Bug 2535242 (CVE-2026-89900)

Summary: CVE-2026-89900 kernel: media: cec: core: Fix kmemleak due to missed rc_free_device() call
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
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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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's media CEC (Consumer Electronics Control) core. A memory leak (kmemleak) can occur because a device deallocation function (`rc_free_device()`) is not called when a CEC device is unbound. This oversight, introduced by a previous code change, prevents the proper release of allocated memory, potentially leading to resource exhaustion or system instability over time.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-16 11:38:53 UTC
In the Linux kernel, the following vulnerability has been resolved:

media: cec: core: Fix kmemleak due to missed rc_free_device() call

The commit dccc0c3ddf8f ("media: rc: fix race between unregister and
urb/irq callbacks") removed the implicit call to rc_free_device() from
rc_unregister_device(). However, the commit missed to remove the NULL
assignment of adap->rc that is now causing rc_free_device() to never be
called on an allocated rc device.

kmemleak reports following after e.g. dw-hdmi unbind:

unreferenced object 0xffff00010ac10000 (size 4096):
  comm "kworker/u16:1", pid 39, jiffies 4294897739
  hex dump (first 32 bytes):
    20 23 4b 0a 01 00 ff ff 08 00 c1 0a 01 00 ff ff   #K.............
    08 00 c1 0a 01 00 ff ff 00 00 00 00 00 00 00 00  ................
  backtrace (crc e11baccc):
    kmemleak_alloc+0x38/0x44
    __kmalloc_cache_noprof+0x4a8/0x5e0
    rc_allocate_device+0x48/0x2a0
    cec_allocate_adapter+0x3ac/0x800
    dw_hdmi_cec_probe+0x264/0x634
    platform_probe+0xc0/0x188
    really_probe+0x4a4/0x8e0
    __driver_probe_device+0x2f8/0x440
    driver_probe_device+0x60/0x160
    __device_attach_driver+0x1a0/0x2a0
    bus_for_each_drv+0x100/0x1a0
    __device_attach+0x174/0x350
    device_initial_probe+0x90/0xb0
    bus_probe_device+0x4c/0x120
    device_add+0xdec/0x116c
    platform_device_add+0x354/0x598

Remove the assignment of adap->rc to NULL to let cec_delete_adapter()
free the allocated rc device after last user of the cec device exits to
fix the kmemleak.