From: Nazarov Sergey <s-nazarov@yandex.ru>
To: Paul Moore <paul@paul-moore.com>
Cc: "linux-security-module@vger.kernel.org"
<linux-security-module@vger.kernel.org>,
"selinux@vger.kernel.org" <selinux@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>
Subject: Re: Kernel memory corruption in CIPSO labeled TCP packets processing.
Date: Wed, 30 Jan 2019 16:11:42 +0300 [thread overview]
Message-ID: <3191601548853902@myt6-23299ba78d64.qloud-c.yandex.net> (raw)
In-Reply-To: <CAHC9VhRXc=UAfNidPjYsG561_kc_j2CkD6Db=Kb=Gjyhk3ko6Q@mail.gmail.com>
30.01.2019, 01:42, "Paul Moore" <paul@paul-moore.com>:
> There are several cases where the stack ends up calling icmp_send()
> after the skb has been through ip_options_compile(), that should be
> okay.
>
> --
> paul moore
> www.paul-moore.com
In those cases precompiled ip_options struct used, without the need to reuse ip_options_compile.
I think, for error ICMP packet, we can discard all other options except CIPSO. It will be better, than
send packet, contains wrong option's data. Modified patch 2:
---
net/ipv4/cipso_ipv4.c | 24 ++++++++++++++++++++++--
1 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 777fa3b..797826c 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1735,13 +1735,33 @@ int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
*/
void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
{
+ struct ip_options opt;
+ unsigned char *optptr;
+
if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
return;
+ /*
+ * We might be called above the IP layer,
+ * so we can not use icmp_send and IPCB here.
+ *
+ * For the generated ICMP packet, we create a
+ * temporary ip _options structure, contains
+ * the CIPSO option only, since the other options data
+ * could be modified when the original packet receiving.
+ */
+
+ memset(&opt, 0, sizeof(struct ip_options));
+ optptr = cipso_v4_optptr(skb);
+ if (optptr) {
+ opt.optlen = optptr[1];
+ opt.cipso = optptr - skb_network_header(skb);
+ }
+
if (gateway)
- icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
+ __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, &opt);
else
- icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
+ __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, &opt);
}
/**
next prev parent reply other threads:[~2019-01-30 13:18 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-15 17:06 Kernel memory corruption in CIPSO labeled TCP packets processing Nazarov Sergey
2019-01-15 17:55 ` Casey Schaufler
2019-01-15 19:52 ` Paul Moore
2019-01-18 14:53 ` Paul Moore
2019-01-18 16:34 ` Nazarov Sergey
2019-01-18 17:17 ` Paul Moore
2019-01-21 17:11 ` Nazarov Sergey
2019-01-22 16:49 ` Paul Moore
2019-01-22 17:35 ` Nazarov Sergey
2019-01-22 17:48 ` Paul Moore
2019-01-24 14:46 ` Nazarov Sergey
2019-01-25 16:45 ` Paul Moore
2019-01-28 13:10 ` Nazarov Sergey
2019-01-28 22:18 ` Paul Moore
2019-01-29 7:23 ` Nazarov Sergey
2019-01-29 22:42 ` Paul Moore
2019-01-30 13:11 ` Nazarov Sergey [this message]
2019-01-31 2:10 ` Paul Moore
2019-01-31 13:20 ` Nazarov Sergey
2019-02-11 20:37 ` Paul Moore
2019-02-11 21:21 ` Nazarov Sergey
2019-02-11 23:43 ` Paul Moore
2019-02-12 15:10 ` [PATCH] NETWORKING: avoid use IPCB in cipso_v4_error Nazarov Sergey
2019-02-13 21:41 ` Paul Moore
2019-02-14 18:00 ` Nazarov Sergey
2019-02-14 18:59 ` Stephen Smalley
2019-02-14 16:43 ` David Miller
2019-02-14 18:14 ` Nazarov Sergey
2019-02-15 19:02 ` Paul Moore
2019-02-15 20:00 ` David Miller
2019-02-15 20:04 ` Paul Moore
2019-02-18 13:39 ` Nazarov Sergey
2019-02-19 1:25 ` David Miller
2019-02-22 16:35 ` Nazarov Sergey
2019-02-22 17:39 ` [PATCH v2 0/2] " Nazarov Sergey
2019-02-25 1:33 ` David Miller
2019-02-25 16:24 ` [PATCH v2 1/2] " Nazarov Sergey
2019-02-25 22:07 ` Paul Moore
2019-02-25 22:33 ` David Miller
2019-02-25 23:30 ` Paul Moore
2019-02-25 16:27 ` [PATCH v2 2/2] " Nazarov Sergey
2019-02-25 22:06 ` Paul Moore
2019-02-25 22:34 ` David Miller
2019-02-22 17:43 ` [PATCH v2 1/2] " Nazarov Sergey
2019-02-22 17:50 ` [PATCH v2 2/2] " Nazarov Sergey
2019-02-25 1:33 ` [PATCH] " David Miller
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