From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 8/9] netfilter: nf_tables: fix flowtable list del corruption
Date: Thu, 16 Jan 2020 20:50:43 +0100 [thread overview]
Message-ID: <20200116195044.326614-9-pablo@netfilter.org> (raw)
In-Reply-To: <20200116195044.326614-1-pablo@netfilter.org>
From: Florian Westphal <fw@strlen.de>
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>
---
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 896a6e8aff91..65f51a2e9c2a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1048,12 +1048,18 @@ 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;
--
2.11.0
next prev parent reply other threads:[~2020-01-16 19:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-16 19:50 [PATCH 0/9] Netfilter updates for net Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 1/9] netfilter: fix a use-after-free in mtype_destroy() Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 2/9] netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 3/9] netfilter: nf_tables: store transaction list locally while requesting module Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 4/9] netfilter: nft_tunnel: fix null-attribute check Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 5/9] netfilter: nft_tunnel: ERSPAN_VERSION must not be null Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 6/9] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits Pablo Neira Ayuso
2020-01-16 19:50 ` [PATCH 7/9] netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks() Pablo Neira Ayuso
2020-01-16 19:50 ` Pablo Neira Ayuso [this message]
2020-01-16 19:50 ` [PATCH 9/9] netfilter: nat: fix ICMP header corruption on ICMP errors Pablo Neira Ayuso
2020-01-17 9:37 ` [PATCH 0/9] Netfilter updates for net David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200116195044.326614-9-pablo@netfilter.org \
--to=pablo@netfilter.org \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).