On 25/01/2022 10:24, Nikolay Aleksandrov wrote:
> On 25/01/2022 08:19, Benjamin Poirier wrote:
>> Specifying ifindex in a RTM_GETVLAN dump leads to an infinite repetition
>> of the same entries. netlink_dump() normally calls the dump function
>> repeatedly until it returns 0 which br_vlan_rtm_dump() never does in
>> that case.
>>
>> Fixes: 8dcea187088b ("net: bridge: vlan: add rtm definitions and dump support")
>> Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxxxx>
>> ---
>> net/bridge/br_vlan.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
> [snip]
>>
>> diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
>> index 84ba456a78cc..2e606f2b9a4d 100644
>> --- a/net/bridge/br_vlan.c
>> +++ b/net/bridge/br_vlan.c
>> @@ -2013,7 +2013,7 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
>> dump_flags = nla_get_u32(dtb[BRIDGE_VLANDB_DUMP_FLAGS]);
>>
>> rcu_read_lock();
>> - if (bvm->ifindex) {
>> + if (bvm->ifindex && !s_idx) {
>> dev = dev_get_by_index_rcu(net, bvm->ifindex);
>> if (!dev) {
>> err = -ENODEV;
>> @@ -2022,7 +2022,9 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
>> err = br_vlan_dump_dev(dev, skb, cb, dump_flags);
>> if (err && err != -EMSGSIZE)
>> goto out_err;
>> - } else {
>> + else if (!err)
>> + idx++;
>> + } else if (!bvm->ifindex) {
>> for_each_netdev_rcu(net, dev) {
>> if (idx < s_idx)
>> goto skip;
>
> Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx>
Actually I'd prefer an alternative that would encapsulate handling the single
device dump in its block, avoid all the "else if"s and is simpler (untested):
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 84ba456a78cc..43201260e37b 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -2020,7 +2020,8 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
goto out_err;
}
err = br_vlan_dump_dev(dev, skb, cb, dump_flags);
- if (err && err != -EMSGSIZE)
+ /* if the dump completed without an error we return 0 here */
+ if (err != -EMSGSIZE)
goto out_err;
} else {
for_each_netdev_rcu(net, dev) {
