netdev - [PATCH] 6lowpan: Uncompression of traffic class field was incorrect

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1384333419-4087-1-git-send-email-jukka.rissanen@linux.intel.com>
Date:	Wed, 13 Nov 2013 11:03:39 +0200
From:	Jukka Rissanen <jukka.rissanen@...ux.intel.com>
To:	netdev@...r.kernel.org
Cc:	alex.aring@...il.com
Subject: [PATCH] 6lowpan: Uncompression of traffic class field was incorrect

If priority/traffic class field in IPv6 header is set (seen when
using ssh), the uncompression sets the TC and Flow fields incorrectly.

Example:

This is IPv6 header of a sent packet. Note the priority/TC (=1) in
the first byte.

00000000: 61 00 00 00 00 2c 06 40 fe 80 00 00 00 00 00 00
00000010: 02 02 72 ff fe c6 42 10 fe 80 00 00 00 00 00 00
00000020: 02 1e ab ff fe 4c 52 57

This gets compressed like this in the sending side

00000000: 72 31 04 06 02 1e ab ff fe 4c 52 57 ec c2 00 16
00000010: aa 2d fe 92 86 4e be c6 ....

In the receiving end, the packet gets uncompressed to this
IPv6 header

00000000: 60 06 06 02 00 2a 1e 40 fe 80 00 00 00 00 00 00
00000010: 02 02 72 ff fe c6 42 10 fe 80 00 00 00 00 00 00
00000020: ab ff fe 4c 52 57 ec c2

First four bytes are set incorrectly and we have also lost
two bytes from destination address.

The fix is to switch the case values in switch statement
when checking the TC field.

Signed-off-by: Jukka Rissanen <jukka.rissanen@...ux.intel.com>
---
 net/ieee802154/6lowpan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 426b5df..459e200 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -956,7 +956,7 @@ lowpan_process_data(struct sk_buff *skb)
 	 * Traffic class carried in-line
 	 * ECN + DSCP (1 byte), Flow Label is elided
 	 */
-	case 1: /* 10b */
+	case 2: /* 10b */
 		if (lowpan_fetch_skb_u8(skb, &tmp))
 			goto drop;
 
@@ -967,7 +967,7 @@ lowpan_process_data(struct sk_buff *skb)
 	 * Flow Label carried in-line
 	 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
 	 */
-	case 2: /* 01b */
+	case 1: /* 01b */
 		if (lowpan_fetch_skb_u8(skb, &tmp))
 			goto drop;
 
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html