Hi David,
here is another small batman-adv pull request for net.
Please pull or let me know of any problem!
Thank you, Simon
The following changes since commit 3ee1bb7aae97324ec9078da1f00cb2176919563f:
batman-adv: fix uninit-value in batadv_netlink_get_ifindex() (2019-08-14 19:27:07 +0200)
are available in the Git repository at:
git://git.open-mesh.org/linux-merge.git tags/batadv-net-for-davem-20190830
for you to fetch changes up to 0ff0f15a32c093381ad1abc06abe85afb561ab28:
batman-adv: Only read OGM2 tvlv_len after buffer len check (2019-08-23 18:20:31 +0200)
---------------------------------------------------------------- Here are two batman-adv bugfixes:
- Fix OGM and OGMv2 header read boundary check, by Sven Eckelmann (2 patches)
---------------------------------------------------------------- Sven Eckelmann (2): batman-adv: Only read OGM tvlv_len after buffer len check batman-adv: Only read OGM2 tvlv_len after buffer len check
net/batman-adv/bat_iv_ogm.c | 20 +++++++++++++------- net/batman-adv/bat_v_ogm.c | 18 ++++++++++++------ 2 files changed, 25 insertions(+), 13 deletions(-)
From: Sven Eckelmann sven@narfation.org
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 --- net/batman-adv/bat_iv_ogm.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 240ed70912d6..d78938e3e008 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -277,17 +277,23 @@ static u8 batadv_hop_penalty(u8 tq, const struct batadv_priv *bat_priv) * 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); @@ -315,7 +321,7 @@ static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
/* 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 */ @@ -1704,7 +1710,7 @@ static int batadv_iv_ogm_receive(struct sk_buff *skb,
/* 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;
From: Sven Eckelmann sven@narfation.org
Multiple batadv_ogm2_packet can be stored in an skbuff. The functions batadv_v_ogm_send_to_if() uses batadv_v_ogm_aggr_packet() to check if there is another additional batadv_ogm2_packet in the skb or not before they continue processing the packet.
The length for such an OGM2 is BATADV_OGM2_HLEN + batadv_ogm2_packet->tvlv_len. The check must first check that at least BATADV_OGM2_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: 9323158ef9f4 ("batman-adv: OGMv2 - implement originators logic") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/bat_v_ogm.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index fad95ef64e01..bc06e3cdfa84 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -631,17 +631,23 @@ batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated * @buff_pos: current position in the skb * @packet_len: total length of the skb - * @tvlv_len: tvlv length of the previously considered OGM + * @ogm2_packet: potential OGM2 in buffer * * Return: true if there is enough space for another OGM, false otherwise. */ -static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, - __be16 tvlv_len) +static bool +batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, + const struct batadv_ogm2_packet *ogm2_packet) { int next_buff_pos = 0;
- next_buff_pos += buff_pos + BATADV_OGM2_HLEN; - next_buff_pos += ntohs(tvlv_len); + /* check if there is enough space for the header */ + next_buff_pos += buff_pos + sizeof(*ogm2_packet); + if (next_buff_pos > packet_len) + return false; + + /* check if there is enough space for the optional TVLV */ + next_buff_pos += ntohs(ogm2_packet->tvlv_len);
return (next_buff_pos <= packet_len) && (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); @@ -818,7 +824,7 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, ogm_packet = (struct batadv_ogm2_packet *)skb->data;
while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), - ogm_packet->tvlv_len)) { + ogm_packet)) { batadv_v_ogm_process(skb, ogm_offset, if_incoming);
ogm_offset += BATADV_OGM2_HLEN;
From: Simon Wunderlich sw@simonwunderlich.de Date: Fri, 30 Aug 2019 09:25:00 +0200
here is another small batman-adv pull request for net.
Please pull or let me know of any problem!
Pulled, thanks Simon.
b.a.t.m.a.n@lists.open-mesh.org
-
David Miller -
Simon Wunderlich