CVE-2024-57877
NoneCVSS
—
EPSS
0.2%
Published
Jan 11, 2025
CISA due date
—
Cloudanix analysis
A bug in the Linux kernel on certain processors could let attackers with special access peek at small pieces of hidden system memory.
- Exploitation
- Local Privilege
- Attacker needs
- Low Privilege
- Complexity
- Low
- Impact
- Data Exposure
- Component
- OS kernel
- Class
- Information Disclosure
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
A zero-length ptrace SETREGSET call for NT_ARM_POE on arm64 leaves an uninitialized kernel stack variable, causing up to 64 bits of kernel stack memory to be written into the target's por_el0 register.
Why it matters to the business
Attackers with ptrace access can leak sensitive kernel memory contents, potentially exposing credentials or other secrets and increasing risk of further compromise on affected systems.
How an attack unfolds
An attacker with the ability to call ptrace on a target process issues a zero-length SETREGSET for the NT_ARM_POE regset, causing the kernel to copy an uninitialized stack value into the process's thread state, which can later be read back via GETREGSET to obtain kernel stack data.
How to fix it
Update to a kernel version containing the fix that initializes the temporary variable before the regset copy. For the listed packages, upgrade chromium-browser to 58.0.3029.81-0ubuntu0.14.04.1172 or later.
How to confirm the fix worked
Verify the patch by testing that zero-length SETREGSET for NT_ARM_POE retains the previous POR_EL0 value instead of leaking stack data.
Typical attack path
- Identify a target process that can be ptraced
- Issue ptrace SETREGSET with NT_ARM_POE and length zero
- Read back the value using GETREGSET to obtain leaked kernel memory
How to detect it
Look for ptrace calls involving NT_ARM_POE regset in audit logs or strace outputs; no specific post-exploitation artifacts since it is a read-only leak.
What your security team should do
- Apply kernel updates containing the fix
- Restrict ptrace capabilities where possible using Yama LSM
- Monitor for unusual ptrace activity
The record
In the Linux kernel, the following vulnerability has been resolved: arm64: ptrace: fix partial SETREGSET for NT_ARM_POE Currently poe_set() doesn't initialize the temporary 'ctrl' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently an arbitrary value will be written back to target->thread.por_el0, potentially leaking up to 64 bits of memory from the kernel stack. The read is limited to a specific slot on the stack, and the issue does not provide a write mechanism. Fix this by initializing the temporary value before copying the regset from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG, NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing contents of POR_EL1 will be retained. Before this patch: | # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0xffff8000839c3d50 After this patch: | # ./poe-test | Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d | SETREGSET(nt=0x40f, len=8) wrote 8 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d | | Attempting to write NT_ARM_POE (zero length) | SETREGSET(nt=0x40f, len=0) wrote 0 bytes | | Attempting to read NT_ARM_POE::por_el0 | GETREGSET(nt=0x40f, len=8) read 8 bytes | Read NT_ARM_POE::por_el0 = 0x900d900d900d900d
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Debian:13 | linux | 0 | 6.12.5-1 |
| Linux | Kernel | 6.12.0 | 6.12.5 |
| 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 | 6.8.0-1009.9~22.04.2 |
| 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 | 6.8.0-1008.8~22.04.1 |
| 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 | 6.8.0-1010.11~22.04.1 |
| 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 | 6.8.0-38.38~22.04.1 |
| 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 | 6.8.0-38.38.1~22.04.2 |
| 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 | 6.8.0-1008.8~22.04.1 |
| 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 | 6.8.0-1006.6~22.04.3 |
| 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 | 6.8.0-38.38.1~22.04.1 |
| 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 | 6.5.0-9.9 |
| Ubuntu:24.04:LTS | linux-aws | 0 | 6.5.0-1008.8 |
| Ubuntu:24.04:LTS | linux-azure | 0 | 6.5.0-1007.7 |
| Ubuntu:24.04:LTS | linux-gcp | 0 | 6.5.0-1007.7 |
| 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-ibm | 0 | 6.5.0-1009.9 |
| Ubuntu:24.04:LTS | linux-lowlatency | 0 | 6.5.0-9.9.1 |
| Ubuntu:24.04:LTS | linux-nvidia | 0 | 6.8.0-1007.7 |
| 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-oracle | 0 | 6.5.0-1010.10 |
| Ubuntu:24.04:LTS | linux-raspi | 0 | 6.5.0-1005.7 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | 0 | No fix |
| Ubuntu:24.04:LTS | linux-raspi-realtime | 0 | 6.7.0-2001.1 |
| Ubuntu:24.04:LTS | linux-realtime | 0 | 6.8.0-1008.19 |
| Ubuntu:24.04:LTS | linux-riscv | 0 | 6.5.0-9.9.1 |
| Ubuntu:24.10 | linux | 0 | 6.8.0-31.31 |
| Ubuntu:24.10 | linux-aws | 0 | 6.8.0-1008.8 |
| Ubuntu:24.10 | linux-azure | 0 | 6.8.0-1007.7 |
| Ubuntu:24.10 | linux-gcp | 0 | 6.8.0-1007.7 |
| Ubuntu:24.10 | linux-lowlatency | 0 | 6.8.0-31.31.1 |
| Ubuntu:24.10 | linux-oracle | 0 | 6.8.0-1005.5 |
| Ubuntu:24.10 | linux-raspi | 0 | 6.8.0-1004.4 |
| Ubuntu:24.10 | linux-realtime | 0 | 6.11.0-1001.1 |
| Ubuntu:24.10 | linux-riscv | 0 | 6.8.0-31.31.1 |
| 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 |
| Ubuntu:Pro:18.04:LTS | linux-hwe | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-hwe-edge | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oem | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oracle-5.0 | 0 | No fix |
| Ubuntu:Pro:18.04:LTS | linux-oracle-5.3 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.11 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.13 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-aws-5.8 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-azure-5.11 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-azure-5.13 | 0 | No fix |
| Ubuntu:Pro:20.04:LTS | linux-azure-5.8 | 0 | No fix |
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