Re: Interesting Rose patch

[f6bvp <f6bvp@free.fr>]

Hi,

Unloading rose module issue due to unmatched dev_put() had also been
previously reported here :

http://marc.info/?l=linux-netdev&m=143389465602786&w=2

and here by f6bvp :

http://marc.info/?l=linux-hams&m=148837252410913&w=4


Bernard


>> Hi,
>>
>> I want to acknowledge here a set of very usefull ROSE patches provided 
>> by richard Stearn.
>>
>> Since years, it has not been possible to set rose0 device down without 
>> creating an endless loop of kernel waiting for rose to become free.
>>
>> Richard found that a number of dev_put(dev) were missing.
>>
>> Applying the following patch subset cured the issue and allowed a clean 
>> rose module removal.
>>
>> The following patches are part of a larger series committed by Richard 
>> but rejected by Dave Miller mostly for format reasons.
>>
>> I selected and checked the minimal changes necessary to cure the 
>> refcount issue.
>>
>> See :
>>
>> http://marc.info/?l=linux-hams&m=146873255413533&w=2
>>
>> Richard does not want to jump in again.
>>
>> So I would appreciate if someone could help us by confirming that this 
>> patch is extremely convenient.
>>
>> Then someone could submit this subset to linux-hams and linux-netdev 
>> referees.
>>
>> 73 de Bernard, f6bvp
>>
>> ----------------------------------------
>>
>>
>> diff -ruN a/net/rose/af_rose.c b/net/rose/af_rose.c
>> --- a/net/rose/af_rose.c        2017-04-03 19:02:14.205800053 +0200
>> +++ b/net/rose/af_rose.c        2017-04-03 12:18:02.290052819 +0200
>> @@ -688,8 +688,10 @@
>>                  rose->source_call = user->call;
>>                  ax25_uid_put(user);
>>          } else {
>> -               if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE))
>> +               if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
>> +                       dev_put(dev);
>>                          return -EACCES;
>> +               }
>>                  rose->source_call   = *source;
>>          }
>>
>> @@ -710,6 +712,7 @@
>>          rose_insert_socket(sk);
>>
>>          sock_reset_flag(sk, SOCK_ZAPPED);
>> +       dev_put(dev);
>>
>>          return 0;
>>   }
>> diff -ruN a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c
>> --- a/net/rose/rose_loopback.c  2017-04-03 19:02:14.206800010 +0200
>> +++ b/net/rose/rose_loopback.c  2017-04-03 12:18:02.291052777 +0200
>> @@ -102,6 +102,7 @@
>>                          if ((dev = rose_dev_get(dest)) != NULL) {
>>                                  if (rose_rx_call_request(skb, dev, 
>> rose_loopback_neigh, lci_o) == 0)
>>                                          kfree_skb(skb);
>> +                               dev_put(dev);
>>                          } else {
>>                                  kfree_skb(skb);
>>                          }