CVE-2026-46151 usb: usblp: fix heap leak in IEEE 1284 device ID via short response
A malicious USB printer can leak uninitialized kernel heap memory to local users via the usblp driver's device ID handling.
- 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-2026-46151?
CVE-2026-46151 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 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 heap, with the leak size chosen by the device.
Fix this up by just zapping the buffer with zeros before each request sent to the device.
Weakness: CWE-401
Which versions are affected by CVE-2026-46151?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46151?
Apply the vendor's patch.
Is CVE-2026-46151 being exploited?
There is no known exploitation of CVE-2026-46151 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88941, BELL-CVE-2026-46151, DEBIAN-CVE-2026-46151, GHSA-589q-vfc2-j9cg, ROOT-OS-DEBIAN-11-CVE-2026-46151, ROOT-OS-DEBIAN-12-CVE-2026-46151 and 3 more.