# CVE-2022-49911: netfilter: ipset: enforce documented limit to prevent allocating huge memory

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-05-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.11

## Description

In the Linux kernel, the following vulnerability has been resolved: 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/42d20d5e24575c9afa2d66d9a51e7386db9514f5
- https://git.kernel.org/stable/c/a37ef32fe5956fe9248df68f6a61997845ba047e
- https://git.kernel.org/stable/c/510841da1fcc16f702440ab58ef0b4d82a9056b7

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