{"api_version":"1","generated_at":"2026-06-04T11:55:56+00:00","cve":"CVE-2026-46008","urls":{"html":"https://cve.report/CVE-2026-46008","api":"https://cve.report/api/cve/CVE-2026-46008.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-46008","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46008"},"summary":{"title":"mm/damon/core: fix damos_walk() vs kdamond_fn() exit race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damos_walk() vs kdamond_fn() exit race\n\nWhen kdamond_fn() main loop is finished, the function cancels remaining\ndamos_walk() request and unset the damon_ctx->kdamond so that API callers\nand API functions themselves can show the context is terminated. \ndamos_walk() adds the caller's request to the queue first.  After that, it\nshows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond\nis set).  Only if the kdamond is running, damos_walk() starts waiting for\nthe kdamond's handling of the newly added request.\n\nThe damos_walk() requests registration and damon_ctx->kdamond unset are\nprotected by different mutexes, though.  Hence, damos_walk() could race\nwith damon_ctx->kdamond unset, and result in deadlocks.\n\nFor example, let's suppose kdamond successfully finished the damow_walk()\nrequest cancelling.  Right after that, damos_walk() 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\ndamos_walk() 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 damos_walk() caller thread\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\nwalk_control_obsolete.  It is protected by the\ndamon_ctx->walk_control_lock, which protects damos_walk() request\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of the\nremaining damos_walk() request is executed.  damos_walk() reads the\nobsolete field under 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\nThe issue is found by sashiko [1].","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:17:18","updated_at":"2026-05-27 14:48:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5","name":"https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4","name":"https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-46008","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46008","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 0ba956a239ba6e3fae8555d3660e22e675be63b5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 33c3f6c2b48cd84b441dba1ee3e62290e53930f4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.4 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"46008","cve":"CVE-2026-46008","epss":"0.000180000","percentile":"0.052520000","score_date":"2026-06-01","updated_at":"2026-06-02 00:05:21"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/linux/damon.h","mm/damon/core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"0ba956a239ba6e3fae8555d3660e22e675be63b5","status":"affected","version":"bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61","versionType":"git"},{"lessThan":"33c3f6c2b48cd84b441dba1ee3e62290e53930f4","status":"affected","version":"bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/damon.h","mm/damon/core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.14"},{"lessThan":"6.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.4","versionStartIncluding":"6.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"6.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damos_walk() vs kdamond_fn() exit race\n\nWhen kdamond_fn() main loop is finished, the function cancels remaining\ndamos_walk() request and unset the damon_ctx->kdamond so that API callers\nand API functions themselves can show the context is terminated. \ndamos_walk() adds the caller's request to the queue first.  After that, it\nshows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond\nis set).  Only if the kdamond is running, damos_walk() starts waiting for\nthe kdamond's handling of the newly added request.\n\nThe damos_walk() requests registration and damon_ctx->kdamond unset are\nprotected by different mutexes, though.  Hence, damos_walk() could race\nwith damon_ctx->kdamond unset, and result in deadlocks.\n\nFor example, let's suppose kdamond successfully finished the damow_walk()\nrequest cancelling.  Right after that, damos_walk() 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\ndamos_walk() 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 damos_walk() caller thread\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\nwalk_control_obsolete.  It is protected by the\ndamon_ctx->walk_control_lock, which protects damos_walk() request\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of the\nremaining damos_walk() request is executed.  damos_walk() reads the\nobsolete field under 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\nThe issue is found by sashiko [1]."}],"providerMetadata":{"dateUpdated":"2026-05-27T12:56:08.315Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5"},{"url":"https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4"}],"title":"mm/damon/core: fix damos_walk() vs kdamond_fn() exit race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-46008","datePublished":"2026-05-27T12:56:08.315Z","dateReserved":"2026-05-13T15:03:33.092Z","dateUpdated":"2026-05-27T12:56:08.315Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:17:18","lastModifiedDate":"2026-05-27 14:48:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"46008","Ordinal":"1","Title":"mm/damon/core: fix damos_walk() vs kdamond_fn() exit race","CVE":"CVE-2026-46008","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"46008","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damos_walk() vs kdamond_fn() exit race\n\nWhen kdamond_fn() main loop is finished, the function cancels remaining\ndamos_walk() request and unset the damon_ctx->kdamond so that API callers\nand API functions themselves can show the context is terminated. \ndamos_walk() adds the caller's request to the queue first.  After that, it\nshows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond\nis set).  Only if the kdamond is running, damos_walk() starts waiting for\nthe kdamond's handling of the newly added request.\n\nThe damos_walk() requests registration and damon_ctx->kdamond unset are\nprotected by different mutexes, though.  Hence, damos_walk() could race\nwith damon_ctx->kdamond unset, and result in deadlocks.\n\nFor example, let's suppose kdamond successfully finished the damow_walk()\nrequest cancelling.  Right after that, damos_walk() 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\ndamos_walk() 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 damos_walk() caller thread\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\nwalk_control_obsolete.  It is protected by the\ndamon_ctx->walk_control_lock, which protects damos_walk() request\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of the\nremaining damos_walk() request is executed.  damos_walk() reads the\nobsolete field under 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\nThe issue is found by sashiko [1].","Type":"Description","Title":"mm/damon/core: fix damos_walk() vs kdamond_fn() exit race"}]}}}