* [PATCH] netfilter: ipset: enforce documented limit to prevent allocating huge memory
@ 2022-10-27 13:10 Jozsef Kadlecsik
2022-10-27 13:50 ` Daniel Xu
0 siblings, 1 reply; 2+ messages in thread
From: Jozsef Kadlecsik @ 2022-10-27 13:10 UTC (permalink / raw)
To: netfilter-devel; +Cc: Pablo Neira Ayuso, Daniel Xu
Daniel Xu reported that the hash:net,iface type of the ipset subsystem does
not limit adding the same network with different interfaces to a set, which
can lead to huge memory usage or allocation failure.
The quick reproducer is
$ ipset create ACL.IN.ALL_PERMIT hash:net,iface hashsize 1048576 timeout 0
$ for i in $(seq 0 100); do /sbin/ipset add ACL.IN.ALL_PERMIT 0.0.0.0/0,kaf_$i timeout 0 -exist; done
The backtrace when vmalloc fails:
[Tue Oct 25 00:13:08 2022] ipset: vmalloc error: size 1073741848, exceeds total pages
<...>
[Tue Oct 25 00:13:08 2022] Call Trace:
[Tue Oct 25 00:13:08 2022] <TASK>
[Tue Oct 25 00:13:08 2022] dump_stack_lvl+0x48/0x60
[Tue Oct 25 00:13:08 2022] warn_alloc+0x155/0x180
[Tue Oct 25 00:13:08 2022] __vmalloc_node_range+0x72a/0x760
[Tue Oct 25 00:13:08 2022] ? hash_netiface4_add+0x7c0/0xb20
[Tue Oct 25 00:13:08 2022] ? __kmalloc_large_node+0x4a/0x90
[Tue Oct 25 00:13:08 2022] kvmalloc_node+0xa6/0xd0
[Tue Oct 25 00:13:08 2022] ? hash_netiface4_resize+0x99/0x710
<...>
The fix is to enforce the limit documented in the ipset(8) manpage:
> The internal restriction of the hash:net,iface set type is that the same
> network prefix cannot be stored with more than 64 different interfaces
> in a single set.
Reported-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
---
net/netfilter/ipset/ip_set_hash_gen.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index 6e391308431d..3f8853ed32e9 100644
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -61,10 +61,6 @@ tune_bucketsize(u8 curr, u32 multi)
*/
return n > curr && n <= AHASH_MAX_TUNED ? n : curr;
}
-#define TUNE_BUCKETSIZE(h, multi) \
- ((h)->bucketsize = tune_bucketsize((h)->bucketsize, multi))
-#else
-#define TUNE_BUCKETSIZE(h, multi)
#endif
/* A hash bucket */
@@ -936,7 +932,11 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
goto set_full;
/* Create a new slot */
if (n->pos >= n->size) {
- TUNE_BUCKETSIZE(h, multi);
+#ifdef IP_SET_HASH_WITH_MULTI
+ if (h->bucketsize >= AHASH_MAX_TUNED)
+ goto set_full;
+ h->bucketsize = tune_bucketsize(h->bucketsize, multi);
+#endif
if (n->size >= AHASH_MAX(h)) {
/* Trigger rehashing */
mtype_data_next(&h->next, d);
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] netfilter: ipset: enforce documented limit to prevent allocating huge memory
2022-10-27 13:10 [PATCH] netfilter: ipset: enforce documented limit to prevent allocating huge memory Jozsef Kadlecsik
@ 2022-10-27 13:50 ` Daniel Xu
0 siblings, 0 replies; 2+ messages in thread
From: Daniel Xu @ 2022-10-27 13:50 UTC (permalink / raw)
To: Jozsef Kadlecsik; +Cc: netfilter-devel, Pablo Neira Ayuso
On Thu, Oct 27, 2022 at 03:10:22PM +0200, Jozsef Kadlecsik wrote:
> Daniel Xu reported that the hash:net,iface type of the ipset subsystem does
> not limit adding the same network with different interfaces to a set, which
> can lead to huge memory usage or allocation failure.
>
> The quick reproducer is
>
> $ ipset create ACL.IN.ALL_PERMIT hash:net,iface hashsize 1048576 timeout 0
> $ for i in $(seq 0 100); do /sbin/ipset add ACL.IN.ALL_PERMIT 0.0.0.0/0,kaf_$i timeout 0 -exist; done
>
> The backtrace when vmalloc fails:
>
> [Tue Oct 25 00:13:08 2022] ipset: vmalloc error: size 1073741848, exceeds total pages
> <...>
> [Tue Oct 25 00:13:08 2022] Call Trace:
> [Tue Oct 25 00:13:08 2022] <TASK>
> [Tue Oct 25 00:13:08 2022] dump_stack_lvl+0x48/0x60
> [Tue Oct 25 00:13:08 2022] warn_alloc+0x155/0x180
> [Tue Oct 25 00:13:08 2022] __vmalloc_node_range+0x72a/0x760
> [Tue Oct 25 00:13:08 2022] ? hash_netiface4_add+0x7c0/0xb20
> [Tue Oct 25 00:13:08 2022] ? __kmalloc_large_node+0x4a/0x90
> [Tue Oct 25 00:13:08 2022] kvmalloc_node+0xa6/0xd0
> [Tue Oct 25 00:13:08 2022] ? hash_netiface4_resize+0x99/0x710
> <...>
>
> The fix is to enforce the limit documented in the ipset(8) manpage:
>
> > The internal restriction of the hash:net,iface set type is that the same
> > network prefix cannot be stored with more than 64 different interfaces
> > in a single set.
>
> Reported-by: Daniel Xu <dxu@dxuuu.xyz>
> Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Works for me.
Tested-by: Daniel Xu <dxu@dxuuu.xyz>
Thanks,
Daniel
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-10-27 13:10 [PATCH] netfilter: ipset: enforce documented limit to prevent allocating huge memory Jozsef Kadlecsik
2022-10-27 13:50 ` Daniel Xu
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