net: Use ns_capable_noaudit() when determining net sysctl permissions

The capability check should not be audited since it is only being used
to determine the inode permissions. A failed check does not indicate a
violation of security policy but, when an LSM is enabled, a denial audit
message was being generated.

The denial audit message caused confusion for some application authors
because root-running Go applications always triggered the denial. To
prevent this confusion, the capability check in net_ctl_permissions() is
switched to the noaudit variant.

BugLink: https://launchpad.net/bugs/1465724

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This commit is contained in:
Tyler Hicks 2016-06-02 23:43:22 -05:00 committed by James Morris
parent 98f368e9e2
commit d6e0d30644

View File

@ -46,7 +46,7 @@ static int net_ctl_permissions(struct ctl_table_header *head,
kgid_t root_gid = make_kgid(net->user_ns, 0);
/* Allow network administrator to have same access as root. */
if (ns_capable(net->user_ns, CAP_NET_ADMIN) ||
if (ns_capable_noaudit(net->user_ns, CAP_NET_ADMIN) ||
uid_eq(root_uid, current_euid())) {
int mode = (table->mode >> 6) & 7;
return (mode << 6) | (mode << 3) | mode;