Cloudanix VulnDB

CVE-2024-56628

None

CVSS

—

EPSS

0.2%

Published

Dec 27, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A flaw in how certain systems handle large memory pages can cause crashes when programs finish using memory, requiring an update to restore reliable operation.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Incorrect huge_pte_clear implementation on LoongArch allows zero-valued entries instead of invalid_pte_table or _PAGE_HUGE, causing pmd_none to return false and free_pte_range to be invoked on invalid PMDs during free_pgd_range and tlb_finish_mmu, resulting in bad page state and non-zero pgtables_bytes.

Why it matters to the business

Kernel crashes and memory management failures on LoongArch systems during process exit or memory self-tests reduce system stability and availability, with the issue present in older qemu packages on Ubuntu 14.04 LTS.

How an attack unfolds

An attacker runs workloads that create and tear down memory mappings with huge pages (such as userfaultfd tests or exit_mmap paths); the kernel's free_pmd_range then misinterprets invalid entries, triggers free_unref_folios on reserved pages, and panics with bad page state.

How to fix it

Upgrade affected qemu packages on Ubuntu 14.04 LTS to version 2.0.0+dfsg-2ubuntu1.26 or later; apply the corresponding Linux kernel patch that adds architecture-specific huge_pte_clear using invalid_pte_table.

How to confirm the fix worked

Confirm package version is at or above the fixed release, re-run mm selftests including run_vmtests.sh, and verify absence of bad page state and non-zero pgtables_bytes errors on process exit.

Typical attack path

  1. Trigger process exit or munmap involving huge PMDs on LoongArch
  2. pmd_none_or_clear_bad returns false due to zero huge_pte
  3. free_pte_range called on invalid table
  4. folios_put_refs and free_unref_folios operate on reserved PFN 0
  5. Kernel logs BUG: Bad page state and non-zero pgtables_bytes then panics

How to detect it

Search kernel logs and dmesg for 'BUG: Bad page state', 'PAGE_FLAGS_CHECK_AT_FREE', 'non-zero pgtables_bytes on freeing mm', and call traces containing free_pmd_range, tlb_finish_mmu, and exit_mmap; correlate with processes using userfaultfd or huge pages on LoongArch.

  • BUG: Bad page state in process
  • non-zero pgtables_bytes on freeing mm
  • page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  • free_pmd_range
  • tlb_finish_mmu

What your security team should do

  • Apply the listed qemu package update immediately on all LoongArch Ubuntu 14.04 systems
  • Monitor kernel logs for 'Bad page state' and 'non-zero pgtables_bytes' messages
  • Prioritize testing of memory-mapping heavy workloads after patching

The record

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Add architecture specific huge_pte_clear() When executing mm selftests run_vmtests.sh, there is such an error: BUG: Bad page state in process uffd-unit-tests pfn:00000 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0 flags: 0xffff0000002000(reserved|node=0|zone=0|lastcpupid=0xffff) raw: 00ffff0000002000 ffffbf0000000008 ffffbf0000000008 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Modules linked in: snd_seq_dummy snd_seq snd_seq_device rfkill vfat fat virtio_balloon efi_pstore virtio_net pstore net_failover failover fuse nfnetlink virtio_scsi virtio_gpu virtio_dma_buf dm_multipath efivarfs CPU: 2 UID: 0 PID: 1913 Comm: uffd-unit-tests Not tainted 6.12.0 #184 Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 Stack : 900000047c8ac000 0000000000000000 9000000000223a7c 900000047c8ac000 900000047c8af690 900000047c8af698 0000000000000000 900000047c8af7d8 900000047c8af7d0 900000047c8af7d0 900000047c8af5b0 0000000000000001 0000000000000001 900000047c8af698 10b3c7d53da40d26 0000010000000000 0000000000000022 0000000fffffffff fffffffffe000000 ffff800000000000 000000000000002f 0000800000000000 000000017a6d4000 90000000028f8940 0000000000000000 0000000000000000 90000000025aa5e0 9000000002905000 0000000000000000 90000000028f8940 ffff800000000000 0000000000000000 0000000000000000 0000000000000000 9000000000223a94 000000012001839c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d ... Call Trace: [<9000000000223a94>] show_stack+0x5c/0x180 [<9000000001c3fd64>] dump_stack_lvl+0x6c/0xa0 [<900000000056aa08>] bad_page+0x1a0/0x1f0 [<9000000000574978>] free_unref_folios+0xbf0/0xd20 [<90000000004e65cc>] folios_put_refs+0x1a4/0x2b8 [<9000000000599a0c>] free_pages_and_swap_cache+0x164/0x260 [<9000000000547698>] tlb_batch_pages_flush+0xa8/0x1c0 [<9000000000547f30>] tlb_finish_mmu+0xa8/0x218 [<9000000000543cb8>] exit_mmap+0x1a0/0x360 [<9000000000247658>] __mmput+0x78/0x200 [<900000000025583c>] do_exit+0x43c/0xde8 [<9000000000256490>] do_group_exit+0x68/0x110 [<9000000000256554>] sys_exit_group+0x1c/0x20 [<9000000001c413b4>] do_syscall+0x94/0x130 [<90000000002216d8>] handle_syscall+0xb8/0x158 Disabling lock debugging due to kernel taint BUG: non-zero pgtables_bytes on freeing mm: -16384 On LoongArch system, invalid huge pte entry should be invalid_pte_table or a single _PAGE_HUGE bit rather than a zero value. And it should be the same with invalid pmd entry, since pmd_none() is called by function free_pgd_range() and pmd_none() return 0 by huge_pte_clear(). So single _PAGE_HUGE bit is also treated as a valid pte table and free_pte_range() will be called in free_pmd_range(). free_pmd_range() pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); if (pmd_none_or_clear_bad(pmd)) continue; free_pte_range(tlb, pmd, addr); } while (pmd++, addr = next, addr != end); Here invalid_pte_table is used for both invalid huge pte entry and pmd entry.

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux-6.1 0 6.1.128-1~deb11u1
Debian:11 linux-6.1 0 6.1.6.1.128-1~deb11u1
Debian:12 linux 0 6.1.123-1
Debian:13 linux 0 6.12.5-1
Linux Kernel 5.19.0 6.1.120
Mageia:9 dwarves 0 1.29-1.mga9
Mageia:9 kernel 0 6.6.74-1.mga9
Mageia:9 kernel-linus 0 6.6.74-1.mga9
Mageia:9 kmod-virtualbox 0 7.0.24-64.mga9
Mageia:9 kmod-xtables-addons 0 3.24-70.mga9
Ubuntu:14.04:LTS linux 0 3.11.0-12.19
Ubuntu:14.04:LTS linux-aws 0 4.4.0-1002.2
Ubuntu:14.04:LTS linux-azure 0 4.15.0-1023.24~14.04.1
Ubuntu:14.04:LTS linux-lts-xenial 0 4.4.0-13.29~14.04.1
Ubuntu:16.04:LTS linux 0 4.4.0-2.16
Ubuntu:16.04:LTS linux-aws 0 4.4.0-1001.10
Ubuntu:16.04:LTS linux-aws-hwe 0 4.15.0-1030.31~16.04.1
Ubuntu:16.04:LTS linux-azure 0 4.11.0-1009.9
Ubuntu:16.04:LTS linux-gcp 0 4.10.0-1004.4
Ubuntu:16.04:LTS linux-hwe 0 4.8.0-39.42~16.04.1
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:16.04:LTS linux-kvm 0 4.4.0-1004.9
Ubuntu:16.04:LTS linux-oracle 0 4.15.0-1007.9~16.04.1
Ubuntu:18.04:LTS linux 0 4.13.0-16.19
Ubuntu:18.04:LTS linux-aws 0 4.15.0-1001.1
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-aws-5.4 0 5.4.0-1018.18~18.04.1
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-4.15 0 4.15.0-1082.92
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-5.4 0 5.4.0-1020.20~18.04.1
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-4.15 0 4.15.0-1071.81
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.4 0 5.4.0-1019.19~18.04.2
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-5.4 0 5.4.0-37.41~18.04.1
Ubuntu:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-ibm-5.4 0 5.4.0-1010.11~18.04.2
Ubuntu:18.04:LTS linux-kvm 0 4.15.0-1002.2
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle 0 4.15.0-1007.9
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.4 0 5.4.0-1019.19~18.04.1
Ubuntu:18.04:LTS linux-raspi-5.4 0 5.4.0-1013.13~18.04.1
Ubuntu:20.04:LTS linux 0 5.4.0-9.12
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 5.15.0-1014.18~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1006.6
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 5.15.0-1007.8~20.04.1
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 No fix
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1007.10
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 5.15.0-1006.9~20.04.1
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 No fix
Ubuntu:20.04:LTS linux-gkeop-5.15 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1003.4
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1033.36~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1003.5~20.04.1
Ubuntu:20.04:LTS linux-iot 0 5.4.0-1001.3
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1004.4
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 5.15.0-1007.9~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1007.7
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 5.15.0-1015.17~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 5.4.0-1020.24
Ubuntu:22.04:LTS linux 0 5.13.0-19.19
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.13.0-1005.6
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 No fix
Ubuntu:22.04:LTS linux-azure 0 5.13.0-1006.7
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 No fix
Ubuntu:22.04:LTS linux-azure-fde 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 5.13.0-1005.6
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 No fix
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1001.2
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 5.15.0-1021.26
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1004.6
Ubuntu:22.04:LTS linux-kvm 0 5.13.0-1004.4
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-22.22
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1005.5
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 No fix
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix
Ubuntu:22.04:LTS linux-oem-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle 0 5.13.0-1008.10
Ubuntu:22.04:LTS linux-oracle-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.8 0 No fix
Ubuntu:22.04:LTS linux-raspi 0 5.13.0-1008.9
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 No fix
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 No fix
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 5.15.0-1022.26
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 5.15.0-1011.13
Ubuntu:24.04:LTS linux 0 No fix
Ubuntu:24.04:LTS linux-aws 0 No fix
Ubuntu:24.04:LTS linux-azure 0 No fix
Ubuntu:24.04:LTS linux-azure-fde 0 No fix
Ubuntu:24.04:LTS linux-gcp 0 No fix
Ubuntu:24.04:LTS linux-gke 0 No fix
Ubuntu:24.04:LTS linux-gkeop 0 No fix
Ubuntu:24.04:LTS linux-hwe-6.11 0 No fix
Ubuntu:24.04:LTS linux-ibm 0 No fix
Ubuntu:24.04:LTS linux-intel 0 No fix
Ubuntu:24.04:LTS linux-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-lowlatency-hwe-6.11 0 No fix
Ubuntu:24.04:LTS linux-nvidia 0 No fix
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-oem-6.11 0 No fix
Ubuntu:24.04:LTS linux-oem-6.8 0 No fix
Ubuntu:24.04:LTS linux-oracle 0 No fix
Ubuntu:24.04:LTS linux-raspi 0 No fix
Ubuntu:24.04:LTS linux-raspi-realtime 0 No fix
Ubuntu:24.04:LTS linux-realtime 0 No fix
Ubuntu:24.04:LTS linux-riscv 0 No fix
Ubuntu:24.10 linux 0 No fix
Ubuntu:24.10 linux-aws 0 No fix
Ubuntu:24.10 linux-azure 0 No fix
Ubuntu:24.10 linux-gcp 0 No fix
Ubuntu:24.10 linux-lowlatency 0 No fix
Ubuntu:24.10 linux-oracle 0 No fix
Ubuntu:24.10 linux-raspi 0 No fix
Ubuntu:24.10 linux-realtime 0 No fix
Ubuntu:24.10 linux-riscv 0 No fix
Ubuntu:Pro:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-gkeop-5.4 0 No fix

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