In the Linux kernel, the following vulnerability has been resolved: usb: typec: thunderbolt: Disable work before freeing tbt on remove… (CVE-2026-89737)
A use-after-free vulnerability in the Linux kernel's USB Type-C Thunderbolt driver was resolved by disabling and draining work items before freeing related references during device removal. The flaw involved work functions that could dereference freed references and potentially requeue themselves, leading to unsafe behavior during teardown.
AI Analysis
Technical Summary
The Linux kernel vulnerability CVE-2026-89737 concerns the usb: typec: thunderbolt driver where the function tbt_altmode_remove() dropped plug and cable references without draining the associated work item tbt->work. Since the work function dereferences these references and can requeue itself on error, this could cause use-after-free conditions. The fix disables and drains tbt->work before dropping references, ensuring any ongoing or future work invocations are prevented during teardown. This issue was identified by an in-house static analysis tool and confirmed by manual code review.
Potential Impact
The vulnerability could lead to use-after-free conditions in the Thunderbolt USB Type-C driver, potentially causing kernel crashes or undefined behavior. No known exploits in the wild have been reported. The impact is limited to affected Linux kernel versions with this driver implementation.
Mitigation Recommendations
A fix is available and has been applied to the Linux kernel source code. Users should update their Linux kernel to a version that includes this patch to mitigate the vulnerability. No additional mitigation steps are indicated.
In the Linux kernel, the following vulnerability has been resolved: usb: typec: thunderbolt: Disable work before freeing tbt on remove… (CVE-2026-89737)
Description
A use-after-free vulnerability in the Linux kernel's USB Type-C Thunderbolt driver was resolved by disabling and draining work items before freeing related references during device removal. The flaw involved work functions that could dereference freed references and potentially requeue themselves, leading to unsafe behavior during teardown.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability CVE-2026-89737 concerns the usb: typec: thunderbolt driver where the function tbt_altmode_remove() dropped plug and cable references without draining the associated work item tbt->work. Since the work function dereferences these references and can requeue itself on error, this could cause use-after-free conditions. The fix disables and drains tbt->work before dropping references, ensuring any ongoing or future work invocations are prevented during teardown. This issue was identified by an in-house static analysis tool and confirmed by manual code review.
Potential Impact
The vulnerability could lead to use-after-free conditions in the Thunderbolt USB Type-C driver, potentially causing kernel crashes or undefined behavior. No known exploits in the wild have been reported. The impact is limited to affected Linux kernel versions with this driver implementation.
Mitigation Recommendations
A fix is available and has been applied to the Linux kernel source code. Users should update their Linux kernel to a version that includes this patch to mitigate the vulnerability. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-vj4x-g937-4233
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89737"]
Threat ID: 6aa49ffa55bf5e2cf5a865ca
Added to database: 09/12/2026, 00:42:34 UTC
Last enriched: 09/12/2026, 00:49:32 UTC
Last updated: 09/12/2026, 00:49:32 UTC
Views: 1
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