CVE-2026-23298 PUBLISHED

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

Assigner: Linux
Reserved: 13.01.2026 Published: 25.03.2026 Updated: 25.03.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to ab6f075492d37368b4c7b0df7f7fdc2b666887fc (excl.)
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to 13b646eec3ba1131180803f5aaf1fee23540ad8f (excl.)
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to bd85f21a6219aeae4389d700c54f1799f4b814e0 (excl.)
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588 (excl.)
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to c7bc62be6c1a60bb21301692009590b1ffda91d9 (excl.)
  • affected from 9f2d3eae88d26c29d96e42983b755940d9169cd9 to 1e446fd0582ad8be9f6dafb115fc2e7245f9bea7 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.19 is affected
  • unaffected from 0 to 4.19 (excl.)
  • unaffected from 6.1.167 to 6.1.* (incl.)
  • unaffected from 6.6.130 to 6.6.* (incl.)
  • unaffected from 6.12.77 to 6.12.* (incl.)
  • unaffected from 6.18.17 to 6.18.* (incl.)
  • unaffected from 6.19.7 to 6.19.* (incl.)
  • unaffected from 7.0-rc3 to * (incl.)

References