CVE-2026-90060: ALSA: control: Don't add invalid kcontrols to LED layer
In the Linux kernel, the following vulnerability has been resolved:
ALSA: control: Don't add invalid kcontrols to LED layer
The kcontrol LED state layer tries to track the all associated kcontrol elements with naive assumptions that they are readable. But one can create a write-only element that has no get callback (even a user element can do it), and this may lead to a NULL dereference at the call chain of sndctllednotify(), as found by syzkaller.
For avoiding the Oops, add a sanity check of the kcontrol's info and get callbacks, and just skip the invalid kcontrols before assigning the kctl to the LED layer.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.190-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.188 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.110 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.52 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.2.6
Event History
Frequently Asked Questions
What conditions are required to trigger the crash?
A write-only ALSA control element without a get callback must be associated with the kcontrol LED state layer. When snd_ctl_led_notify() handles that control, the layer can dereference a NULL callback.
Can user-created ALSA controls be involved?
Yes. The description states that even a user element can be created as write-only with no get callback, making it an invalid control for LED-layer tracking.
What does the fix do?
The fix validates the control's info and get callbacks before assigning it to the LED layer. Controls that do not meet those requirements are skipped, preventing the NULL dereference.