VYPR
← All advisories
Medium severity5.5NVD Advisory· Published Nov 7, 2024· Updated Jun 17, 2026

CVE-2024-50163

CVE-2024-50163

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

78

Patches

Vulnerability mechanics

References

6

News mentions

0

No linked articles in our index yet.