From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
syzbot+355cab184197dbbfa384@syzkaller.appspotmail.com,
Sven Eckelmann <sven@narfation.org>,
Antonio Quartulli <a@unstable.cc>,
Simon Wunderlich <sw@simonwunderlich.de>
Subject: [PATCH 4.9 10/14] batman-adv: Only read OGM tvlv_len after buffer len check
Date: Fri, 13 Sep 2019 14:07:03 +0100 [thread overview]
Message-ID: <20190913130445.741374686@linuxfoundation.org> (raw)
In-Reply-To: <20190913130440.264749443@linuxfoundation.org>
From: Sven Eckelmann <sven@narfation.org>
commit a15d56a60760aa9dbe26343b9a0ac5228f35d445 upstream.
Multiple batadv_ogm_packet can be stored in an skbuff. The functions
batadv_iv_ogm_send_to_if()/batadv_iv_ogm_receive() use
batadv_iv_ogm_aggr_packet() to check if there is another additional
batadv_ogm_packet in the skb or not before they continue processing the
packet.
The length for such an OGM is BATADV_OGM_HLEN +
batadv_ogm_packet->tvlv_len. The check must first check that at least
BATADV_OGM_HLEN bytes are available before it accesses tvlv_len (which is
part of the header. Otherwise it might try read outside of the currently
available skbuff to get the content of tvlv_len.
Fixes: ef26157747d4 ("batman-adv: tvlv - basic infrastructure")
Reported-by: syzbot+355cab184197dbbfa384@syzkaller.appspotmail.com
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/batman-adv/bat_iv_ogm.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -450,17 +450,23 @@ static u8 batadv_hop_penalty(u8 tq, cons
* batadv_iv_ogm_aggr_packet - checks if there is another OGM attached
* @buff_pos: current position in the skb
* @packet_len: total length of the skb
- * @tvlv_len: tvlv length of the previously considered OGM
+ * @ogm_packet: potential OGM in buffer
*
* Return: true if there is enough space for another OGM, false otherwise.
*/
-static bool batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
- __be16 tvlv_len)
+static bool
+batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
+ const struct batadv_ogm_packet *ogm_packet)
{
int next_buff_pos = 0;
- next_buff_pos += buff_pos + BATADV_OGM_HLEN;
- next_buff_pos += ntohs(tvlv_len);
+ /* check if there is enough space for the header */
+ next_buff_pos += buff_pos + sizeof(*ogm_packet);
+ if (next_buff_pos > packet_len)
+ return false;
+
+ /* check if there is enough space for the optional TVLV */
+ next_buff_pos += ntohs(ogm_packet->tvlv_len);
return (next_buff_pos <= packet_len) &&
(next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
@@ -488,7 +494,7 @@ static void batadv_iv_ogm_send_to_if(str
/* adjust all flags and log packets */
while (batadv_iv_ogm_aggr_packet(buff_pos, forw_packet->packet_len,
- batadv_ogm_packet->tvlv_len)) {
+ batadv_ogm_packet)) {
/* we might have aggregated direct link packets with an
* ordinary base packet
*/
@@ -1841,7 +1847,7 @@ static int batadv_iv_ogm_receive(struct
/* unpack the aggregated packets and process them one by one */
while (batadv_iv_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
- ogm_packet->tvlv_len)) {
+ ogm_packet)) {
batadv_iv_ogm_process(skb, ogm_offset, if_incoming);
ogm_offset += BATADV_OGM_HLEN;
next prev parent reply other threads:[~2019-09-13 13:33 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-13 13:06 [PATCH 4.9 00/14] 4.9.193-stable review Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 01/14] ALSA: hda - Fix potential endless loop at applying quirks Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 02/14] ALSA: hda/realtek - Fix overridden device-specific initialization Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 03/14] sched/fair: Dont assign runtime for throttled cfs_rq Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 04/14] drm/vmwgfx: Fix double free in vmw_recv_msg() Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 05/14] powerpc/tm: Fix FP/VMX unavailable exceptions inside a transaction Greg Kroah-Hartman
2019-09-13 13:06 ` [PATCH 4.9 06/14] xfrm: clean up xfrm protocol checks Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 07/14] ip6: fix skb leak in ip6frag_expire_frag_queue() Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 08/14] vhost/test: fix build for vhost test Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 09/14] batman-adv: fix uninit-value in batadv_netlink_get_ifindex() Greg Kroah-Hartman
2019-09-13 13:07 ` Greg Kroah-Hartman [this message]
2019-09-13 13:07 ` [PATCH 4.9 11/14] scripts/decode_stacktrace: match basepath using shell prefix operator, not regex Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 12/14] clk: s2mps11: Add used attribute to s2mps11_dt_match Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 13/14] vhost: block speculation of translated descriptors Greg Kroah-Hartman
2019-09-13 13:07 ` [PATCH 4.9 14/14] vhost: make sure log_num < in_num Greg Kroah-Hartman
2019-09-13 20:19 ` [PATCH 4.9 00/14] 4.9.193-stable review kernelci.org bot
2019-09-14 3:58 ` Naresh Kamboju
2019-09-14 8:28 ` Guenter Roeck
2019-09-14 8:31 ` Greg Kroah-Hartman
2019-09-14 8:39 ` Guenter Roeck
2019-09-15 0:49 ` Guenter Roeck
2019-09-15 12:58 ` Greg Kroah-Hartman
2019-09-15 16:09 ` Guenter Roeck
2019-09-16 6:07 ` Greg Kroah-Hartman
2019-09-14 14:16 ` Guenter Roeck
2019-09-15 13:35 ` Greg Kroah-Hartman
2019-09-16 10:44 ` Naresh Kamboju
2019-09-16 10:45 ` Greg Kroah-Hartman
2019-09-16 9:17 ` Jon Hunter
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