From: Ido Schimmel <idosch@xxxxxxxxxx>
[ Upstream commit d3f87278bcb80bd7f9519669d928b43320363d4f ]
The kernel does not currently validate that both the minimum and maximum
ports of a port range are specified. This can lead user space to think
that a filter matching on a port range was successfully added, when in
fact it was not. For example, with a patched (buggy) iproute2 that only
sends the minimum port, the following commands do not return an error:
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp src_port 100-200 action pass
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp dst_port 100-200 action pass
# tc filter show dev swp1 ingress
filter protocol ip pref 1 flower chain 0
filter protocol ip pref 1 flower chain 0 handle 0x1
eth_type ipv4
ip_proto udp
not_in_hw
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
filter protocol ip pref 1 flower chain 0 handle 0x2
eth_type ipv4
ip_proto udp
not_in_hw
action order 1: gact action pass
random type none pass val 0
index 2 ref 1 bind 1
Fix by returning an error unless both ports are specified:
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp src_port 100-200 action pass
Error: Both min and max source ports must be specified.
We have an error talking to the kernel
# tc filter add dev swp1 ingress pref 1 proto ip flower ip_proto udp dst_port 100-200 action pass
Error: Both min and max destination ports must be specified.
We have an error talking to the kernel
Fixes: 5c72299fba9d ("net: sched: cls_flower: Classify packets using port ranges")
Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxx>
Reviewed-by: Petr Machata <petrm@xxxxxxxxxx>
Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sched/cls_flower.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index caf1a05bfbde4..dcf21d99f132c 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -778,6 +778,16 @@ static int fl_set_key_port_range(struct nlattr **tb, struct fl_flow_key *key,
TCA_FLOWER_KEY_PORT_SRC_MAX, &mask->tp_range.tp_max.src,
TCA_FLOWER_UNSPEC, sizeof(key->tp_range.tp_max.src));
+ if (mask->tp_range.tp_min.dst != mask->tp_range.tp_max.dst) {
+ NL_SET_ERR_MSG(extack,
+ "Both min and max destination ports must be specified");
+ return -EINVAL;
+ }
+ if (mask->tp_range.tp_min.src != mask->tp_range.tp_max.src) {
+ NL_SET_ERR_MSG(extack,
+ "Both min and max source ports must be specified");
+ return -EINVAL;
+ }
if (mask->tp_range.tp_min.dst && mask->tp_range.tp_max.dst &&
ntohs(key->tp_range.tp_max.dst) <=
ntohs(key->tp_range.tp_min.dst)) {
--
2.39.2
