Bug 2535401 (CVE-2026-89899)

Summary: CVE-2026-89899 kernel: media: cec: disable delayed work before freeing an interrupted transmit
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's Consumer Electronics Control (CEC) subsystem. This vulnerability occurs when a transmit operation is interrupted, leading to a delayed work item remaining active after its associated data has been freed. A local attacker could potentially exploit this use-after-free condition to cause a denial of service or potentially achieve arbitrary code execution.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-16 12:40:58 UTC 
In the Linux kernel, the following vulnerability has been resolved:

media: cec: disable delayed work before freeing an interrupted transmit

cec_transmit_msg_fh() drops adap->lock to wait for a blocking transmit in
wait_for_completion_killable(). If that wait is interrupted by a signal,
cancel_delayed_work_sync() can run before the CEC kthread arms the reply
timeout via schedule_delayed_work(&data->work) in cec_transmit_done_ts().
The work is then armed after the cancel, and the data is freed with its
delayed_work still pending:

  ODEBUG: free active (active state 0) object: ... hint: cec_wait_timeout

Use disable_delayed_work_sync(): it cancels the work and disables it, so
the later schedule_delayed_work() becomes a no-op and the work cannot be
re-armed. The data is freed right after, so it need not be re-enabled.
Comment 1 Mauro Matteo Cascella 2026-09-17 09:53:15 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89899.mbox