Bug 2436756 (CVE-2026-23061)

Summary: CVE-2026-23061 kernel: Linux kernel: Denial of Service in kvaser_usb CAN driver due to memory leak
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's kvaser_usb Controller Area Network (CAN) driver. A local, low-privileged user could exploit a memory leak in the kvaser_usb_read_bulk_callback() function. This occurs because USB Request Blocks (URBs) are not properly unanchored and freed, leading to memory exhaustion and a denial of service.
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Description OSIDB Bzimport 2026-02-04 17:01:50 UTC
In the Linux kernel, the following vulnerability has been resolved:

can: kvaser_usb: kvaser_usb_read_bulk_callback(): fix URB memory leak

Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb:
gs_usb_receive_bulk_callback(): fix URB memory leak").

In kvaser_usb_set_{,data_}bittiming() -> kvaser_usb_setup_rx_urbs(), the
URBs for USB-in transfers are allocated, added to the dev->rx_submitted
anchor and submitted. In the complete callback
kvaser_usb_read_bulk_callback(), the URBs are processed and resubmitted. In
kvaser_usb_remove_interfaces() the URBs are freed by calling
usb_kill_anchored_urbs(&dev->rx_submitted).

However, this does not take into account that the USB framework unanchors
the URB before the complete function is called. This means that once an
in-URB has been completed, it is no longer anchored and is ultimately not
released in usb_kill_anchored_urbs().

Fix the memory leak by anchoring the URB in the
kvaser_usb_read_bulk_callback() to the dev->rx_submitted anchor.