Bug 2464380 (CVE-2026-31701)

Summary: CVE-2026-31701 kernel: ALSA: caiaq: take a reference on the USB device in create_card()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Advanced Linux Sound Architecture (ALSA) caiaq driver. This vulnerability arises from improper handling of Universal Serial Bus (USB) device references. When a USB device is disconnected, the driver may attempt to access memory that has already been freed, a condition known as use-after-free. This can lead to system instability, crashes, or potentially allow a local attacker to execute arbitrary code.
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Description OSIDB Bzimport 2026-05-01 15:03:27 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ALSA: caiaq: take a reference on the USB device in create_card()

The caiaq driver stores a pointer to the parent USB device in
cdev->chip.dev but never takes a reference on it. The card's
private_free callback, snd_usb_caiaq_card_free(), can run
asynchronously via snd_card_free_when_closed() after the USB
device has already been disconnected and freed, so any access to
cdev->chip.dev in that path dereferences a freed usb_device.

On top of the refcounting issue, the current card_free implementation
calls usb_reset_device(cdev->chip.dev). A reset in a free callback
is inappropriate: the device is going away, the call takes the
device lock in a teardown context, and the reset races with the
disconnect path that the callback is already cleaning up after.

Take a reference on the USB device in create_card() with
usb_get_dev(), drop it with usb_put_dev() in the free callback,
and remove the usb_reset_device() call.
Comment 1 Keith Grant 2026-05-01 19:47:44 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050119-CVE-2026-31701-fb7c@gregkh/T