p PatchFirst

CVE-2021-47639

CVE-2021-47639 · KVM: x86/mmu: Zap _all_ roots when unmapping gfn range in TDP MMU

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Zap _all_ roots when unmapping gfn range in TDP MMU Zap both valid and invalid roots when zapping/unmapping a gfn range, as KVM must ensure it holds no references to the freed page after returning from the unmap operation. Most notably, the TDP MMU doesn't zap invalid roots in mmu_notifier callbacks. This leads to use-after-free and other issues if the mmu_notifier runs to completion while an invalid root zapper yields as KVM fails to honor the requirement that there must be _no_ references to the page after the mmu_notifier returns. The bug is most easily reproduced by hacking KVM to cause a collision between set_nx_huge_pages() and kvm_mmu_notifier_release(), but the bug exists between kvm_mmu_notifier_invalidate_range_start() and memslot updates as well. Invalidating a root ensures pages aren't accessible by the guest, and KVM won't read or write page data itself, but KVM will trigger e.g. kvm_set_pfn_dirty() when zapping SPTEs, and thus completing a zap of an invalid root _after_ the mmu_notifier returns is fatal. WARNING: CPU: 24 PID: 1496 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:173 [kvm] RIP: 0010:kvm_is_zone_device_pfn+0x96/0xa0 [kvm] Call Trace: <TASK> kvm_set_pfn_dirty+0xa8/0xe0 [kvm] __handle_changed_spte+0x2ab/0x5e0 [kvm] __handle_changed_spte+0x2ab/0x5e0 [kvm] __handle_changed_spte+0x2ab/0x5e0 [kvm] zap_gfn_range+0x1f3/0x310 [kvm] kvm_tdp_mmu_zap_invalidated_roots+0x50/0x90 [kvm] kvm_mmu_zap_all_fast+0x177/0x1a0 [kvm] set_nx_huge_pages+0xb4/0x190 [kvm] param_attr_store+0x70/0x100 module_attr_store+0x19/0x30 kernfs_fop_write_iter+0x119/0x1b0 new_sync_write+0x11c/0x1b0 vfs_write+0x1cc/0x270 ksys_write+0x5f/0xe0 do_syscall_64+0x38/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK>

CVSS 7.8 · High · EPSS 0.3% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • linux

    Versions
    • ≥ b7cccd397f310739fb85383033e95580f99927e0, < af47248407c0c5ae52a752af1ab5ce5b0db91502: Affected (git)
    • ≥ b7cccd397f310739fb85383033e95580f99927e0, < 0c8a8da182d4333d9bbb9131d765145568c847b2: Affected (git)
    • ≥ b7cccd397f310739fb85383033e95580f99927e0, < 8cf6f98ab1d16d5e607635a0c21c4231eb15367e: Affected (git)
    • ≥ b7cccd397f310739fb85383033e95580f99927e0, < d62007edf01f5c11f75d0f4b1e538fc52a5b1982: Affected (git)

    No fix published

  • linux

    Versions
    • 5.13: Affected
    • ≥ 0, < 5.13: Not affected (semver)
    • ≥ 5.15.33, ≤ 5.15.*: Not affected (semver)
    • ≥ 5.16.19, ≤ 5.16.*: Not affected (semver)
    • ≥ 5.17.2, ≤ 5.17.*: Not affected (semver)
    • ≥ 5.18: Not affected (original_commit_for_fix)

    No fix published

  • linux Debian:12

    Affected ranges
    • ECOSYSTEM: < 5.17.3-1

    Update to 5.17.3-1

  • linux Debian:13

    Affected ranges
    • ECOSYSTEM: < 5.17.3-1

    Update to 5.17.3-1

  • linux Debian:14

    Affected ranges
    • ECOSYSTEM: < 5.17.3-1

    Update to 5.17.3-1

  • linux-hwe-edge Ubuntu:16.04:LTS

    Versions
    • 4.8.0-28.30~16.04.1
    • 4.8.0-30.32~16.04.1
    • 4.8.0-32.34~16.04.1
    • 4.8.0-34.36~16.04.1
    • 4.10.0-14.16~16.04.1
    • 4.10.0-19.21~16.04.1
    • 4.10.0-20.22~16.04.1
    • 4.10.0-21.23~16.04.1
    • 4.10.0-22.24~16.04.1
    • 4.10.0-24.28~16.04.1
    • 4.10.0-26.30~16.04.1
    • 4.11.0-13.19~16.04.1
    • 4.11.0-14.20~16.04.1
    • 4.13.0-16.19~16.04.3
    • 4.13.0-17.20~16.04.1
    • 4.13.0-19.22~16.04.1
    • 4.13.0-21.24~16.04.1
    • 4.13.0-25.29~16.04.2
    • 4.15.0-13.14~16.04.1
    • 4.15.0-15.16~16.04.1
    • 4.15.0-20.21~16.04.1
    • 4.15.0-22.24~16.04.1
    • 4.15.0-23.25~16.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-aws-5.0 Ubuntu:18.04:LTS

    Versions
    • 5.0.0-1021.24~18.04.1
    • 5.0.0-1022.25~18.04.1
    • 5.0.0-1023.26~18.04.1
    • 5.0.0-1024.27~18.04.1
    • 5.0.0-1025.28
    • 5.0.0-1027.30
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-aws-5.3 Ubuntu:18.04:LTS

    Versions
    • 5.3.0-1016.17~18.04.1
    • 5.3.0-1017.18~18.04.1
    • 5.3.0-1019.21~18.04.1
    • 5.3.0-1023.25~18.04.1
    • 5.3.0-1028.30~18.04.1
    • 5.3.0-1030.32~18.04.1
    • 5.3.0-1032.34~18.04.2
    • 5.3.0-1033.35
    • 5.3.0-1034.36
    • 5.3.0-1035.37
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-azure Ubuntu:18.04:LTS

    Versions
    • 4.15.0-1002.2
    • 4.15.0-1003.3
    • 4.15.0-1004.4
    • 4.15.0-1008.8
    • 4.15.0-1009.9
    • 4.15.0-1012.12
    • 4.15.0-1013.13
    • 4.15.0-1014.14
    • 4.15.0-1018.18
    • 4.15.0-1019.19
    • 4.15.0-1021.21
    • 4.15.0-1022.23
    • 4.15.0-1023.24
    • 4.15.0-1025.26
    • 4.15.0-1028.29
    • 4.15.0-1030.31
    • 4.15.0-1031.32
    • 4.15.0-1032.33
    • 4.15.0-1035.36
    • 4.15.0-1036.38
    • 4.15.0-1037.39
    • 4.18.0-1011.11~18.04.1
    • 4.18.0-1013.13~18.04.1
    • 4.18.0-1014.14~18.04.1
    • 4.18.0-1018.18~18.04.1
    • 4.18.0-1019.19~18.04.1
    • 4.18.0-1020.20~18.04.1
    • 4.18.0-1023.24~18.04.1
    • 4.18.0-1024.25~18.04.1
    • 4.18.0-1025.27~18.04.1
    • 5.0.0-1014.14~18.04.1
    • 5.0.0-1016.17~18.04.1
    • 5.0.0-1018.19~18.04.1
    • 5.0.0-1020.21~18.04.1
    • 5.0.0-1022.23~18.04.1
    • 5.0.0-1023.24~18.04.1
    • 5.0.0-1025.27~18.04.1
    • 5.0.0-1027.29~18.04.1
    • 5.0.0-1028.30~18.04.1
    • 5.0.0-1029.31~18.04.1
    • 5.0.0-1031.33
    • 5.0.0-1032.34
    • 5.0.0-1035.37
    • 5.0.0-1036.38
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-azure-5.3 Ubuntu:18.04:LTS

    Versions
    • 5.3.0-1007.8~18.04.1
    • 5.3.0-1008.9~18.04.1
    • 5.3.0-1009.10~18.04.1
    • 5.3.0-1010.11~18.04.1
    • 5.3.0-1012.13~18.04.1
    • 5.3.0-1013.14~18.04.1
    • 5.3.0-1016.17~18.04.1
    • 5.3.0-1018.19~18.04.1
    • 5.3.0-1019.20~18.04.1
    • 5.3.0-1020.21~18.04.1
    • 5.3.0-1022.23~18.04.1
    • 5.3.0-1028.29~18.04.1
    • 5.3.0-1031.32~18.04.1
    • 5.3.0-1032.33~18.04.1
    • 5.3.0-1034.35~18.04.1
    • 5.3.0-1035.36
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-azure-edge Ubuntu:18.04:LTS

    Versions
    • 4.18.0-1006.6~18.04.1
    • 4.18.0-1007.7~18.04.1
    • 4.18.0-1008.8~18.04.1
    • 5.0.0-1012.12~18.04.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-gcp Ubuntu:18.04:LTS

    Versions
    • 4.15.0-1001.1
    • 4.15.0-1003.3
    • 4.15.0-1005.5
    • 4.15.0-1006.6
    • 4.15.0-1008.8
    • 4.15.0-1009.9
    • 4.15.0-1010.10
    • 4.15.0-1014.14
    • 4.15.0-1015.15
    • 4.15.0-1017.18
    • 4.15.0-1018.19
    • 4.15.0-1019.20
    • 4.15.0-1021.22
    • 4.15.0-1023.24
    • 4.15.0-1024.25
    • 4.15.0-1025.26
    • 4.15.0-1026.27
    • 4.15.0-1027.28
    • 4.15.0-1028.29
    • 4.15.0-1029.31
    • 4.15.0-1030.32
    • 4.15.0-1032.34
    • 4.15.0-1033.35
    • 4.15.0-1034.36
    • 4.15.0-1036.38
    • 4.15.0-1037.39
    • 4.15.0-1040.42
    • 4.15.0-1042.45
    • 4.15.0-1044.70
    • 5.0.0-1020.20~18.04.1
    • 5.0.0-1021.21~18.04.1
    • 5.0.0-1025.26~18.04.1
    • 5.0.0-1026.27~18.04.1
    • 5.0.0-1028.29~18.04.1
    • 5.0.0-1029.30~18.04.1
    • 5.0.0-1031.32
    • 5.0.0-1033.34
    • 5.0.0-1034.35
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-gcp-5.3 Ubuntu:18.04:LTS

    Versions
    • 5.3.0-1008.9~18.04.1
    • 5.3.0-1009.10~18.04.1
    • 5.3.0-1010.11~18.04.1
    • 5.3.0-1012.13~18.04.1
    • 5.3.0-1014.15~18.04.1
    • 5.3.0-1016.17~18.04.1
    • 5.3.0-1017.18~18.04.1
    • 5.3.0-1018.19~18.04.1
    • 5.3.0-1020.22~18.04.1
    • 5.3.0-1026.28~18.04.1
    • 5.3.0-1029.31~18.04.1
    • 5.3.0-1030.32~18.04.1
    • 5.3.0-1032.34~18.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-gke-4.15 Ubuntu:18.04:LTS

    Versions
    • 4.15.0-1030.32
    • 4.15.0-1032.34
    • 4.15.0-1033.35
    • 4.15.0-1034.36
    • 4.15.0-1036.38
    • 4.15.0-1037.39
    • 4.15.0-1040.42
    • 4.15.0-1041.43
    • 4.15.0-1042.44
    • 4.15.0-1044.46
    • 4.15.0-1045.48
    • 4.15.0-1046.49
    • 4.15.0-1048.51
    • 4.15.0-1049.52
    • 4.15.0-1050.53
    • 4.15.0-1052.55
    • 4.15.0-1055.58
    • 4.15.0-1057.60
    • 4.15.0-1058.61
    • 4.15.0-1059.62
    • 4.15.0-1063.66
    • 4.15.0-1064.67
    • 4.15.0-1066.69
    • 4.15.0-1067.70
    • 4.15.0-1069.72
    • 4.15.0-1070.73
    • 4.15.0-1072.76
    • 4.15.0-1073.78
    • 4.15.0-1074.79
    • 4.15.0-1076.81
    • 4.15.0-1077.82
    • 4.15.0-1078.83
    • 4.15.0-1079.84
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-gke-5.4 Ubuntu:18.04:LTS

    Versions
    • 5.4.0-1025.25~18.04.1
    • 5.4.0-1027.28~18.04.1
    • 5.4.0-1029.31~18.04.1
    • 5.4.0-1030.32~18.04.1
    • 5.4.0-1032.34~18.04.1
    • 5.4.0-1033.35~18.04.1
    • 5.4.0-1035.37~18.04.1
    • 5.4.0-1036.38~18.04.1
    • 5.4.0-1037.39~18.04.1
    • 5.4.0-1039.41~18.04.1
    • 5.4.0-1040.42~18.04.1
    • 5.4.0-1042.44~18.04.1
    • 5.4.0-1043.45~18.04.1
    • 5.4.0-1044.46~18.04.1
    • 5.4.0-1046.48~18.04.1
    • 5.4.0-1049.52~18.04.1
    • 5.4.0-1051.54~18.04.1
    • 5.4.0-1052.55~18.04.1
    • 5.4.0-1053.56~18.04.1
    • 5.4.0-1054.57~18.04.1
    • 5.4.0-1055.58~18.04.1
    • 5.4.0-1056.59~18.04.1
    • 5.4.0-1057.60~18.04.1
    • 5.4.0-1059.62~18.04.1
    • 5.4.0-1061.64~18.04.1
    • 5.4.0-1062.65~18.04.1
    • 5.4.0-1063.66~18.04.1
    • 5.4.0-1065.68~18.04.1
    • 5.4.0-1066.69~18.04.1
    • 5.4.0-1067.70~18.04.1
    • 5.4.0-1068.71~18.04.1
    • 5.4.0-1071.76~18.04.3
    • 5.4.0-1072.77~18.04.1
    • 5.4.0-1074.79~18.04.1
    • 5.4.0-1076.82~18.04.1
    • 5.4.0-1078.84~18.04.1
    • 5.4.0-1080.86~18.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-gkeop-5.4 Ubuntu:18.04:LTS

    Versions
    • 5.4.0-1001.1
    • 5.4.0-1003.3
    • 5.4.0-1004.5
    • 5.4.0-1005.6
    • 5.4.0-1007.8~18.04.1
    • 5.4.0-1008.9~18.04.1
    • 5.4.0-1009.10~18.04.1
    • 5.4.0-1010.11~18.04.1
    • 5.4.0-1011.12~18.04.2
    • 5.4.0-1012.13~18.04.1
    • 5.4.0-1013.14~18.04.1
    • 5.4.0-1014.15~18.04.1
    • 5.4.0-1015.16~18.04.1
    • 5.4.0-1016.17~18.04.1
    • 5.4.0-1018.19~18.04.1
    • 5.4.0-1021.22~18.04.1
    • 5.4.0-1022.23~18.04.1
    • 5.4.0-1023.24~18.04.1
    • 5.4.0-1024.25~18.04.1
    • 5.4.0-1025.26~18.04.1
    • 5.4.0-1026.27~18.04.1
    • 5.4.0-1027.28~18.04.1
    • 5.4.0-1029.30~18.04.2
    • 5.4.0-1031.32~18.04.1
    • 5.4.0-1032.33~18.04.1
    • 5.4.0-1033.34~18.04.1
    • 5.4.0-1034.35~18.04.1
    • 5.4.0-1036.37~18.04.1
    • 5.4.0-1037.38~18.04.1
    • 5.4.0-1038.39~18.04.1
    • 5.4.0-1039.40~18.04.1
    • 5.4.0-1040.41~18.04.1
    • 5.4.0-1043.44~18.04.1
    • 5.4.0-1046.48~18.04.1
    • 5.4.0-1048.51~18.04.1
    • 5.4.0-1049.52~18.04.1
    • 5.4.0-1051.54~18.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-hwe Ubuntu:18.04:LTS

    Versions
    • 4.18.0-13.14~18.04.1
    • 4.18.0-14.15~18.04.1
    • 4.18.0-15.16~18.04.1
    • 4.18.0-16.17~18.04.1
    • 4.18.0-17.18~18.04.1
    • 4.18.0-18.19~18.04.1
    • 4.18.0-20.21~18.04.1
    • 4.18.0-21.22~18.04.1
    • 4.18.0-22.23~18.04.1
    • 4.18.0-24.25~18.04.1
    • 4.18.0-25.26~18.04.1
    • 5.0.0-23.24~18.04.1
    • 5.0.0-25.26~18.04.1
    • 5.0.0-27.28~18.04.1
    • 5.0.0-29.31~18.04.1
    • 5.0.0-31.33~18.04.1
    • 5.0.0-32.34~18.04.2
    • 5.0.0-35.38~18.04.1
    • 5.0.0-36.39~18.04.1
    • 5.0.0-37.40~18.04.1
    • 5.3.0-26.28~18.04.1
    • 5.3.0-28.30~18.04.1
    • 5.3.0-40.32~18.04.1
    • 5.3.0-42.34~18.04.1
    • 5.3.0-45.37~18.04.1
    • 5.3.0-46.38~18.04.1
    • 5.3.0-51.44~18.04.2
    • 5.3.0-53.47~18.04.1
    • 5.3.0-59.53~18.04.1
    • 5.3.0-61.55~18.04.1
    • 5.3.0-62.56~18.04.1
    • 5.3.0-64.58~18.04.1
    • 5.3.0-65.59
    • 5.3.0-66.60
    • 5.3.0-67.61
    • 5.3.0-68.63
    • 5.3.0-69.65
    • 5.3.0-70.66
    • 5.3.0-72.68
    • 5.3.0-73.69
    • 5.3.0-74.70
    • 5.3.0-75.71
    • 5.3.0-76.72
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-hwe-edge Ubuntu:18.04:LTS

    Versions
    • 5.0.0-15.16~18.04.1
    • 5.0.0-16.17~18.04.1
    • 5.0.0-17.18~18.04.1
    • 5.0.0-19.20~18.04.1
    • 5.0.0-20.21~18.04.1
    • 5.3.0-19.20~18.04.2
    • 5.3.0-22.24~18.04.1
    • 5.3.0-23.25~18.04.1
    • 5.3.0-23.25~18.04.2
    • 5.3.0-24.26~18.04.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-oem Ubuntu:18.04:LTS

    Versions
    • 4.15.0-1002.3
    • 4.15.0-1004.5
    • 4.15.0-1006.9
    • 4.15.0-1008.11
    • 4.15.0-1009.12
    • 4.15.0-1012.15
    • 4.15.0-1013.16
    • 4.15.0-1015.18
    • 4.15.0-1017.20
    • 4.15.0-1018.21
    • 4.15.0-1021.24
    • 4.15.0-1024.29
    • 4.15.0-1026.31
    • 4.15.0-1028.33
    • 4.15.0-1030.35
    • 4.15.0-1033.38
    • 4.15.0-1034.39
    • 4.15.0-1035.40
    • 4.15.0-1036.41
    • 4.15.0-1038.43
    • 4.15.0-1039.44
    • 4.15.0-1043.48
    • 4.15.0-1045.50
    • 4.15.0-1050.57
    • 4.15.0-1056.65
    • 4.15.0-1057.66
    • 4.15.0-1059.68
    • 4.15.0-1063.72
    • 4.15.0-1064.73
    • 4.15.0-1065.75
    • 4.15.0-1066.76
    • 4.15.0-1067.77
    • 4.15.0-1069.79
    • 4.15.0-1073.83
    • 4.15.0-1076.86
    • 4.15.0-1079.89
    • 4.15.0-1080.90
    • 4.15.0-1081.91
    • 4.15.0-1087.97
    • 4.15.0-1090.100
    • 4.15.0-1091.101
    • 4.15.0-1093.103
    • 4.15.0-1094.104
    • 4.15.0-1096.106
    • 4.15.0-1097.107
    • 4.15.0-1099.109
    • 4.15.0-1100.110
    • 4.15.0-1101.112
    • 4.15.0-1102.113
    • 4.15.0-1103.114
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-oracle-5.0 Ubuntu:18.04:LTS

    Versions
    • 5.0.0-1007.12~18.04.1
    • 5.0.0-1008.13~18.04.1
    • 5.0.0-1009.14~18.04.1
    • 5.0.0-1010.15~18.04.1
    • 5.0.0-1011.16
    • 5.0.0-1013.18
    • 5.0.0-1014.19
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-oracle-5.3 Ubuntu:18.04:LTS

    Versions
    • 5.3.0-1011.12~18.04.1
    • 5.3.0-1013.14~18.04.1
    • 5.3.0-1014.15~18.04.1
    • 5.3.0-1016.18~18.04.1
    • 5.3.0-1018.20~18.04.1
    • 5.3.0-1024.26~18.04.1
    • 5.3.0-1027.29~18.04.1
    • 5.3.0-1028.30~18.04.1
    • 5.3.0-1030.32~18.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • linux-azure-5.15 Ubuntu:20.04:LTS

    Versions
    • 5.15.0-1007.8~20.04.1
    Affected ranges
    • ECOSYSTEM: < 5.15.0-1008.9~20.04.1

    Update to 5.15.0-1008.9~20.04.1

  • linux-hwe-5.15 Ubuntu:20.04:LTS

    Versions
    • 5.15.0-33.34~20.04.1
    Affected ranges
    • ECOSYSTEM: < 5.15.0-41.44~20.04.1

    Update to 5.15.0-41.44~20.04.1

  • linux-intel-iotg-5.15 Ubuntu:20.04:LTS

    Versions
    • 5.15.0-1003.5~20.04.1
    Affected ranges
    • ECOSYSTEM: < 5.15.0-1008.11~20.04.1

    Update to 5.15.0-1008.11~20.04.1

Original sources

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