CVE-2026-46167 usb: usblp: fix uninitialized heap leak via LPGETSTATUS ioctl
A malicious USB printer can leak uninitialized kernel heap memory to local users via the LPGETSTATUS ioctl in the usblp driver.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46167?
CVE-2026-46167 is a medium-severity vulnerability in Linux kernel, published on 28 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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 is no "leak" of information happening.
Weakness: CWE-908
Which versions are affected by CVE-2026-46167?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46167?
Apply the vendor's patch.
Is CVE-2026-46167 being exploited?
There is no known exploitation of CVE-2026-46167 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88911, BELL-CVE-2026-46167, DEBIAN-CVE-2026-46167, GHSA-vq8g-vcx9-rmc5, ROOT-OS-DEBIAN-11-CVE-2026-46167, ROOT-OS-DEBIAN-12-CVE-2026-46167 and 3 more.