In the Linux kernel, the following vulnerability has been resolved:

riscv: process: Fix kernel gp leakage

childregs represents the registers which are active for the new thread
in user context. For a kernel thread, childregs->gp is never used since
the kernel gp is not touched by switch_to. For a user mode helper, the
gp value can be observed in user space after execve or possibly by other
means.

[From the email thread]

The /* Kernel thread */ comment is somewhat inaccurate in that it is also used
for user_mode_helper threads, which exec a user process, e.g. /sbin/init or
when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have
PF_KTHREAD set and are valid targets for ptrace etc. even before they exec.

childregs is the *user* context during syscall execution and it is observable
from userspace in at least five ways:

1. kernel_execve does not currently clear integer registers, so the starting
register state for PID 1 and other user processes started by the kernel has
sp = user stack, gp = kernel __global_pointer$, all other integer registers
zeroed by the memset in the patch comment.

This is a bug in its own right, but I'm unwilling to bet that it is the only
way to exploit the issue addressed by this patch.

2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread
before it execs, but ptrace requires SIGSTOP to be delivered which can only
happen at user/kernel boundaries.

3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for
user_mode_helpers before the exec completes, but gp is not one of the
registers it returns.

4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel
addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses
are also exposed via PERF_SAMPLE_REGS_USER which is permitted under
LOCKDOWN_PERF. I have not attempted to write exploit code.

5. Much of the tracing infrastructure allows access to user registers. I have
not attempted to determine which forms of tracing allow access to user
registers without already allowing access to kernel registers.

Project Subscriptions

Vendors Products
Debian Linux Subscribe
Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-3842-1 linux-5.10 security update
Ubuntu USN Ubuntu USN USN-6893-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6893-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6893-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-3 Linux kernel kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6917-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6918-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6919-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6927-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7019-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 22 Jan 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}


Fri, 22 Nov 2024 12:00:00 +0000

Type Values Removed Values Added
References

Tue, 05 Nov 2024 10:45:00 +0000

Type Values Removed Values Added
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:07:18.449Z

Reserved: 2024-05-17T13:50:33.108Z

Link: CVE-2024-35871

cve-icon Vulnrichment

Updated: 2024-06-17T17:38:52.800Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-19T09:15:08.507

Modified: 2026-01-22T20:21:18.273

Link: CVE-2024-35871

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-19T00:00:00Z

Links: CVE-2024-35871 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-12T22:31:25Z

Weaknesses