Premature free of channel context in Linux kernel mac80211
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
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 1 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 3.17 contains a flaw in the wifi mac80211 channel context handling. During an in-place channel context replacement, the old context can be freed while its replacement still points back to it. Later unreserve and switch-finalization paths then follow that stale pointer.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: keep paired old chanctx alive An in-place replacement keeps reciprocal replace_ctx pointers between the old WILL_BE_REPLACED chanctx and the new REPLACES_OTHER chanctx. However, the early free paths only consider assigned and reserved link users when deciding whether to free the old chanctx. That lets the old chanctx be freed too early while the replacement partner still points back to it, either when the last assigned link is released or when that link successfully reassigns to another existing context. Later unreserve and switch-finalization paths can then follow a stale replace_ctx pointer. Keep a paired old chanctx alive until the replacement pair has been torn down. Apply the same check to both __ieee80211_link_release_channel() and ieee80211_link_use_reserved_reassign(). If the replacement is later abandoned, ieee80211_link_unreserve_chanctx() already tears down the pairing before freeing the old chanctx once no users remain.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.17 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 3.17 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 Patch available CNA
Remediation
Upgrade to Linux kernel 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10 or 7.3, depending on the branch in use. Red Hat Enterprise Linux 10 has no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 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 |
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98708
- 2026-10-18 Alias added: GHSA-84vh-fqvc-p664
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score added · Red Hat
- 2026-10-21 Fix available: Linux/Linux@47864a9092fd6f6b3f312d1e5b233ecdc68b1bd8, Linux/[email protected] · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-30 Fix available: Linux/Linux@026ae72fa6d0f7e04951441026be473f22911b87, Linux/Linux@0fba8fbf5ab0bffc1866e5038aaab772d31d1584, Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
References
Other 8
- https://git.kernel.org/stable/c/026ae72fa6d0f7e04951441026be473f22911b87
- https://git.kernel.org/stable/c/624bf5338d8c2f55db455ce4f2543ca4a83fab03
- https://git.kernel.org/stable/c/0fba8fbf5ab0bffc1866e5038aaab772d31d1584
- https://git.kernel.org/stable/c/47864a9092fd6f6b3f312d1e5b233ecdc68b1bd8
- https://git.kernel.org/stable/c/21a688cbeae0e682f03e91f1e7a7eedd60d9d4f2
- https://git.kernel.org/stable/c/1c82d0c5d509179ba2a4edfa096f516aebf960b0
- https://git.kernel.org/stable/c/afd1cdd16a25c7185b812a612ab7d5f2cbd1e086
- https://git.kernel.org/stable/c/3412e9a800786d1dec4a58367db1cba275e7ef11
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Sources
- CVE-2026-98708 · CVE Program
- CVE-2026-98708 · NVD
- FIRST EPSS
- GHSA-84vh-fqvc-p664 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98708 · Red Hat security data · CC BY 4.0
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