From: Gao Feng <fgao@xxxxxxxxxx>
Current xt_osf codes use memcmp to check if two user fingers are same,
so it depends on that the struct xt_osf_user_finger is no padding.
It is one implicit rule, and is not good to maintain.
Now use zero memory and assign the members explicitly.
Signed-off-by: Gao Feng <fgao@xxxxxxxxxx>
---
net/netfilter/xt_osf.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c
index 2455b69..9793670 100644
--- a/net/netfilter/xt_osf.c
+++ b/net/netfilter/xt_osf.c
@@ -61,6 +61,34 @@ static const struct nla_policy xt_osf_policy[OSF_ATTR_MAX + 1] = {
[OSF_ATTR_FINGER] = { .len = sizeof(struct xt_osf_user_finger) },
};
+static void copy_user_finger(struct xt_osf_user_finger *dst,
+ const struct xt_osf_user_finger *src)
+{
+#define OSF_COPY_MEMBER(mem) dst->mem = src->mem
+
+ int i;
+
+ OSF_COPY_MEMBER(wss.wc);
+ OSF_COPY_MEMBER(wss.val);
+
+ OSF_COPY_MEMBER(ttl);
+ OSF_COPY_MEMBER(df);
+ OSF_COPY_MEMBER(ss);
+ OSF_COPY_MEMBER(mss);
+ OSF_COPY_MEMBER(opt_num);
+
+ memcpy(dst->genre, src->genre, sizeof(dst->genre));
+ memcpy(dst->version, src->version, sizeof(dst->version));
+ memcpy(dst->subtype, src->subtype, sizeof(dst->subtype));
+
+ for (i = 0; i < MAX_IPOPTLEN; ++i) {
+ OSF_COPY_MEMBER(opt[i].kind);
+ OSF_COPY_MEMBER(opt[i].length);
+ OSF_COPY_MEMBER(opt[i].wc.wc);
+ OSF_COPY_MEMBER(opt[i].wc.val);
+ }
+}
+
static int xt_osf_add_callback(struct net *net, struct sock *ctnl,
struct sk_buff *skb, const struct nlmsghdr *nlh,
const struct nlattr * const osf_attrs[])
@@ -77,11 +105,11 @@ static int xt_osf_add_callback(struct net *net, struct sock *ctnl,
f = nla_data(osf_attrs[OSF_ATTR_FINGER]);
- kf = kmalloc(sizeof(struct xt_osf_finger), GFP_KERNEL);
+ kf = kzalloc(sizeof(*kf), GFP_KERNEL);
if (!kf)
return -ENOMEM;
- memcpy(&kf->finger, f, sizeof(struct xt_osf_user_finger));
+ copy_user_finger(&kf->finger, f);
list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) {
if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))
--
1.9.1
--
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