diff options
| author | Al Viro | 2018-10-08 06:22:34 -0400 |
|---|---|---|
| committer | David S. Miller | 2018-10-08 10:33:34 -0700 |
| commit | 27594ec4b6a7035450ba43624d1648cbd2c0aaea (patch) | |
| tree | da8a30c41f7825aa2defb535390bd33911ad5de7 | |
| parent | b44ef84542dd79aeacd09d43e073e25a1bb1f407 (diff) | |
net: sched: cls_u32: disallow linking to root hnode
Operation makes no sense. Nothing will actually break if we do so
(depth limit in u32_classify() will prevent infinite loops), but
according to maintainers it's best prohibited outright.
NOTE: doing so guarantees that u32_destroy() will trigger the call
of u32_destroy_hnode(); we might want to make that unconditional.
Test:
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol ip prio 100 u32 \
link 800: offset at 0 mask 0f00 shift 6 plus 0 eat match ip protocol 6 ff
should fail with
Error: cls_u32: Not linking to root node
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sched/cls_u32.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 622f4657da94..3357331a80a2 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -797,6 +797,10 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp, NL_SET_ERR_MSG_MOD(extack, "Link hash table not found"); return -EINVAL; } + if (ht_down->is_root) { + NL_SET_ERR_MSG_MOD(extack, "Not linking to root node"); + return -EINVAL; + } ht_down->refcnt++; } |