shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-03-24 19:40:21 +09:00
Code Issues Packages Projects Releases Wiki Activity

ipc: Restrict mounting the mqueue filesystem

Browse Source 
commit a636b702ed upstream.

Only allow mounting the mqueue filesystem if the caller has CAP_SYS_ADMIN
rights over the ipc namespace.   The principle here is if you create
or have capabilities over it you can mount it, otherwise you get to live
with what other people have mounted.

This information is not particularly sensitive and mqueue essentially
only reports which posix messages queues exist.  Still when creating a
restricted environment for an application to live any extra
information may be of use to someone with sufficient creativity.  The
historical if imperfect way this information has been restricted has
been not to allow mounts and restricting this to ipc namespace
creators maintains the spirit of the historical restriction.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric W. Biederman
2013-03-21 18:13:15 -07:00
committed by Greg Kroah-Hartman
parent 9c773201d6
commit 63795cc597
1 changed files with 10 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
ipc/mqueue.c
View File

@@ -330,8 +330,16 @@ static struct dentry *mqueue_mount(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
if (!(flags & MS_KERNMOUNT))
data = current->nsproxy->ipc_ns;
if (!(flags & MS_KERNMOUNT)) {
struct ipc_namespace *ns = current->nsproxy->ipc_ns;
/* Don't allow mounting unless the caller has CAP_SYS_ADMIN
* over the ipc namespace.
*/
if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
data = ns;
}
return mount_ns(fs_type, flags, data, mqueue_fill_super);
}