From: Jozsef Kadlecsik kadlec@netfilter.org
[ Upstream commit 510841da1fcc16f702440ab58ef0b4d82a9056b7 ]
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.
Fixes: ccf0a4b7fc68 ("netfilter: ipset: Add bucketsize parameter to all hash types") Reported-by: Daniel Xu dxu@dxuuu.xyz Signed-off-by: Jozsef Kadlecsik kadlec@netfilter.org Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/ipset/ip_set_hash_gen.h | 30 ++++++--------------------- 1 file changed, 6 insertions(+), 24 deletions(-)
diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index 6e391308431d..3adc291d9ce1 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -42,31 +42,8 @@ #define AHASH_MAX_SIZE (6 * AHASH_INIT_SIZE) /* Max muber of elements in the array block when tuned */ #define AHASH_MAX_TUNED 64 - #define AHASH_MAX(h) ((h)->bucketsize)
-/* Max number of elements can be tuned */ -#ifdef IP_SET_HASH_WITH_MULTI -static u8 -tune_bucketsize(u8 curr, u32 multi) -{ - u32 n; - - if (multi < curr) - return curr; - - n = curr + AHASH_INIT_SIZE; - /* Currently, at listing one hash bucket must fit into a message. - * Therefore we have a hard limit here. - */ - 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 */ struct hbucket { struct rcu_head rcu; /* for call_rcu */ @@ -936,7 +913,12 @@ 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; + else if (h->bucketsize < multi) + h->bucketsize += AHASH_INIT_SIZE; +#endif if (n->size >= AHASH_MAX(h)) { /* Trigger rehashing */ mtype_data_next(&h->next, d);