net-2.6 [Bug-Fix][dccp]: fix oops caused after failed initialisation

dccp: fix panic caused by failed initialisation

This fixes a kernel panic reported thanks to Andre Noll:

if DCCP is compiled into the kernel and any out of the initialisation
steps in net/dccp/proto.c:dccp_init() fail, a subsequent attempt to create
a SOCK_DCCP socket will panic, since inet{,6}_create() are not prevented
from creating DCCP sockets.

This patch fixes the problem by propagating a failure in dccp_init() to
dccp_v{4,6}_init_net(), and from there to dccp_v{4,6}_init(), so that the
DCCP protocol is not made available if its initialisation fails.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index b195c4feaa0a..4071eaf2b361 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -998,11 +998,11 @@ static struct inet_protosw dccp_v4_protosw = {
 
 static int __net_init dccp_v4_init_net(struct net *net)
 {
-        int err;
+        if (dccp_hashinfo.bhash == NULL)
+                return -ESOCKTNOSUPPORT;
 
-        err = inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
-                                   SOCK_DCCP, IPPROTO_DCCP, net);
-        return err;
+        return inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
+                                    SOCK_DCCP, IPPROTO_DCCP, net);
 }
 
 static void __net_exit dccp_v4_exit_net(struct net *net)