[NETLINK]: Don't prevent creating sockets when no kernel socket is registered
This broke the pam audit module which includes an incorrect check for
-ENOENT instead of -EPROTONOTSUPP.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 62435ff..a64e1d5 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -398,24 +398,13 @@
if (nl_table[protocol].registered &&
try_module_get(nl_table[protocol].module))
module = nl_table[protocol].module;
- else
- err = -EPROTONOSUPPORT;
groups = nl_table[protocol].groups;
netlink_unlock_table();
- if (err || (err = __netlink_create(sock, protocol) < 0))
+ if ((err = __netlink_create(sock, protocol) < 0))
goto out_module;
nlk = nlk_sk(sock->sk);
-
- nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
- if (nlk->groups == NULL) {
- err = -ENOMEM;
- goto out_module;
- }
- memset(nlk->groups, 0, NLGRPSZ(groups));
- nlk->ngroups = groups;
-
nlk->module = module;
out:
return err;
@@ -534,6 +523,29 @@
nlk->subscriptions = subscriptions;
}
+static int netlink_alloc_groups(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ unsigned int groups;
+ int err = 0;
+
+ netlink_lock_table();
+ groups = nl_table[sk->sk_protocol].groups;
+ if (!nl_table[sk->sk_protocol].registered)
+ err = -ENOENT;
+ netlink_unlock_table();
+
+ if (err)
+ return err;
+
+ nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
+ if (nlk->groups == NULL)
+ return -ENOMEM;
+ memset(nlk->groups, 0, NLGRPSZ(groups));
+ nlk->ngroups = groups;
+ return 0;
+}
+
static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
struct sock *sk = sock->sk;
@@ -545,8 +557,15 @@
return -EINVAL;
/* Only superuser is allowed to listen multicasts */
- if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_RECV))
- return -EPERM;
+ if (nladdr->nl_groups) {
+ if (!netlink_capable(sock, NL_NONROOT_RECV))
+ return -EPERM;
+ if (nlk->groups == NULL) {
+ err = netlink_alloc_groups(sk);
+ if (err)
+ return err;
+ }
+ }
if (nlk->pid) {
if (nladdr->nl_pid != nlk->pid)
@@ -559,7 +578,7 @@
return err;
}
- if (!nladdr->nl_groups && !(u32)nlk->groups[0])
+ if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
return 0;
netlink_table_grab();
@@ -620,7 +639,7 @@
nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
} else {
nladdr->nl_pid = nlk->pid;
- nladdr->nl_groups = nlk->groups[0];
+ nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
}
return 0;
}
@@ -976,6 +995,11 @@
if (!netlink_capable(sock, NL_NONROOT_RECV))
return -EPERM;
+ if (nlk->groups == NULL) {
+ err = netlink_alloc_groups(sk);
+ if (err)
+ return err;
+ }
if (!val || val - 1 >= nlk->ngroups)
return -EINVAL;
netlink_table_grab();
@@ -1483,8 +1507,7 @@
s,
s->sk_protocol,
nlk->pid,
- nlk->flags & NETLINK_KERNEL_SOCKET ?
- 0 : (unsigned int)nlk->groups[0],
+ nlk->groups ? (u32)nlk->groups[0] : 0,
atomic_read(&s->sk_rmem_alloc),
atomic_read(&s->sk_wmem_alloc),
nlk->cb,