CVE-2025-39877

HIGH EPSS 3.8%
Published Sep 23, 20259mo ago · Modified Jun 17, 20261w ago
7.8 CVSS 3.1
High
Find Similar
Published Sep 23, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: fix use-after-free in state_show() state_show() reads kdamond->damon_ctx without holding damon_sysfs_lock. This allows a use-after-free race: CPU 0 CPU 1 ----- ----- state_show() damon_sysfs_turn_damon_on() ctx = kdamond->damon_ctx; mutex_lock(&damon_sysfs_lock); damon_destroy_ctx(kdamond->damon_ctx); kdamond->damon_ctx = NULL; mutex_unlock(&damon_sysfs_lock); damon_is_running(ctx); /* ctx is freed */ mutex_lock(&ctx->kdamond_lock); /* UAF */ (The race can also occur with damon_sysfs_kdamonds_rm_dirs() and damon_sysfs_kdamond_release(), which free or replace the context under damon_sysfs_lock.) Fix by taking damon_sysfs_lock before dereferencing the context, mirroring the locking used in pid_show(). The bug has existed since state_show() first accessed kdamond->damon_ctx.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
3.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 10

VendorProductVersionRange
linuxlinux_kernel*≥5.18  –  <6.1.153
linuxlinux_kernel*≥6.2  –  <6.6.107
linuxlinux_kernel*≥6.7  –  <6.12.48
linuxlinux_kernel*≥6.13  –  <6.16.8
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
debiandebian_linux11.0any

References 6

  • git.kernel.org https://git.kernel.org/stable/c/26d29b2ac87a2989071755f9828ebf839b560d4c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3260a3f0828e06f5f13fac69fb1999a6d60d9cff
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3858c44341ad49dc7544b19cc9f9ecffaa7cc50e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/4e87f461d61959647464a94d11ae15c011be58ce
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/60d7a3d2b985a395318faa1d88da6915fad11c19
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
    Mailing ListThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/26d29b2ac87a2989071755f9828ebf839b560d4c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3260a3f0828e06f5f13fac69fb1999a6d60d9cff
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3858c44341ad49dc7544b19cc9f9ecffaa7cc50e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/4e87f461d61959647464a94d11ae15c011be58ce
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/60d7a3d2b985a395318faa1d88da6915fad11c19
    Patch