From: Eric Dumazet <eric.dumazet@gmail.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netdev <netdev@vger.kernel.org>,
netfilter-devel@vger.kernel.org, Florian Westphal <fw@strlen.de>
Subject: [PATCH net] netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_match()
Date: Wed, 24 Jan 2018 14:49:48 -0800 [thread overview]
Message-ID: <1516834188.3715.35.camel@gmail.com> (raw)
From: Eric Dumazet <edumazet@google.com>
It looks like syzbot found its way into netfilter territory.
Issue here is that @name comes from user space and might
not be null terminated.
Out-of-bound reads happen, KASAN is not happy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
No Fixes: tag, bug seems to be a day-0 one.
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 55802e97f906d1987ed78b4296584deb38e5f876..8516dc459b539342f44d2b2b3e21b140677c7826 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -210,6 +210,9 @@ xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
{
struct xt_match *match;
+ if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
+ return ERR_PTR(-EINVAL);
+
match = xt_find_match(nfproto, name, revision);
if (IS_ERR(match)) {
request_module("%st_%s", xt_prefix[nfproto], name);
next reply other threads:[~2018-01-24 22:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-24 22:49 Eric Dumazet [this message]
2018-01-24 23:19 ` [PATCH net] netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_match() Florian Westphal
2018-01-24 23:50 ` Pablo Neira Ayuso
2018-01-25 0:13 ` Pablo Neira Ayuso
2018-01-25 1:13 ` Eric Dumazet
2018-01-25 1:16 ` [PATCH v2 net] netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_{match|target} Eric Dumazet
2018-01-25 6:09 ` Florian Westphal
2018-01-25 11:33 ` Pablo Neira Ayuso
2018-01-24 23:49 ` [PATCH net] netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_match() Pablo Neira Ayuso
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