CVE-2025-39877
- Source
- https://cve.org/CVERecord?id=CVE-2025-39877
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39877.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-39877
- Downstream
- Related
- Published
- 2025-09-23T06:00:48Z
- Modified
- 2026-08-12T03:30:28Z
- Summary
- mm/damon/sysfs: fix use-after-free in state_show()
- Details
-
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.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39877.json" }- References
-
- https://git.kernel.org/stable/c/26d29b2ac87a2989071755f9828ebf839b560d4c
- https://git.kernel.org/stable/c/3260a3f0828e06f5f13fac69fb1999a6d60d9cff
- https://git.kernel.org/stable/c/3858c44341ad49dc7544b19cc9f9ecffaa7cc50e
- https://git.kernel.org/stable/c/4e87f461d61959647464a94d11ae15c011be58ce
- https://git.kernel.org/stable/c/60d7a3d2b985a395318faa1d88da6915fad11c19
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39877.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-39877
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda61ea561c87139992fe32afdee48a6f6b85d824aFixed3858c44341ad49dc7544b19cc9f9ecffaa7cc50eFixed60d7a3d2b985a395318faa1d88da6915fad11c19Fixed26d29b2ac87a2989071755f9828ebf839b560d4cFixed4e87f461d61959647464a94d11ae15c011be58ceFixed3260a3f0828e06f5f13fac69fb1999a6d60d9cff