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authorFlorian Westphal <fw@strlen.de>2015-12-08 23:35:19 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2015-12-09 14:26:31 +0100
commite97ac12859dbf4d3ee0eddb9798867541d1d1e1e (patch)
treeedb988527d916389a065d447fbc830870ab82933 /net/ipv6
parente639f7ab079b5256660018511d87aa34b54f1a9d (diff)
downloadop-kernel-dev-e97ac12859dbf4d3ee0eddb9798867541d1d1e1e.zip
op-kernel-dev-e97ac12859dbf4d3ee0eddb9798867541d1d1e1e.tar.gz
netfilter: ipv6: nf_defrag: fix NULL deref panic
Valdis reports NULL deref in nf_ct_frag6_gather. Problem is bogus use of skb_queue_walk() -- we miss first skb in the list since we start with head->next instead of head. In case the element we're looking for was head->next we won't find a result and then trip over NULL iter. (defrag uses plain NULL-terminated list rather than one terminated by head-of-list-pointer, which is what skb_queue_walk expects). Fixes: 029f7f3b8701cc7a ("netfilter: ipv6: nf_defrag: avoid/free clone operations") Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/netfilter/nf_conntrack_reasm.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 912bc3a..6e5f0e0d 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -441,11 +441,14 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_devic
return false;
fp->next = prev->next;
- skb_queue_walk(head, iter) {
- if (iter->next != prev)
- continue;
- iter->next = fp;
- break;
+
+ iter = head;
+ while (iter) {
+ if (iter->next == prev) {
+ iter->next = fp;
+ break;
+ }
+ iter = iter->next;
}
skb_morph(prev, head);
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