Evidence-led vulnerability intelligence · 2026-07-19 21:47 IST

CVE-2026-64131

In the Linux kernel, the following vulnerability has been resolved: mm/memory: fix spurious warning when unmapping device-private/exclusive pages Device private and exclusive entries are only supported for anonymous folios. This condition is tested in __migrate_device_pages() and make_device_exclusive() using folio_test_anon(). However the unmap path tests this assumption using vma_is_anonymous(). This is wrong because whilst anonymous VMAs can only contain folios where folio_test_anon() is true the opposite relation does not hold. A folio for which folio_test_anon() is true does not imply vma_is_anonymous() is true. Such a condition can occur if for example a folio is part of a private filebacked mapping. In this case vma_is_anonymous() is false as the mapping is filebacked, but folio_test_anon() may be true, thus permitting devices to migrate the folio to device private memory. This can lead to the following spurious warnings during process teardown: [ 772.737706] ------------[ cut here ]------------ [ 772.739201] WARNING: mm/memory.c:1754 at unmap_page_range.cold+0x26/0x18a, CPU#17: hmm-tests/2041 [ 772.742050] Modules linked in: test_hmm nvidia_uvm(O) nvidia(O) [ 772.743959] CPU: 17 UID: 0 PID: 2041 Comm: hmm-tests Tainted: G W O 7.0.0+ #387 PREEMPT(full) [ 772.747104] Tainted: [W]=WARN, [O]=OOT_MODULE [ 772.748509] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 772.752117] RIP: 0010:unmap_page_range.cold+0x26/0x18a [ 772.753780] Code: 7e fe ff ff 48 89 4c 24 78 4c 89 44 24 38 e8 f2 ff b1 00 48 8b 4c 24 78 4c 8b 44 24 38 48 8b 44 24 18 48 83 78 48 00 74 04 90 <0f> 0b 90 48 89 ca b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 2a 80 3c 02 [ 772.759602] RSP: 0018:ffff888112607550 EFLAGS: 00010286 [ 772.761310] RAX: ffff88811bbf4dc0 RBX: dffffc0000000000 RCX: ffffea03e9bfffd8 [ 772.763583] RDX: 1ffff1102377e9c1 RSI: 0000000000000008 RDI: ffff88811bbf4e08 [ 772.765914] RBP: 0000000000000006 R08: ffff8881059f7448 R09: ffffed10224c0e68 [ 772.768184] R10: ffff888112607347 R11: 0000000000000001 R12: 0000000000000001 [ 772.770461] R13: ffffea03e9bfffc0 R14: ffff888112607908 R15: ffffea03e9bfffc0 [ 772.772782] FS: 00007f327caa2780(0000) GS:ffff888427b7d000(0000) knlGS:0000000000000000 [ 772.775328] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 772.777187] CR2: 00007f327ca89000 CR3: 00000001994d5000 CR4: 00000000000006f0 [ 772.779135] Call Trace: [ 772.779792] <TASK> [ 772.780317] ? dmirror_interval_invalidate+0x1a3/0x290 [test_hmm] [ 772.781873] ? vm_normal_page_pud+0x2b0/0x2b0 [ 772.782992] ? __rwlock_init+0x150/0x150 [ 772.784006] ? lock_release+0x216/0x2b0 [ 772.785008] ? __mmu_notifier_invalidate_range_start+0x505/0x6e0 [ 772.786522] ? lock_release+0x216/0x2b0 [ 772.787498] ? unmap_single_vma+0xb6/0x210 [ 772.788573] unmap_vmas+0x27d/0x520 [ 772.789506] ? unmap_single_vma+0x210/0x210 [ 772.790607] ? mas_update_gap.part.0+0x620/0x620 [ 772.791834] unmap_region+0x19e/0x350 [ 772.792769] ? remove_vma+0x130/0x130 [ 772.793684] ? mas_alloc_nodes+0x1f2/0x300 [ 772.794730] vms_complete_munmap_vmas+0x8c1/0xe20 [ 772.795926] ? unmap_region+0x350/0x350 [ 772.796917] do_vmi_align_munmap+0x36a/0x4e0 [ 772.798018] ? lock_release+0x216/0x2b0 [ 772.799024] ? vma_shrink+0x620/0x620 [ 772.799983] do_vmi_munmap+0x150/0x2c0 [ 772.800939] __vm_munmap+0x161/0x2c0 [ 772.801872] ? expand_downwards+0xd60/0xd60 [ 772.802948] ? clockevents_program_event+0x1ef/0x540 [ 772.804217] ? lock_release+0x216/0x2b0 [ 772.805158] __x64_sys_munmap+0x59/0x80 [ 772.805776] do_syscall_64+0xfc/0x670 [ 772.806336] ? irqentry_exit+0xda/0x580 [ 772.806976] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 772.807772] RIP: 0033:0x7f327cbb2717 [ 772.808323] Code: 73 01 c3 48 8b 0d f9 76 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ---truncated---

MEDIUM · 5.5LinuxmacOS / Apple

Executive briefing

The source record describes: In the Linux kernel, the following vulnerability has been resolved: mm/memory: fix spurious warning when unmapping device-private/exclusive pages Device private and exclusive entries are only supported for anonymous folios. This condition is tested in __migrate_device_pages() and make_device_exclusive() using folio_test_anon(). However the unmap path tests this assumption using vma_is_anonymous(). This is wrong because whilst anonymous VMAs can only contain folios where folio_test_anon() is true the opposite relation does not hold. A folio for which folio_test_anon() is true does not imply vma_is_anonymous() is true. Such a condition can occur if for example a folio is part of a private filebacked mapping. In this case vma_is_anonymous() is false as the mapping is filebacked, but folio_test_anon() may be true, thus permitting devices to migrate the folio to device private memory. This can lead to the following spurious warnings during process teardown: [ 772.737706] ------------[ cut here ]------------ [ 772.739201] WARNING: mm/memory.c:1754 at unmap_page_range.cold+0x26/0x18a, CPU#17: hmm-tests/2041 [ 772.742050] Modules linked in: test_hmm nvidia_uvm(O) nvidia(O) [ 772.743959] CPU: 17 UID: 0 PID: 2041 Comm: hmm-tests Tainted: G W O 7.0.0+ #387 PREEMPT(full) [ 772.747104] Tainted: [W]=WARN, [O]=OOT_MODULE [ 772.748509] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 772.752117] RIP: 0010:unmap_page_range.cold+0x26/0x18a [ 772.753780] Code: 7e fe ff ff 48 89 4c 24 78 4c 89 44 24 38 e8 f2 ff b1 00 48 8b 4c 24 78 4c 8b 44 24 38 48 8b 44 24 18 48 83 78 48 00 74 04 90 <0f> 0b 90 48 89 ca b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 2a 80 3c 02 [ 772.759602] RSP: 0018:ffff888112607550 EFLAGS: 00010286 [ 772.761310] RAX: ffff88811bbf4dc0 RBX: dffffc0000000000 RCX: ffffea03e9bfffd8 [ 772.763583] RDX: 1ffff1102377e9c1 RSI: 0000000000000008 RDI: ffff88811bbf4e08 [ 772.765914] RBP: 0000000000000006 R08: ffff8881059f7448 R09: ffffed10224c0e68 [ 772.768184] R10: ffff888112607347 R11: 0000000000000001 R12: 0000000000000001 [ 772.770461] R13: ffffea03e9bfffc0 R14: ffff888112607908 R15: ffffea03e9bfffc0 [ 772.772782] FS: 00007f327caa2780(0000) GS:ffff888427b7d000(0000) knlGS:0000000000000000 [ 772.775328] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 772.777187] CR2: 00007f327ca89000 CR3: 00000001994d5000 CR4: 00000000000006f0 [ 772.779135] Call Trace: [ 772.779792] <TASK> [ 772.780317] ? dmirror_interval_invalidate+0x1a3/0x290 [test_hmm] [ 772.781873] ? vm_normal_page_pud+0x2b0/0x2b0 [ 772.782992] ? __rwlock_init+0x150/0x150 [ 772.784006] ? lock_release+0x216/0x2b0 [ 772.785008] ? __mmu_notifier_invalidate_range_start+0x505/0x6e0 [ 772.786522] ? lock_release+0x216/0x2b0 [ 772.787498] ? unmap_single_vma+0xb6/0x210 [ 772.788573] unmap_vmas+0x27d/0x520 [ 772.789506] ? unmap_single_vma+0x210/0x210 [ 772.790607] ? mas_update_gap.part.0+0x620/0x620 [ 772.791834] unmap_region+0x19e/0x350 [ 772.792769] ? remove_vma+0x130/0x130 [ 772.793684] ? mas_alloc_nodes+0x1f2/0x300 [ 772.794730] vms_complete_munmap_vmas+0x8c1/0xe20 [ 772.795926] ? unmap_region+0x350/0x350 [ 772.796917] do_vmi_align_munmap+0x36a/0x4e0 [ 772.798018] ? lock_release+0x216/0x2b0 [ 772.799024] ? vma_shrink+0x620/0x620 [ 772.799983] do_vmi_munmap+0x150/0x2c0 [ 772.800939] __vm_munmap+0x161/0x2c0 [ 772.801872] ? expand_downwards+0xd60/0xd60 [ 772.802948] ? clockevents_program_event+0x1ef/0x540 [ 772.804217] ? lock_release+0x216/0x2b0 [ 772.805158] __x64_sys_munmap+0x59/0x80 [ 772.805776] do_syscall_64+0xfc/0x670 [ 772.806336] ? irqentry_exit+0xda/0x580 [ 772.806976] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 772.807772] RIP: 0033:0x7f327cbb2717 [ 772.808323] Code: 73 01 c3 48 8b 0d f9 76 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ---truncated--- The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Moderate Evidence-derived, not an exploitability verdict

Severity & attack characteristics

5.5 / 10 · 3.1

CVSS vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack vectorL
Attack complexityL
Privileges requiredL
User interactionN
ScopeU
Confidentiality impactN
Integrity impactN
Availability impactH

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Weakness classification

NVD-CWE-noinfo

Affected products and versions

Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.

VendorProductVersion evidence
linuxlinux_kernelfrom (inclusive) 6.19; before 7.0.11 · CPE version 7.1 · CPE version 7.1 · CPE version 7.1 · CPE version 7.1

Remediation & validation

  1. Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
  2. Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
  3. Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
  4. Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

Open NVD record ← Back to CVE Watch

Threat intelligence, made actionable · CVE data sourced from the NVD