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.
References
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
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History
20 Jan 2026, 20:29
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
|
| CPE | cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* |
|
| CWE | CWE-416 | |
| References | () https://git.kernel.org/stable/c/26d29b2ac87a2989071755f9828ebf839b560d4c - Patch | |
| References | () https://git.kernel.org/stable/c/3260a3f0828e06f5f13fac69fb1999a6d60d9cff - Patch | |
| References | () https://git.kernel.org/stable/c/3858c44341ad49dc7544b19cc9f9ecffaa7cc50e - Patch | |
| References | () https://git.kernel.org/stable/c/4e87f461d61959647464a94d11ae15c011be58ce - Patch | |
| References | () https://git.kernel.org/stable/c/60d7a3d2b985a395318faa1d88da6915fad11c19 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory, Mailing List |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
23 Sep 2025, 06:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-09-23 06:15
Updated : 2026-01-20 20:29
NVD link : CVE-2025-39877
Mitre link : CVE-2025-39877
CVE.ORG link : CVE-2025-39877
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
CWE-416
Use After Free