Hallyn" <> | Subject | Re: [Patch 5/8] mqueue: revert bump up DFLT_*MAX |
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Quoting Doug Ledford (dledford@redhat.com): > From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > > Mqueue limitation is slightly naieve parameter likes other ipcs > because unprivileged user can consume kernel memory by using ipcs. > > Thus, too aggressive raise bring us security issue. Example, > current setting allow evil unprivileged user use 256GB (= 256 > * 1024 * 1024*1024) and it's enough large to system will belome > unresponsive. Don't do that. > > Instead, every admin should adjust the knobs for their own systems.
Would you be terribly averse to having a higher limit in init_ipc_ns, and the lower values by default in all child namespaces?
Sorry it sounds from the intro like you've already had quite a bit of discussion on this...
Of course I realize the values can just be raised by distro boot scripts...
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > Acked-by: Doug Ledford <dledford@redhat.com> > Acked-by: Joe Korty <joe.korty@ccur.com> > Cc: Amerigo Wang <amwang@redhat.com> > Cc: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
> Cc: Jiri Slaby <jslaby@suse.cz> > --- > include/linux/ipc_namespace.h | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h > index 6e1dd08..2488535 100644 > --- a/include/linux/ipc_namespace.h > +++ b/include/linux/ipc_namespace.h > @@ -118,12 +118,12 @@ extern int mq_init_ns(struct ipc_namespace *ns); > #define DFLT_QUEUESMAX 256 > #define HARD_QUEUESMAX 1024 > #define MIN_MSGMAX 1 > -#define DFLT_MSG 64U > -#define DFLT_MSGMAX 1024 > +#define DFLT_MSG 10U > +#define DFLT_MSGMAX 10 > #define HARD_MSGMAX 65536 > #define MIN_MSGSIZEMAX 128 > #define DFLT_MSGSIZE 8192U > -#define DFLT_MSGSIZEMAX (1024*1024) > +#define DFLT_MSGSIZEMAX 8192 > #define HARD_MSGSIZEMAX (16*1024*1024) > #else > static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } > -- > 1.7.7.6 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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