[PATCH][netfilter] Avoid a possible NULL pointer deref in recent_seq_open()

[Jesper Juhl <jesper.juhl@gmail.com>]

EHLO,

There is a small problem in
 net/ipv4/netfilter/ipt_recent.c::recent_seq_open().

If the call to seq_open() returns != 0 then the code calls 
kfree(st) but then on the very next line proceeds to 
dereference the pointer - not good.

Problem spotted by the Coverity checker.

Proposed patch to deal with it below.

Compile tested only.


Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
---

 net/ipv4/netfilter/ipt_recent.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/netfilter/ipt_recent.c b/net/ipv4/netfilter/ipt_recent.c
index 3218043..6d0c0f7 100644
--- a/net/ipv4/netfilter/ipt_recent.c
+++ b/net/ipv4/netfilter/ipt_recent.c
@@ -387,12 +387,17 @@ static int recent_seq_open(struct inode *inode, struct file *file)
 	st = kzalloc(sizeof(*st), GFP_KERNEL);
 	if (st == NULL)
 		return -ENOMEM;
+
 	ret = seq_open(file, &recent_seq_ops);
-	if (ret)
+	if (ret) {
 		kfree(st);
+		goto out;
+	}
+
 	st->table    = pde->data;
 	seq          = file->private_data;
 	seq->private = st;
+out:
 	return ret;
 }