Cloudanix VulnDB

CVE-2024-26850

None

CVSS

—

EPSS

0.2%

Published

Apr 17, 2024

CISA due date

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Cloudanix analysis

Monitor only SSVC: Track

A bug in the Linux kernel's memory testing code could cause crashes on certain hardware during debugging.

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

What it actually does

The debug VM pagetable test code fails to mark PUD entries as device-map entries, causing architecture-specific debug checks on powerpc to trigger warnings or kernel BUGs when CONFIG_DEBUG_VM is enabled.

Why it matters to the business

Systems using debug kernels on affected architectures may experience boot failures or crashes during initialization, impacting development, testing, and debugging workflows.

How an attack unfolds

An attacker would need to trigger the debug_vm_pgtable initialization path, but this is primarily a kernel developer debug feature and not reachable in production configurations.

How to fix it

Update the Linux kernel to a version incorporating commit d2a9510c0e39d06f5544075c13040407bdbf2803 or later.

How to confirm the fix worked

Verify the presence of the fix commit in the kernel source and ensure no warnings or BUGs occur during debug_vm_pgtable execution on powerpc.

Typical attack path

  1. Enable CONFIG_DEBUG_VM
  2. Run on powerpc architecture
  3. Trigger pud_advanced_tests during init

How to detect it

Monitor kernel logs for warnings or BUGs related to radix__pud_hugepage_update or pudp_huge_get_and_clear_full during system initialization.

What your security team should do

  • Apply the kernel update containing the fix
  • Disable CONFIG_DEBUG_VM in production if not needed

The record

In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: fix BUG_ON with pud advanced test Architectures like powerpc add debug checks to ensure we find only devmap PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM. This patch marks the ptes used for PUD advanced test devmap pte entries so that we don't hit on debug checks on architecture like ppc64 as below. WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138 .... NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138 LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60 Call Trace: [c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable) [c000000004a2f980] [000d34c100000000] 0xd34c100000000 [c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388 Also kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202! .... NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174 LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 Call Trace: [c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable) [c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

Affected packages

Ecosystem Package Introduced Fixed
Debian:13 linux 0 6.7.9-1
Linux Kernel 6.6.0 6.6.21
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-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-5.4 0 5.4.0-1018.18~18.04.1
Ubuntu:18.04:LTS linux-azure-4.15 0 4.15.0-1082.92
Ubuntu:18.04:LTS linux-azure-5.4 0 5.4.0-1020.20~18.04.1
Ubuntu:18.04:LTS linux-gcp-4.15 0 4.15.0-1071.81
Ubuntu:18.04:LTS linux-gcp-5.4 0 5.4.0-1019.19~18.04.2
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 5.0.0-15.16~18.04.1
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-oracle 0 4.15.0-1007.9
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:22.04:LTS linux-aws-6.8 0 6.8.0-1009.9~22.04.2
Ubuntu:22.04:LTS linux-azure-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1010.11~22.04.1
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-38.38~22.04.1
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-lowlatency-hwe-6.8 0 6.8.0-38.38.1~22.04.2
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-oracle-6.8 0 6.8.0-1006.6~22.04.3
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 6.8.0-38.38.1~22.04.1
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 5.15.0-1011.13
Ubuntu:24.04:LTS linux-gke 0 6.8.0-1003.5
Ubuntu:24.04:LTS linux-gkeop 0 6.8.0-1001.3
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 6.8.0-1009.9.1
Ubuntu:24.04:LTS linux-oem-6.11 0 6.11.0-1007.7
Ubuntu:24.04:LTS linux-oem-6.8 0 6.8.0-1003.3
Ubuntu:24.04:LTS linux-raspi-realtime 0 No fix
Ubuntu:24.04:LTS linux-realtime 0 6.8.0-1008.19
Ubuntu:24.10 linux-realtime 0 6.11.0-1001.1
Ubuntu:Pro:24.04:LTS:Realtime:Kernel linux-raspi-realtime 0 6.8.0-2002.2
Ubuntu:Pro:FIPS-preview:22.04:LTS linux-aws-fips 0 5.15.0-1051.56+fips1
Ubuntu:Pro:FIPS-preview:22.04:LTS linux-azure-fips 0 5.15.0-1053.61+fips1
Ubuntu:Pro:FIPS-preview:22.04:LTS linux-fips 0 5.15.0-73.80+fips1
Ubuntu:Pro:FIPS-preview:22.04:LTS linux-gcp-fips 0 5.15.0-1048.56+fips1
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-aws-fips 0 4.15.0-2000.4
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-azure-fips 0 4.15.0-1002.2
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-gcp-fips 0 4.15.0-2013.14
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-aws-fips 0 5.4.0-1021.21+fips2
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-azure-fips 0 5.4.0-1022.22+fips1
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-gcp-fips 0 5.4.0-1021.21+fips1
Ubuntu:Pro:FIPS-updates:22.04:LTS linux-aws-fips 0 5.15.0-1052.57+fips1
Ubuntu:Pro:FIPS-updates:22.04:LTS linux-azure-fips 0 5.15.0-1058.66+fips1
Ubuntu:Pro:FIPS-updates:22.04:LTS linux-fips 0 5.15.0-92.102+fips1
Ubuntu:Pro:FIPS-updates:22.04:LTS linux-gcp-fips 0 5.15.0-1048.56+fips1
Ubuntu:Pro:FIPS:18.04:LTS linux-aws-fips 0 4.15.0-2000.4
Ubuntu:Pro:FIPS:18.04:LTS linux-azure-fips 0 4.15.0-1002.2
Ubuntu:Pro:FIPS:18.04:LTS linux-gcp-fips 0 4.15.0-1001.1
Ubuntu:Pro:FIPS:20.04:LTS linux-aws-fips 0 5.4.0-1021.21+fips2
Ubuntu:Pro:FIPS:20.04:LTS linux-azure-fips 0 5.4.0-1022.22+fips1
Ubuntu:Pro:FIPS:20.04:LTS linux-gcp-fips 0 5.4.0-1021.21+fips1
Ubuntu:Pro:Realtime:24.04:LTS linux-raspi-realtime 0 6.8.0-2002.2

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