CVEvulnerability
CVE-2026-98433
- Status
- Received
- Published
- 2026-10-18
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/0a416ee20bcccddf91ca5b63696a23b9d11d73aa git.kernel.org
- https://git.kernel.org/stable/c/8f3b7746874b39fc20e0363c9076c7787d4765ba git.kernel.org
- https://git.kernel.org/stable/c/a933d7024359e2e566b07903d1294b84f90482ae git.kernel.org
- https://git.kernel.org/stable/c/c41088b2765af1e97e7bb05f906ae1823eca0388 git.kernel.org
- https://git.kernel.org/stable/c/dfb84274932737e338ff5eb27f34b4c8ecb01b50 git.kernel.org
- https://git.kernel.org/stable/c/ed2f2ff63cb7e71204096e765c6d02c3b6974b95 git.kernel.org
- https://git.kernel.org/stable/c/f3d4b2fc30c97cf8e6f8b880d2de9c17ecac7f5b git.kernel.org
- https://git.kernel.org/stable/c/fcbff8008b0e08cd53b611bd0ff7e01f5b962f80 git.kernel.org