CVE-2025-38493

Medium

In the Linux kernel, the following vulnerability has been resolved: tracing/osnoise: Fix crash in timerlat_dump_stack() We have observed kernel panics when using timerlat with stack saving, with the following dmesg output: memcpy: detected buffer overflow: 88 byte write of buffer size 0 WARNING: CPU: 2 PID: 8153 at lib/string_helpers.c:1032 __fortify_report+0x55/0xa0 CPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy) Call Trace: <TASK> ? trace_buffer_lock_reserve+0x2a/0x60 __fortify_panic+0xd/0xf __timerlat_dump_stack.cold+0xd/0xd timerlat_dump_stack.part.0+0x47/0x80 timerlat_fd_read+0x36d/0x390 vfs_read+0xe2/0x390 ? syscall_exit_to_user_mode+0x1d5/0x210 ksys_read+0x73/0xe0 do_syscall_64+0x7b/0x160 ? exc_page_fault+0x7e/0x1a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e __timerlat_dump_stack() constructs the ftrace stack entry like this: struct stack_entry *entry; ... memcpy(&entry->caller, fstack->calls, size); entry->size = fstack->nr_entries; Since commit e7186af7fb26 ("tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure"), struct stack_entry marks its caller field with __counted_by(size). At the time of the memcpy, entry->size contains garbage from the ringbuffer, which under some circumstances is zero, triggering a kernel panic by buffer overflow. Populate the size field before the memcpy so that the out-of-bounds check knows the correct size. This is analogous to __ftrace_trace_stack().

Package Linux Kernel
Published 2025-07-28
Last modified 2025-11-19
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-674

CVE-2025-38493 is a Uncontrolled Recursion vulnerability

What is Uncontrolled Recursion?

The product does not properly control the amount of recursion which triggers resource consumption. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.6 and later are affected. Fixed in 6.6.100, 6.12.40, 6.15.8, 6.16 and their respective stable series.

Affected from
≥ 6.6
Fixed in
✓ 6.6.100 6.6.x ✓ 6.12.40 6.12.x ✓ 6.15.8 6.15.x ✓ 6.16

References

The following references provide additional information about CVE-2025-38493 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-38493?

    CVE-2025-38493 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Uncontrolled Recursion flaw (CWE-674) . It affects Linux kernel versions from 6.6 onward and has been patched in 6.6.100, 6.12.40, 6.15.8 and others. CVE-2025-38493 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-38493?

    CVE-2025-38493 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-38493?

    Yes — CVE-2025-38493 has been patched. Fixed versions include 6.6.100, 6.12.40, 6.15.8 and others. If you are running Linux kernel 6.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-38493 actively exploited?

    No — CVE-2025-38493 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Uncontrolled Recursion (CWE-674)?

    The product does not properly control the amount of recursion which triggers resource consumption. View CWE-674 on MITRE CWE →

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