{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-39877",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2025-39877"
  ],
  "published": "2025-09-23T06:01:33Z",
  "summary": "mm/damon/sysfs: fix use-after-free in state_show()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: fix use-after-free in state_show()\n\nstate_show() reads kdamond->damon_ctx without holding damon_sysfs_lock. \nThis allows a use-after-free race:\n\nCPU 0                         CPU 1\n-----                         -----\nstate_show()                  damon_sysfs_turn_damon_on()\nctx = kdamond->damon_ctx;     mutex_lock(&damon_sysfs_lock);\n                              damon_destroy_ctx(kdamond->damon_ctx);\n                              kdamond->damon_ctx = NULL;\n                              mutex_unlock(&damon_sysfs_lock);\ndamon_is_running(ctx);        /* ctx is freed */\nmutex_lock(&ctx->kdamond_lock); /* UAF */\n\n(The race can also occur with damon_sysfs_kdamonds_rm_dirs() and\ndamon_sysfs_kdamond_release(), which free or replace the context under\ndamon_sysfs_lock.)\n\nFix by taking damon_sysfs_lock before dereferencing the context, mirroring\nthe locking used in pid_show().\n\nThe bug has existed since state_show() first accessed kdamond->damon_ctx.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.153",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-39877"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3858c44341ad49dc7544b19cc9f9ecffaa7cc50e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/60d7a3d2b985a395318faa1d88da6915fad11c19"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/26d29b2ac87a2989071755f9828ebf839b560d4c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4e87f461d61959647464a94d11ae15c011be58ce"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3260a3f0828e06f5f13fac69fb1999a6d60d9cff"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}