Answer in brief
CVE-2025-39877 records a High severity (CVSS 7.8) vulnerability in mm/damon/sysfs: fix use-after-free in state_show(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a61ea561c87139992fe32afdee48a6f6b85d824a <3858c44341ad49dc7544b19cc9f9ecffaa7cc50e || >=a61ea561c87139992fe32afdee48a6f6b85d824a <60d7a3d2b985a395318faa1d88da6915fad11c19 || >=a61ea561c87139992fe32afdee48a6f6b85d824a <26d29b2ac87a2989071755f9828ebf839b560d4c || >=a61ea561c87139992fe32afdee48a6f6b85d824a <4e87f461d61959647464a94d11ae15c011be58ce || >=a61ea561c87139992fe32afdee48a6f6b85d824a <3260a3f0828e06f5f13fac69fb1999a6d60d9cff | 3858c44341ad49dc7544b19cc9f9ecffaa7cc50e, 60d7a3d2b985a395318faa1d88da6915fad11c19, 26d29b2ac87a2989071755f9828ebf839b560d4c, 4e87f461d61959647464a94d11ae15c011be58ce, 3260a3f0828e06f5f13fac69fb1999a6d60d9cff |
| Linux/Linuxgeneric | 5.18 | Not reported |
Published upstream
Sep 23, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
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.
Quoted source text, attributed separately from HOL analysis.