CVE-2026-46167

Technical Description

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

usb: usblp: fix uninitialized heap leak via LPGETSTATUS ioctl

Just like in a previous problem in this driver, usblp_ctrl_msg() will

collapse the usb_control_msg() return value to 0/-errno, discarding the

actual number of bytes transferred.

Ideally that short command should be detected and error out, but many

printers are known to send "incorrect" responses back so we can't just

do that.

statusbuf is kmalloc(8) at probe time and never filled before the first

LPGETSTATUS ioctl.

usblp_read_status() requests 1 byte. If a malicious printer responds

with zero bytes, *statusbuf is one byte of stale kmalloc heap,

sign-extended into the local int status, which the LPGETSTATUS path then

copy_to_user()s directly to the ioctl caller.

Fix this all by just zapping out the memory buffer when allocated at

probe time. If a later call does a short read, the data will be

identical to what the device sent it the last time, so there

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References