netfilter: expect: fix crash when putting uninited expectation

We crash in __nf_ct_expect_check, it calls nf_ct_remove_expect on the
uninitialised expectation instead of existing one, so del_timer chokes
on random memory address.

Fixes: ec0e3f01114ad32711243 ("netfilter: nf_ct_expect: Add nf_ct_remove_expect()")
Reported-by: Sergey Kvachonok <ravenexp@gmail.com>
Tested-by: Sergey Kvachonok <ravenexp@gmail.com>
Cc: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index e03d16ed550d6bf07a537f4b150148a3cd967f59..899c2c36da136fe3e7268e44437a8d49d73789e2 100644 (file)
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -422,7 +422,7 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect)
        h = nf_ct_expect_dst_hash(net, &expect->tuple);
        hlist_for_each_entry_safe(i, next, &nf_ct_expect_hash[h], hnode) {
                if (expect_matches(i, expect)) {
-                       if (nf_ct_remove_expect(expect))
+                       if (nf_ct_remove_expect(i))
                                break;
                } else if (expect_clash(i, expect)) {
                        ret = -EBUSY;