CVE-2026-46151

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

usb: usblp: fix heap leak in IEEE 1284 device ID via short response

usblp_ctrl_msg() collapses the usb_control_msg() return value to

0/-errno, discarding the actual number of bytes transferred. A broken

printer can complete the GET_DEVICE_ID control transfer short and the

driver has no way to know.

usblp_cache_device_id_string() reads the 2-byte big-endian length prefix

from the response and trusts it (clamped only to the buffer bounds).

The buffer is kmalloc(1024) at probe time. A device that sends exactly

two bytes (e.g. 0x03 0xFF, claiming a 1023-byte ID) leaves

device_id_string[2..1022] holding stale kmalloc heap.

That stale data is then exposed:

- via the ieee1284_id sysfs attribute (sprintf("%s", buf+2), truncated

at the first NUL in the stale heap), and

- via the IOCNR_GET_DEVICE_ID ioctl, which copy_to_user()s the full

claimed length regardless of NULs, up to 1021 bytes of uninitialized

hea

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References