* [PATCH net 1/3] amt: fix wrong usage of pskb_may_pull()
2022-06-02 14:01 [PATCH net 0/3] amt: fix several bugs in amt_rcv() Taehee Yoo
@ 2022-06-02 14:01 ` Taehee Yoo
2022-06-02 14:01 ` [PATCH net 2/3] amt: fix possible null-ptr-deref in amt_rcv() Taehee Yoo
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Taehee Yoo @ 2022-06-02 14:01 UTC (permalink / raw)
To: davem, kuba, pabeni, edumazet, netdev; +Cc: ap420073
It adds missing pskb_may_pull() in amt_update_handler() and
amt_multicast_data_handler().
And it fixes wrong parameter of pskb_may_pull() in
amt_advertisement_handler() and amt_membership_query_handler().
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
drivers/net/amt.c | 55 +++++++++++++++++++++++++++++++----------------
1 file changed, 37 insertions(+), 18 deletions(-)
diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index ebee5f07a208..900948e135ad 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -2220,8 +2220,7 @@ static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
struct amt_header_advertisement *amta;
int hdr_size;
- hdr_size = sizeof(*amta) - sizeof(struct amt_header);
-
+ hdr_size = sizeof(*amta) + sizeof(struct udphdr);
if (!pskb_may_pull(skb, hdr_size))
return true;
@@ -2251,19 +2250,27 @@ static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
struct ethhdr *eth;
struct iphdr *iph;
+ hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
+ if (!pskb_may_pull(skb, hdr_size))
+ return true;
+
amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
if (amtmd->reserved || amtmd->version)
return true;
- hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
return true;
+
skb_reset_network_header(skb);
skb_push(skb, sizeof(*eth));
skb_reset_mac_header(skb);
skb_pull(skb, sizeof(*eth));
eth = eth_hdr(skb);
+
+ if (!pskb_may_pull(skb, sizeof(*iph)))
+ return true;
iph = ip_hdr(skb);
+
if (iph->version == 4) {
if (!ipv4_is_multicast(iph->daddr))
return true;
@@ -2274,6 +2281,9 @@ static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
} else if (iph->version == 6) {
struct ipv6hdr *ip6h;
+ if (!pskb_may_pull(skb, sizeof(*ip6h)))
+ return true;
+
ip6h = ipv6_hdr(skb);
if (!ipv6_addr_is_multicast(&ip6h->daddr))
return true;
@@ -2306,8 +2316,7 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
struct iphdr *iph;
int hdr_size, len;
- hdr_size = sizeof(*amtmq) - sizeof(struct amt_header);
-
+ hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
if (!pskb_may_pull(skb, hdr_size))
return true;
@@ -2315,22 +2324,27 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
if (amtmq->reserved || amtmq->version)
return true;
- hdr_size = sizeof(*amtmq) + sizeof(struct udphdr) - sizeof(*eth);
+ hdr_size -= sizeof(*eth);
if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
return true;
+
oeth = eth_hdr(skb);
skb_reset_mac_header(skb);
skb_pull(skb, sizeof(*eth));
skb_reset_network_header(skb);
eth = eth_hdr(skb);
+ if (!pskb_may_pull(skb, sizeof(*iph)))
+ return true;
+
iph = ip_hdr(skb);
if (iph->version == 4) {
- if (!ipv4_is_multicast(iph->daddr))
- return true;
if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
sizeof(*ihv3)))
return true;
+ if (!ipv4_is_multicast(iph->daddr))
+ return true;
+
ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
skb_reset_transport_header(skb);
skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
@@ -2345,15 +2359,17 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
ip_eth_mc_map(iph->daddr, eth->h_dest);
#if IS_ENABLED(CONFIG_IPV6)
} else if (iph->version == 6) {
- struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct mld2_query *mld2q;
+ struct ipv6hdr *ip6h;
- if (!ipv6_addr_is_multicast(&ip6h->daddr))
- return true;
if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
sizeof(*mld2q)))
return true;
+ ip6h = ipv6_hdr(skb);
+ if (!ipv6_addr_is_multicast(&ip6h->daddr))
+ return true;
+
mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
skb_reset_transport_header(skb);
skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
@@ -2389,23 +2405,23 @@ static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
{
struct amt_header_membership_update *amtmu;
struct amt_tunnel_list *tunnel;
- struct udphdr *udph;
struct ethhdr *eth;
struct iphdr *iph;
- int len;
+ int len, hdr_size;
iph = ip_hdr(skb);
- udph = udp_hdr(skb);
- if (__iptunnel_pull_header(skb, sizeof(*udph), skb->protocol,
- false, false))
+ hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
+ if (!pskb_may_pull(skb, hdr_size))
return true;
- amtmu = (struct amt_header_membership_update *)skb->data;
+ amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
if (amtmu->reserved || amtmu->version)
return true;
- skb_pull(skb, sizeof(*amtmu));
+ if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
+ return true;
+
skb_reset_network_header(skb);
list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
@@ -2426,6 +2442,9 @@ static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
return true;
report:
+ if (!pskb_may_pull(skb, sizeof(*iph)))
+ return true;
+
iph = ip_hdr(skb);
if (iph->version == 4) {
if (ip_mc_check_igmp(skb)) {
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH net 2/3] amt: fix possible null-ptr-deref in amt_rcv()
2022-06-02 14:01 [PATCH net 0/3] amt: fix several bugs in amt_rcv() Taehee Yoo
2022-06-02 14:01 ` [PATCH net 1/3] amt: fix wrong usage of pskb_may_pull() Taehee Yoo
@ 2022-06-02 14:01 ` Taehee Yoo
2022-06-02 14:01 ` [PATCH net 3/3] amt: fix wrong type string definition Taehee Yoo
2022-06-06 22:04 ` [PATCH net 0/3] amt: fix several bugs in amt_rcv() patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: Taehee Yoo @ 2022-06-02 14:01 UTC (permalink / raw)
To: davem, kuba, pabeni, edumazet, netdev; +Cc: ap420073
When amt interface receives amt message, it tries to obtain amt private
data from sock.
If there is no amt private data, it frees an skb immediately.
After kfree_skb(), it increases the rx_dropped stats.
But in order to use rx_dropped, amt private data is needed.
So, it makes amt_rcv() to do not increase rx_dropped stats when it can
not obtain amt private data.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 1a1a0e80e005 ("amt: fix possible memory leak in amt_rcv()")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
drivers/net/amt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index 900948e135ad..ef483bf51033 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -2698,7 +2698,8 @@ static int amt_rcv(struct sock *sk, struct sk_buff *skb)
amt = rcu_dereference_sk_user_data(sk);
if (!amt) {
err = true;
- goto drop;
+ kfree_skb(skb);
+ goto out;
}
skb->dev = amt->dev;
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread