CVE-2026-46025: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rhpm-rxf4-q3hf",
  "modified" : "2026-06-16T18:32:28Z",
  "published" : "2026-05-27T15:33:21Z",
  "aliases" : [ "CVE-2026-46025" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damon_call() vs kdamond_fn() exit race\n\nPatch series \"mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit\nrace\".\n\ndamon_call() and damos_walk() can leak memory and/or deadlock when they\nrace with kdamond terminations.  Fix those.\n\n\nThis patch (of 2);\n\nWhen kdamond_fn() main loop is finished, the function cancels all\nremaining damon_call() requests and unset the damon_ctx->kdamond so that\nAPI callers and API functions themselves can know the context is\nterminated.  damon_call() adds the caller's request to the queue first. \nAfter that, it shows if the kdamond of the damon_ctx is still running\n(damon_ctx->kdamond is set).  Only if the kdamond is running, damon_call()\nstarts waiting for the kdamond's handling of the newly added request.\n\nThe damon_call() requests registration and damon_ctx->kdamond unset are\nprotected by different mutexes, though.  Hence, damon_call() could race\nwith damon_ctx->kdamond unset, and result in deadlocks.\n\nFor example, let's suppose kdamond successfully finished the damon_call()\nrequests cancelling.  Right after that, damon_call() is called for the\ncontext.  It registers the new request, and shows the context is still\nrunning, because damon_ctx->kdamond unset is not yet done.  Hence the\ndamon_call() caller starts waiting for the handling of the request. \nHowever, the kdamond is already on the termination steps, so it never\nhandles the new request.  As a result, the damon_call() caller threads\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\ncall_controls_obsolete.  It is protected by the\ndamon_ctx->call_controls_lock, which protects damon_call() requests\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of remaining\ndamon_call() requests is executed.  damon_call() reads the obsolete field\nunder the lock and avoids adding a new request.\n\nAfter this change, only requests that are guaranteed to be handled or\ncancelled are registered.  Hence the after-registration DAMON context\ntermination check is no longer needed.  Remove it together.\n\nNote that the deadlock will not happen when damon_call() is called for\nrepeat mode request.  In tis case, damon_call() returns instead of waiting\nfor the handling when the request registration succeeds and it shows the\nkdamond is running.  However, if the request also has dealloc_on_cancel,\nthe request memory would be leaked.\n\nThe issue is found by sashiko [1].",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-46025"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/2691332ad88b57179c38653e2cd613d5820a52cf"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/55da81663b9642dd046b26dd6f1baddbcf337c1e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e6a053a6f4b5048746c49432a5cc5b79fe4695fe"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-05-27T14:17:21Z"
  }
}