[RESEND,2/2] net: Use ns_capable_noaudit() when determining net sysctl permissions
diff mbox

Message ID 1464929002-6624-3-git-send-email-tyhicks@canonical.com
State New
Headers show

Commit Message

Tyler Hicks June 3, 2016, 4:43 a.m. UTC
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>
---
 net/sysctl_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

James Morris June 6, 2016, 9:51 a.m. UTC | #1
On Thu, 2 Jun 2016, Tyler Hicks wrote:

> 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>

Both applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git next

Patch
diff mbox

diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index ed98c1f..46a71c7 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -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;