From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 4/4] netfilter: synproxy: Check oom when adding synproxy and seqadj ct extensions
Date: Tue, 13 Sep 2016 11:05:17 +0200 [thread overview]
Message-ID: <1473757517-3764-5-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1473757517-3764-1-git-send-email-pablo@netfilter.org>
From: Gao Feng <fgao@ikuai8.com>
When memory is exhausted, nfct_seqadj_ext_add may fail to add the
synproxy and seqadj extensions. The function nf_ct_seqadj_init doesn't
check if get valid seqadj pointer by the nfct_seqadj.
Now drop the packet directly when fail to add seqadj extension to
avoid dereference NULL pointer in nf_ct_seqadj_init from
init_conntrack().
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_conntrack_synproxy.h | 14 ++++++++++++++
net/netfilter/nf_conntrack_core.c | 6 +++---
net/netfilter/nf_nat_core.c | 3 ++-
3 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_synproxy.h b/include/net/netfilter/nf_conntrack_synproxy.h
index 6793614..e693731 100644
--- a/include/net/netfilter/nf_conntrack_synproxy.h
+++ b/include/net/netfilter/nf_conntrack_synproxy.h
@@ -27,6 +27,20 @@ static inline struct nf_conn_synproxy *nfct_synproxy_ext_add(struct nf_conn *ct)
#endif
}
+static inline bool nf_ct_add_synproxy(struct nf_conn *ct,
+ const struct nf_conn *tmpl)
+{
+ if (tmpl && nfct_synproxy(tmpl)) {
+ if (!nfct_seqadj_ext_add(ct))
+ return false;
+
+ if (!nfct_synproxy_ext_add(ct))
+ return false;
+ }
+
+ return true;
+}
+
struct synproxy_stats {
unsigned int syn_received;
unsigned int cookie_invalid;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index dd2c43a..9934b0c 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1035,9 +1035,9 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
if (IS_ERR(ct))
return (struct nf_conntrack_tuple_hash *)ct;
- if (tmpl && nfct_synproxy(tmpl)) {
- nfct_seqadj_ext_add(ct);
- nfct_synproxy_ext_add(ct);
+ if (!nf_ct_add_synproxy(ct, tmpl)) {
+ nf_conntrack_free(ct);
+ return ERR_PTR(-ENOMEM);
}
timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 19c081e..ecee105 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -441,7 +441,8 @@ nf_nat_setup_info(struct nf_conn *ct,
ct->status |= IPS_DST_NAT;
if (nfct_help(ct))
- nfct_seqadj_ext_add(ct);
+ if (!nfct_seqadj_ext_add(ct))
+ return NF_DROP;
}
if (maniptype == NF_NAT_MANIP_SRC) {
--
2.1.4
next prev parent reply other threads:[~2016-09-13 9:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 9:05 [PATCH 0/4] Netfilter fixes for net Pablo Neira Ayuso
2016-09-13 9:05 ` [PATCH 1/4] netfilter: nf_tables_trace: fix endiness when dump chain policy Pablo Neira Ayuso
2016-09-13 9:05 ` [PATCH 2/4] netfilter: nft_chain_route: re-route before skb is queued to userspace Pablo Neira Ayuso
2016-09-13 9:05 ` [PATCH 3/4] netfilter: nf_nat: handle NF_DROP from nfnetlink_parse_nat_setup() Pablo Neira Ayuso
2016-09-13 9:05 ` Pablo Neira Ayuso [this message]
2016-09-13 15:17 ` [PATCH 0/4] Netfilter fixes 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=1473757517-3764-5-git-send-email-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).