Mailing List Archive

[NETFILTER]: ipt_recent: avoid a possible NULL pointer deref in 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>
Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit ab3b4927a235c95684cb571b90a04cf6ea1ef7f9
tree acdb734e5cd9dfc4d471ccd85c84cb80100ed45d
parent b880c0879b449ace25e8454656fb0646b32634e6
author Jesper Juhl <jesper.juhl@gmail.com> Mon, 06 Aug 2007 14:09:52 +0200
committer Patrick McHardy <kaber@trash.net> Mon, 06 Aug 2007 14:09:52 +0200

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;
}