{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46008", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.092Z", "datePublished": "2026-05-27T12:56:08.315Z", "dateUpdated": "2026-10-21T12:41:10.467Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:41:10.467Z" }, "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]." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/damon.h", "mm/damon/core.c" ], "versions": [ { "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61", "lessThan": "93a7f297362deac614ce3dbbba73ff2ba31aaca3", "status": "affected", "versionType": "git" }, { "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61", "lessThan": "0ba956a239ba6e3fae8555d3660e22e675be63b5", "status": "affected", "versionType": "git" }, { "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61", "lessThan": "33c3f6c2b48cd84b441dba1ee3e62290e53930f4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/damon.h", "mm/damon/core.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.58", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.4", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.18.58" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.0.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/93a7f297362deac614ce3dbbba73ff2ba31aaca3" }, { "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" } } } }