Re: [PATCH nft] src: delete the old cache when dumping is interrupted

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Sun, May 14, 2017 at 03:56:12PM +0800, Liping Zhang wrote:
> From: Liping Zhang <zlpnobody@gmail.com>
> 
> When the dumping operation is interrupted, we will restart the
> cache_init(), but unfortunatly, we forget to delete the old cache.
> So in extreme case, we will leak a huge amount of memory.
> 
> Running the following commands can simulate the extreme case:
>   # nft add table t
>   # nft add set t s {type inet_service \;}
>   # for i in $(seq 65000); do
>   nft add element t s {$i}
>   done &
>   # while : ; do
>   time nft list ruleset -nn
>   done
> 
> After a while, oom killer will be triggered:
>   [ 2808.243537] Out of memory: Kill process 16975 (nft) score 649 or
>                  sacrifice child
>   [ 2808.255372] Killed process 16975 (nft) total-vm:1955348kB,
>                  anon-rss:1952120kB, file-rss:0kB, shmem-rss:0kB
>   [ 2858.353729] nft invoked oom-killer: gfp_mask=0x14201ca(GFP_HIGHUSER_
>                  MOVABLE|__GFP_COLD), nodemask=(null),  order=0,
>                  oom_score_adj=0
>   [ 2858.374521] nft cpuset=/ mems_allowed=0
>   ...

Applied, thanks.