bpf: Fix potential UAF in bpf_netns_link_update_prog
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 5 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix potential UAF in bpf_netns_link_update_prog In bpf_netns_link_update_prog, the checks for old_prog and prog type are currently performed locklessly before acquiring netns_bpf_mutex. This creates a race condition that can lead to a UAF issue. If two threads concurrently execute BPF_LINK_UPDATE on the same netns link, the following execution path can trigger a UAF: CPU0 CPU1 bpf_netns_link_update_prog if (old_prog && old_prog != link->prog) return -EPERM; bpf_netns_link_update_prog if (old_prog && old_prog != link->prog) ... old_prog = xchg(&link->prog, new_prog); bpf_prog_put(old_prog); if (new_prog->type != link->prog->type) <-- trigger UAF Fix this by moving the old_prog and prog->type checks inside the netns_bpf_mutex critical section. Meanwhile, use guard() to simplify lock management and avoid all the goto jumping.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-90393
- 2026-10-03 Alias added: GHSA-9prj-6xm5-hxjf
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score changed · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/d462b5481d77ce7df8a5ff89a699386f00c9214d
- https://git.kernel.org/stable/c/bdddf3e1493ee973619c154a57071ce67f78598b
- https://git.kernel.org/stable/c/79a66fd997d4eecf17302d613194879eb32e0986
- https://git.kernel.org/stable/c/f4ce6803df4095777191d800bebc50219b615ca0
- https://git.kernel.org/stable/c/277168cb9d153ce8e9c3f9275670e32ae61b41d6
- https://git.kernel.org/stable/c/bda86e9f31b9a296b6e64a51c91dc776fc9f613e
- https://git.kernel.org/stable/c/923f559e95b89b33c7e1793b3d8f7f4ec9b2e4b7
- https://git.kernel.org/stable/c/5c5997836381010fc5907b36bc17d3b19407e933
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Sources
- CVE-2026-90393 · CVE Program
- CVE-2026-90393 · NVD
- FIRST EPSS
- GHSA-9prj-6xm5-hxjf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-90393 · Red Hat security data · CC BY 4.0
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