net: ieee802154: 6lowpan: fix frag reassembly

commit f18fa5de5ba7f1d6650951502bb96a6e4715a948 upstream.

This patch initialize stack variables which are used in
frag_lowpan_compare_key to zero. In my case there are padding bytes in the
structures ieee802154_addr as well in frag_lowpan_compare_key. Otherwise
the key variable contains random bytes. The result is that a compare of
two keys by memcmp works incorrect.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Reported-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
index 3c5fc06..fdbebe5 100644 (file)
--- a/net/ieee802154/6lowpan/6lowpan_i.h
+++ b/net/ieee802154/6lowpan/6lowpan_i.h
@@ -19,8 +19,8 @@ typedef unsigned __bitwise__ lowpan_rx_result;
 struct frag_lowpan_compare_key {
        u16 tag;
        u16 d_size;
-       const struct ieee802154_addr src;
-       const struct ieee802154_addr dst;
+       struct ieee802154_addr src;
+       struct ieee802154_addr dst;
 };
 
 /* Equivalent of ipv4 struct ipq

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 65c0b73..510568c 100644 (file)
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -74,14 +74,14 @@ fq_find(struct net *net, const struct lowpan_802154_cb *cb,
 {
        struct netns_ieee802154_lowpan *ieee802154_lowpan =
                net_ieee802154_lowpan(net);
-       struct frag_lowpan_compare_key key = {
-               .tag = cb->d_tag,
-               .d_size = cb->d_size,
-               .src = *src,
-               .dst = *dst,
-       };
+       struct frag_lowpan_compare_key key = {};
        struct inet_frag_queue *q;
 
+       key.tag = cb->d_tag;
+       key.d_size = cb->d_size;
+       key.src = *src;
+       key.dst = *dst;
+
        q = inet_frag_find(&ieee802154_lowpan->frags, &key);
        if (IS_ERR_OR_NULL(q)) {
                inet_frag_maybe_warn_overflow(q, pr_fmt());
@@ -372,7 +372,7 @@ int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type)
        struct lowpan_frag_queue *fq;
        struct net *net = dev_net(skb->dev);
        struct lowpan_802154_cb *cb = lowpan_802154_cb(skb);
-       struct ieee802154_hdr hdr;
+       struct ieee802154_hdr hdr = {};
        int err;
 
        if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)