]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
netfilter: ipset: enforce documented limit to prevent allocating huge memory
authorJozsef Kadlecsik <kadlec@netfilter.org>
Wed, 2 Nov 2022 09:40:47 +0000 (10:40 +0100)
committerPablo Neira Ayuso <pablo@netfilter.org>
Wed, 2 Nov 2022 18:22:23 +0000 (19:22 +0100)
commit510841da1fcc16f702440ab58ef0b4d82a9056b7
tree0ae9ae1a55f8b0b01e3783c9caa4b306ddf7f396
parentcbc1dd5b659f5a2c3cba88b197b7443679bb35a0
netfilter: ipset: enforce documented limit to prevent allocating huge memory

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>
net/netfilter/ipset/ip_set_hash_gen.h