netdev - [PATCH 5/5] netfilter: expect: fix crash when putting uninited expectation

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Message-Id: <1500372839-6735-6-git-send-email-pablo@netfilter.org>
Date:   Tue, 18 Jul 2017 12:13:59 +0200
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 5/5] netfilter: expect: fix crash when putting uninited expectation

From: Florian Westphal <fw@...len.de>

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@...il.com>
Tested-by: Sergey Kvachonok <ravenexp@...il.com>
Cc: Gao Feng <fgao@...ai8.com>
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nf_conntrack_expect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index e03d16ed550d..899c2c36da13 100644
--- 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;
-- 
2.1.4