From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Florian Westphal <fw@strlen.de>,
syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com,
Pablo Neira Ayuso <pablo@netfilter.org>,
Sasha Levin <sashal@kernel.org>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 094/107] netfilter: nf_tables: fix flowtable list del corruption
Date: Fri, 24 Jan 2020 09:18:04 -0500 [thread overview]
Message-ID: <20200124141817.28793-94-sashal@kernel.org> (raw)
In-Reply-To: <20200124141817.28793-1-sashal@kernel.org>
From: Florian Westphal <fw@strlen.de>
[ Upstream commit 335178d5429c4cee61b58f4ac80688f556630818 ]
syzbot reported following crash:
list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122)
[..]
Call Trace:
__list_del_entry include/linux/list.h:131 [inline]
list_del_rcu include/linux/rculist.h:148 [inline]
nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183
[..]
The commit transaction list has:
NFT_MSG_NEWTABLE
NFT_MSG_NEWFLOWTABLE
NFT_MSG_DELFLOWTABLE
NFT_MSG_DELTABLE
A missing generation check during DELTABLE processing causes it to queue
the DELFLOWTABLE operation a second time, so we corrupt the list here:
case NFT_MSG_DELFLOWTABLE:
list_del_rcu(&nft_trans_flowtable(trans)->list);
nf_tables_flowtable_notify(&trans->ctx,
because we have two different DELFLOWTABLE transactions for the same
flowtable. We then call list_del_rcu() twice for the same flowtable->list.
The object handling seems to suffer from the same bug so add a generation
check too and only queue delete transactions for flowtables/objects that
are still active in the next generation.
Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com
Fixes: 3b49e2e94e6eb ("netfilter: nf_tables: add flow table netlink frontend")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 6fa315b73a66a..9fefd01500918 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -981,12 +981,18 @@ static int nft_flush_table(struct nft_ctx *ctx)
}
list_for_each_entry_safe(flowtable, nft, &ctx->table->flowtables, list) {
+ if (!nft_is_active_next(ctx->net, flowtable))
+ continue;
+
err = nft_delflowtable(ctx, flowtable);
if (err < 0)
goto out;
}
list_for_each_entry_safe(obj, ne, &ctx->table->objects, list) {
+ if (!nft_is_active_next(ctx->net, obj))
+ continue;
+
err = nft_delobj(ctx, obj);
if (err < 0)
goto out;
--
2.20.1
next prev parent reply other threads:[~2020-01-24 14:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200124141817.28793-1-sashal@kernel.org>
2020-01-24 14:17 ` [PATCH AUTOSEL 5.4 059/107] netfilter: fix a use-after-free in mtype_destroy() Sasha Levin
2020-01-24 14:17 ` [PATCH AUTOSEL 5.4 060/107] netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct Sasha Levin
2020-01-24 14:18 ` [PATCH AUTOSEL 5.4 090/107] netfilter: nf_tables: store transaction list locally while requesting module Sasha Levin
2020-01-24 14:18 ` [PATCH AUTOSEL 5.4 091/107] netfilter: nft_tunnel: fix null-attribute check Sasha Levin
2020-01-24 14:18 ` [PATCH AUTOSEL 5.4 092/107] netfilter: nft_tunnel: ERSPAN_VERSION must not be null Sasha Levin
2020-01-24 14:18 ` [PATCH AUTOSEL 5.4 093/107] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits Sasha Levin
2020-01-24 14:18 ` Sasha Levin [this message]
2020-01-24 14:18 ` [PATCH AUTOSEL 5.4 095/107] netfilter: nat: fix ICMP header corruption on ICMP errors Sasha Levin
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