netlink: kill eff_cap from struct netlink_skb_parms

Netlink message processing in the kernel is synchronous these days,
capabilities can be checked directly in security_netlink_recv() from
the current process.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Reviewed-by: James Morris <jmorris@namei.org>
[chrisw: update to include pohmelfs and uvesafb]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/block/drbd/drbd_nl.c

@@ -2177,7 +2177,7 @@ static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms
 		return;
 	}
 
-	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN)) {
+	if (!cap_raised(current_cap(), CAP_SYS_ADMIN)) {
 		retcode = ERR_PERM;
 		goto fail;
 	}

drivers/md/dm-log-userspace-transfer.c

@@ -134,7 +134,7 @@ static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 {
 	struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1);
 
-	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN))
+	if (!cap_raised(current_cap(), CAP_SYS_ADMIN))
 		return;
 
 	spin_lock(&receiving_list_lock);

drivers/staging/pohmelfs/config.c

@@ -525,7 +525,7 @@ static void pohmelfs_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *n
 {
 	int err;
 
-	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN))
+	if (!cap_raised(current_cap(), CAP_SYS_ADMIN))
 		return;
 
 	switch (msg->flags) {

drivers/video/uvesafb.c

@@ -73,7 +73,7 @@ static void uvesafb_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *ns
 	struct uvesafb_task *utask;
 	struct uvesafb_ktask *task;
 
-	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN))
+	if (!cap_raised(current_cap(), CAP_SYS_ADMIN))
 		return;
 
 	if (msg->seq >= UVESAFB_TASKS_MAX)

include/linux/netlink.h

@@ -160,7 +160,6 @@ struct netlink_skb_parms {
 	struct ucred		creds;		/* Skb credentials	*/
 	__u32			pid;
 	__u32			dst_group;
-	kernel_cap_t		eff_cap;
 };
 
 #define NETLINK_CB(skb)		(*(struct netlink_skb_parms*)&((skb)->cb))

net/netlink/af_netlink.c

@@ -1364,12 +1364,6 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	NETLINK_CB(skb).dst_group = dst_group;
 	memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
 
-	/* What can I do? Netlink is asynchronous, so that
-	   we will have to save current capabilities to
-	   check them, when this message will be delivered
-	   to corresponding kernel module.   --ANK (980802)
-	 */
-
 	err = -EFAULT;
 	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
 		kfree_skb(skb);

security/commoncap.c

@@ -52,13 +52,12 @@ static void warn_setuid_and_fcaps_mixed(const char *fname)
 
 int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
 {
-	NETLINK_CB(skb).eff_cap = current_cap();
 	return 0;
 }
 
 int cap_netlink_recv(struct sk_buff *skb, int cap)
 {
-	if (!cap_raised(NETLINK_CB(skb).eff_cap, cap))
+	if (!cap_raised(current_cap(), cap))
 		return -EPERM;
 	return 0;
 }