Expired Pointer Dereference Affecting kernel-uki-virt package, versions *
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Test your applications- Snyk IDSNYK-CENTOS10-KERNELUKIVIRT-19251364
- published25 Aug 2026
- disclosed22 Aug 2026
Introduced: 22 Aug 2026
NewCVE-2026-74639 (opens in a new tab)How to fix?
There is no fixed version for Centos:10 kernel-uki-virt.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-uki-virt package and not the kernel-uki-virt package as distributed by Centos.
See How to fix? for Centos:10 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: us144mkii: re-anchor capture URBs on resubmission
capture_urb_complete() resubmits each capture URB without anchoring it:
usb_get_urb(urb);
ret = usb_submit_urb(urb, GFP_ATOMIC);
Anchoring is a property of a submission, not of the URB. The giveback path calls usb_unanchor_urb() before urb->complete(), so an URB resubmitted from its own completion handler is off the anchor. The capture URBs are anchored once, at stream start, so from the first completion onward tascam->capture_anchor is empty.
tascam_free_urbs(), tascam_disconnect(), tascam_suspend() and the stop-work path all call usb_kill_anchored_urbs(&tascam->capture_anchor) to reap the capture URBs before anything is freed. With the anchor empty those calls return immediately and the URBs stay queued on the host controller.
tascam_free_urbs() then returns the capture transfer buffers with usb_free_coherent(), and snd_card_free() releases the snd_card allocation that embeds tascam (card->private_data). The controller completes the queued URBs afterwards, writing device-supplied data into the freed transfer buffer, and capture_urb_complete() dereferences the freed driver object.
KASAN on 7.2.0-rc5 (arm64):
BUG: KASAN: slab-use-after-free in dummy_timer Write of size 512 at addr ffff000015b62000 __asan_memcpy dummy_timer hrtimer_run_softirq Allocated by task 64: usb_alloc_coherent tascam_alloc_urbs tascam_probe Freed by task 170: usb_free_coherent tascam_free_urbs tascam_disconnect usb_unbind_interface
BUG: KASAN: slab-use-after-free in capture_urb_complete Read of size 4 at addr ffff0000170ee878 Freed by task 170: release_card_device snd_card_free tascam_disconnect
Restore the usb_anchor_urb() between the reference count bump and the resubmission. That also makes the handler's usb_unanchor_urb() failure arm meaningful again and restores usb_kill_anchored_urbs() as a barrier on the disconnect, suspend and stop-work paths.
The anchoring was removed on the premise that the URB is already anchored from the initial submission, which does not hold once the first giveback has run.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2521467
- https://access.redhat.com/security/cve/CVE-2026-74639
- https://git.kernel.org/stable/c/2615f0fb90df8cf5a96133ca4be74294ed288604
- https://git.kernel.org/stable/c/7779249561d14b8a17c0c83783225794e24a587d
- https://git.kernel.org/stable/c/a5548ce916594c811bd90ce33d67baa3557a6791