[NET_SCHED]: act_ipt: fix regression in ipt action

The x_tables patch broke target module autoloading in the ipt action
by replacing the ipt_find_target call (which does autoloading) by
xt_find_target (which doesn't do autoloading). Additionally xt_find_target
may return ERR_PTR values in case of an error, which are not handled.

Use xt_request_find_target, which does both autoloading and ERR_PTR
handling properly. Also don't forget to drop the target module reference
again when xt_check_target fails.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 3 deletions

diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index a9608064a4c3..01e69138578d 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -55,7 +55,8 @@ static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int
         struct ipt_target *target;
         int ret = 0;
 
-        target = xt_find_target(AF_INET, t->u.user.name, t->u.user.revision);
+        target = xt_request_find_target(AF_INET, t->u.user.name,
+                                        t->u.user.revision);
         if (!target)
                 return -ENOENT;
 
@@ -63,9 +64,10 @@ static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int
 
         ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
                               table, hook, 0, 0);
-        if (ret)
+        if (ret) {
+                module_put(t->u.kernel.target->me);
                 return ret;
-
+        }
         if (t->u.kernel.target->checkentry
             && !t->u.kernel.target->checkentry(table, NULL,
                                                t->u.kernel.target, t->data,