Re: nft segfaults listing huge sets

[Oleksandr Natalenko <oleksandr@natalenko.name>]

nftables: 0.7
kernel: 4.8 and 4.9.

02.01.2017 11:12, Oleksandr Natalenko написав:
> /* Please CC me, I'm not subscribed to ML */
> 
> Hello.
> 
> I'm trying to replace ipset+iptables setup with pure nft for 200+
> thousand of subnets.
> 
> For the list of subnets I create a set in a file:
> 
> ===
> add table inet filter
> add set inet filter p2p-paranoid { type ipv4_addr; flags interval; }
> add element inet filter p2p-paranoid {
> 1.0.4.0/22,
> 1.0.64.0/18,
> ...
> here goes 200+ thousand of lines
> ...
> 223.255.128.0/18,
> 223.255.241.132,
> }
> ===
> 
> Then I apply this file by "nft -f file". This works fine.
> 
> Then I try to list ruleset with "nfs list ruleset", but get segfault:
> 
> ===
> Starting program: /usr/bin/nft list ruleset
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x000000000041ef06 in interval_map_decompose (set=0x6f26080) at 
> segtree.c:617
> 617     segtree.c: No such file or directory.
> #0  0x000000000041ef06 in interval_map_decompose (set=0x6f26080) at
> segtree.c:617
> #1  0x0000000000418449 in netlink_get_setelems
> (ctx=ctx@entry=0x7fffffff5260, h=h@entry=0x65caa0,
>     loc=0x43cf00 <internal_location>, set=set@entry=0x65ca90) at 
> netlink.c:1603
> #2  0x0000000000408119 in cache_init_objects (cmd=CMD_LIST,
> ctx=0x7fffffff5260) at rule.c:84
> #3  cache_init (msgs=0x7fffffffe400, cmd=CMD_LIST) at rule.c:130
> #4  cache_update (cmd=cmd@entry=CMD_LIST, msgs=0x7fffffffe400) at 
> rule.c:147
> #5  0x0000000000411717 in cmd_evaluate_list (cmd=0x65c730,
> ctx=0x7fffffffe9f8) at evaluate.c:2793
> #6  cmd_evaluate (ctx=ctx@entry=0x7fffffffe9f8, cmd=0x65c730) at 
> evaluate.c:3048
> #7  0x000000000042849d in nft_parse (scanner=scanner@entry=0x65c4b0,
> state=state@entry=0x7fffffffe410) at parser_bison.y:626
> #8  0x00000000004064c6 in nft_run (scanner=scanner@entry=0x65c4b0,
> state=state@entry=0x7fffffffe410,
>     msgs=msgs@entry=0x7fffffffe400) at main.c:230
> #9  0x00000000004069c2 in main (argc=<optimized out>,
> argv=0x7fffffffec48) at main.c:361
> ===
> 
> The same applies to "nft flush ruleset".
> 
> According to strace, it seems, nft runs out of stack. Here is the tail
> of strace output:
> 
> ===
> brk(0x10b7c000)                         = 0x10b7c000
> brk(0x10b9d000)                         = 0x10b9d000
> brk(0x10bbe000)                         = 0x10bbe000
> brk(0x10bdf000)                         = 0x10bdf000
> brk(0x10c00000)                         = 0x10c00000
> brk(0x10c21000)                         = 0x10c21000
> brk(0x10c42000)                         = 0x10c42000
> brk(0x10c63000)                         = 0x10c63000
> --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, 
> si_addr=0x7fffb6554b18} ---
> +++ killed by SIGSEGV (core dumped) +++
> ===
> 
> The amount of brk() calls is ~1900.
> 
> Could that be addressed, and should I provide more info?
> 
> Thanks.
> 
> Regards,
>   Oleksandr