{"id":"CVE-2026-74593","summary":"sched_ext: Take cgroup_lock() first in scx_cgroup_lock()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Take cgroup_lock() first in scx_cgroup_lock()\n\nscx_cgroup_lock() write-locks scx_cgroup_ops_rwsem and then takes\ncgroup_lock(), which can deadlock through kernfs:\n\n  scx enable/disable         cgroup rmdir           cpu.weight write\n  ------------------         ------------           ----------------\n                             cgroup_lock()\n  percpu_down_write(rwsem)\n  cgroup_lock()\n                                                    kernfs_get_active()\n                                                    percpu_down_read(rwsem)\n                             kernfs_drain()\n\nThe enable path waits for the rmdir to release cgroup_mutex. The rmdir,\ndeactivating the cpu controller's files, waits in kernfs_drain() for the\nwrite's active reference. The write, in scx_group_set_weight(), waits for\nthe rwsem behind the pending writer.\n\nTake cgroup_lock() first. The set_* paths take no cgroup locks inside the\nread side, so a pending write-lock then only waits for read sections that\nalways run to completion, and no dependency from the rwsem back to\ncgroup_mutex remains.","modified":"2026-08-25T03:51:50.170659083Z","published":"2026-08-22T15:31:44.160Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74593.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2ca6b43edf83f8fc368cc3094ee5f3b1e8e0b0f0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5f8b69642d18e1f3e11996707842ac530444e959"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a054c9ffa9b7a0dffb763837b91ac9d381ec6d10"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74593.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74593"},{"type":"PACKAGE","url":"https://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":[{"introduced":"a5bd6ba30b3364354269b81ac55c2edca9a96d6d"},{"fixed":"2ca6b43edf83f8fc368cc3094ee5f3b1e8e0b0f0"},{"fixed":"a054c9ffa9b7a0dffb763837b91ac9d381ec6d10"},{"fixed":"5f8b69642d18e1f3e11996707842ac530444e959"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74593.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.46"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74593.json"}}],"schema_version":"1.9.0"}