Bug 2451227 (CVE-2026-23298)

Summary: CVE-2026-23298 kernel: can: ucan: Fix infinite loop from zero-length messages
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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 CAN (Controller Area Network) ucan driver. This vulnerability allows a connected ucan device to send a message with a zero-length field. Such a message can trigger an infinite loop within the driver, causing the system to hang. This ultimately leads to a denial of service (DoS), making the system unresponsive.
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Description OSIDB Bzimport 2026-03-25 11:05:47 UTC
In the Linux kernel, the following vulnerability has been resolved:

can: ucan: Fix infinite loop from zero-length messages

If a broken ucan device gets a message with the message length field set
to 0, then the driver will loop for forever in
ucan_read_bulk_callback(), hanging the system.  If the length is 0, just
skip the message and go on to the next one.

This has been fixed in the kvaser_usb driver in the past in commit
0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in
command parsers"), so there must be some broken devices out there like
this somewhere.