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| author | Florian Westphal <fw@strlen.de> | 2015-12-08 23:35:19 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-12-09 14:26:31 +0100 |
| commit | e97ac12859dbf4d3ee0eddb9798867541d1d1e1e (patch) | |
| tree | edb988527d916389a065d447fbc830870ab82933 | |
| parent | e639f7ab079b5256660018511d87aa34b54f1a9d (diff) | |
| download | linux-e97ac12859dbf4d3ee0eddb9798867541d1d1e1e.tar.gz linux-e97ac12859dbf4d3ee0eddb9798867541d1d1e1e.tar.bz2 linux-e97ac12859dbf4d3ee0eddb9798867541d1d1e1e.zip | |
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>
| -rw-r--r-- | net/ipv6/netfilter/nf_conntrack_reasm.c | 13 |
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 912bc3afc183..6e5f0e0d49e0 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); |