From: Steffen Klassert <steffen.klassert@secunet•com>
To: David Miller <davem@davemloft•net>
Cc: Herbert Xu <herbert@gondor•apana.org.au>,
Steffen Klassert <steffen.klassert@secunet•com>,
<netdev@vger•kernel.org>
Subject: [PATCH 02/11] xfrm: skip policies marked as dead while rehashing
Date: Thu, 11 Jan 2018 12:37:37 +0100 [thread overview]
Message-ID: <20180111113746.28186-3-steffen.klassert@secunet.com> (raw)
In-Reply-To: <20180111113746.28186-1-steffen.klassert@secunet.com>
From: Florian Westphal <fw@strlen•de>
syzkaller triggered following KASAN splat:
BUG: KASAN: slab-out-of-bounds in xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
read of size 2 at addr ffff8801c8e92fe4 by task kworker/1:1/23 [..]
Workqueue: events xfrm_hash_rebuild [..]
__asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
process_one_work+0xbbf/0x1b10 kernel/workqueue.c:2112
worker_thread+0x223/0x1990 kernel/workqueue.c:2246 [..]
The reproducer triggers:
1016 if (error) {
1017 list_move_tail(&walk->walk.all, &x->all);
1018 goto out;
1019 }
in xfrm_policy_walk() via pfkey (it sets tiny rcv space, dump
callback returns -ENOBUFS).
In this case, *walk is located the pfkey socket struct, so this socket
becomes visible in the global policy list.
It looks like this is intentional -- phony walker has walk.dead set to 1
and all other places skip such "policies".
Ccing original authors of the two commits that seem to expose this
issue (first patch missed ->dead check, second patch adds pfkey
sockets to policies dumper list).
Fixes: 880a6fab8f6ba5b ("xfrm: configure policy hash table thresholds by netlink")
Fixes: 12a169e7d8f4b1c ("ipsec: Put dumpers on the dump list")
Cc: Herbert Xu <herbert@gondor•apana.org.au>
Cc: Timo Teras <timo.teras@iki•fi>
Cc: Christophe Gouault <christophe.gouault@6wind•com>
Reported-by: syzbot <bot+c028095236fcb6f4348811565b75084c754dc729@syzkaller•appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen•de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet•com>
---
net/xfrm/xfrm_policy.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 70aa5cb0c659..2ef6db98e9ba 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -609,7 +609,8 @@ static void xfrm_hash_rebuild(struct work_struct *work)
/* re-insert all policies by order of creation */
list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
- if (xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
+ if (policy->walk.dead ||
+ xfrm_policy_id2dir(policy->index) >= XFRM_POLICY_MAX) {
/* skip socket policies */
continue;
}
--
2.14.1
next prev parent reply other threads:[~2018-01-11 11:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-11 11:37 pull request (net): ipsec 2018-01-11 Steffen Klassert
2018-01-11 11:37 ` [PATCH 01/11] xfrm: Forbid state updates from changing encap type Steffen Klassert
2018-01-11 11:37 ` Steffen Klassert [this message]
2018-01-11 11:37 ` [PATCH 03/11] af_key: fix buffer overread in verify_address_len() Steffen Klassert
2018-01-11 11:37 ` [PATCH 04/11] af_key: fix buffer overread in parse_exthdrs() Steffen Klassert
2018-01-11 11:37 ` [PATCH 05/11] xfrm: fix rcu usage in xfrm_get_type_offload Steffen Klassert
2018-01-11 11:37 ` [PATCH 06/11] xfrm: Use __skb_queue_tail in xfrm_trans_queue Steffen Klassert
2018-01-11 11:37 ` [PATCH 07/11] xfrm: Return error on unknown encap_type in init_state Steffen Klassert
2018-01-11 11:37 ` [PATCH 08/11] xfrm: don't call xfrm_policy_cache_flush while holding spinlock Steffen Klassert
2018-01-11 11:37 ` [PATCH 09/11] esp: Fix GRO when the headers not fully in the linear part of the skb Steffen Klassert
2018-01-11 11:37 ` [PATCH 10/11] af_key: Fix memory leak in key_notify_policy Steffen Klassert
2018-01-11 11:37 ` [PATCH 11/11] xfrm: Fix a race in the xdst pcpu cache Steffen Klassert
2018-01-12 15:33 ` pull request (net): ipsec 2018-01-11 David Miller
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