Re: [PATCH net 1/1] net sched actions: fix dumping which requires several messages to user space

[David Miller <davem@davemloft.net>]

From: Craig Dillabaugh <cdillaba@mojatatu.com>
Date: Mon, 26 Mar 2018 14:58:32 -0400

>     Fixes a bug in the tcf_dump_walker function that can cause some actions
>     to not be reported when dumping a large number of actions. This issue
>     became more aggrevated when cookies feature was added. In particular
>     this issue is manifest when large cookie values are assigned to the
>     actions and when enough actions are created that the resulting table
>     must be dumped in multiple batches.
> 
>     The number of actions returned in each batch is limited by the total
>     number of actions and the memory buffer size.  With small cookies
>     the numeric limit is reached before the buffer size limit, which avoids
>     the code path triggering this bug. When large cookies are used buffer
>     fills before the numeric limit, and the erroneous code path is hit.
> 
>     For example after creating 32 csum actions with the cookie
>     aaaabbbbccccdddd
 ...
>     Note that the action with index 27 is omitted from the report.
> 
> Fixes: 4b3550ef530c ("[NET_SCHED]: Use nla_nest_start/nla_nest_end")"
> Signed-off-by: Craig Dillabaugh <cdillaba@mojatatu.com>

Applied and queued up for -stable.