diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2018-10-08 06:22:33 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-10-08 10:33:34 -0700 |
| commit | b44ef84542dd79aeacd09d43e073e25a1bb1f407 (patch) | |
| tree | 2d4248a5d38f071d82adb8215f4208d01f1d67f1 /net/sched | |
| parent | 67db8c3ebe92e74e138754162c78276fd263ee50 (diff) | |
net: sched: cls_u32: mark root hnode explicitly
... and produce consistent error on attempt to delete such.
Existing check in u32_delete() is inconsistent - after
tc qdisc add dev eth0 ingress
tc filter add dev eth0 parent ffff: protocol ip prio 100 handle 1: u32 \
divisor 1
tc filter add dev eth0 parent ffff: protocol ip prio 200 handle 2: u32 \
divisor 1
both
tc filter delete dev eth0 parent ffff: protocol ip prio 100 handle 801: u32
and
tc filter delete dev eth0 parent ffff: protocol ip prio 100 handle 800: u32
will fail (at least with refcounting fixes), but the former will complain
about an attempt to remove a busy table, while the latter will recognize
it as root and yield "Not allowed to delete root node" instead.
The problem with the existing check is that several tcf_proto instances
might share the same tp->data and handle-to-hnode lookup will be the same
for all of them. So comparing an hnode to be deleted with tp->root won't
catch the case when one tp is used to try deleting the root of another.
Solution is trivial - mark the root hnodes explicitly upon allocation and
check for that.
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>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/cls_u32.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index f218ccf1e2d9..622f4657da94 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -84,6 +84,7 @@ struct tc_u_hnode { int refcnt; unsigned int divisor; struct idr handle_idr; + bool is_root; struct rcu_head rcu; u32 flags; /* The 'ht' field MUST be the last field in structure to allow for @@ -377,6 +378,7 @@ static int u32_init(struct tcf_proto *tp) root_ht->refcnt++; root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : 0x80000000; root_ht->prio = tp->prio; + root_ht->is_root = true; idr_init(&root_ht->handle_idr); if (tp_c == NULL) { @@ -692,7 +694,7 @@ static int u32_delete(struct tcf_proto *tp, void *arg, bool *last, goto out; } - if (root_ht == ht) { + if (ht->is_root) { NL_SET_ERR_MSG_MOD(extack, "Not allowed to delete root node"); return -EINVAL; } |