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>

7 files changed, 5 insertions, 13 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 8cbfaa687d72..fe81c851ca88 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/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;
         }
diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 049eaf12aaab..1f23e048f077 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/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);
diff --git a/drivers/staging/pohmelfs/config.c b/drivers/staging/pohmelfs/config.c
index 89279ba1b737..39413b7d387d 100644
--- a/drivers/staging/pohmelfs/config.c
+++ b/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) {
diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c
index 52ec0959d462..5180a215d781 100644
--- a/drivers/video/uvesafb.c
+++ b/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)
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 66823b862022..4c4ac3f3ce5a 100644
--- a/include/linux/netlink.h
+++ b/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))
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 97ecd923d7ee..a808fb1e877d 100644
--- a/net/netlink/af_netlink.c
+++ b/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);
diff --git a/security/commoncap.c b/security/commoncap.c
index 64c2ed9c9015..a83e607d91c3 100644
--- a/security/commoncap.c
+++ b/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;
 }