CVE-2026-46151
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability has been identified in the usblp driver in the Linux kernel, leading to a heap leak in controlling IEEE 1284 devices. The issue arises when a faulty printer can leave stale data in memory due to improper data transfer.
Risk Assessment
Organizations may be exposed to memory data leaks, potentially leading to the disclosure of sensitive information. If exploited, an attacker could gain access to unauthorized data.
Recommendation
It is recommended to update the Linux kernel to a version that includes the fix, which zeroes the buffer before each request sent to the device. Additionally, monitoring and auditing USB devices can help identify potential threats.
Original NVD description (English source)
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.