Messages in this thread | | | Date | Thu, 11 Dec 2008 08:59:57 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH 1/1] devices cgroup: allow mkfifo |
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Quoting Li Zefan (lizf@cn.fujitsu.com): > CC: Andrew > > Serge E. Hallyn wrote: > > The devcgroup_inode_permission() hook in the devices whitelist > > cgroup has always bypassed access checks on fifos. But the > > mknod hook did not. The devices whitelist is only about block > > and char devices, and fifos can't even be added to the whitelist, > > so fifos can't be created at all except by tasks which have 'a' > > in their whitelist (meaning they have access to all devices). > > > > Fix the behavior by bypassing access checks to mkfifo. > > > > It also bypasses checks to mksock. Should backport this patch?
Do you mean push it into -stable?
Couldn't hurt, but it's a DOS to root in a container, not a security vulnerability, and since noone has complainted until now so at least it's not panick-worthy.
> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Thanks. I'll go ahead and send to Linus and -stable.
-serge
> > Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> > > --- > > security/device_cgroup.c | 3 +++ > > 1 files changed, 3 insertions(+), 0 deletions(-) > > > > diff --git a/security/device_cgroup.c b/security/device_cgroup.c > > index 5ba7870..df9d491 100644 > > --- a/security/device_cgroup.c > > +++ b/security/device_cgroup.c > > @@ -513,6 +513,9 @@ int devcgroup_inode_mknod(int mode, dev_t dev) > > struct dev_cgroup *dev_cgroup; > > struct dev_whitelist_item *wh; > > > > + if (!S_ISBLK(mode) && !S_ISCHR(mode)) > > + return 0; > > + > > rcu_read_lock(); > > > > dev_cgroup = task_devcgroup(current);
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