{"id":"CVE-2026-90305","summary":"ARM: 9483/1: select HAVE_POSIX_CPU_TIMERS_TASK_WORK","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nARM: 9483/1: select HAVE_POSIX_CPU_TIMERS_TASK_WORK\n\nCommit c6e61c06d606 (\"ARM: 9463/1: Allow to enable RT\") enabled PREEMPT_RT\non ARM but did not select HAVE_POSIX_CPU_TIMERS_TASK_WORK. This leaves\nCONFIG_POSIX_CPU_TIMERS_TASK_WORK disabled, so CPU timers expire in hard\nIRQ context.\n\nOn PREEMPT_RT this makes run_posix_cpu_timers() take the sleeping\nsighand-\u003esiglock:\n\n  BUG: sleeping function called from invalid context at spinlock_rt.c:48\n    rt_spin_lock from lock_task_sighand\n    lock_task_sighand from run_posix_cpu_timers\n    run_posix_cpu_timers from update_process_times\n\nARM handles TIF_NOTIFY_RESUME on all return-to-user paths, including v7-M.\nARM32 KVM host support was removed by commit 541ad0150ca4 (\"arm: Remove\n32bit KVM host support\"), so the select need not be conditional on KVM.\n\nSelect it to defer POSIX CPU timer expiry to task context.\n\nReproduced with setrlimit(RLIMIT_CPU, ...) and a busy loop. The same path\nis used by setitimer(ITIMER_PROF or ITIMER_VIRTUAL) and POSIX CPU timers\ncreated with timer_create().","modified":"2026-09-19T03:47:28.864809436Z","published":"2026-09-17T16:08:27.742Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90305.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/8a58a41100ea377e978d99600ec24a9bd0273662"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8de56782d6e5ba7a9f8c820342dccde65502f93f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90305.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90305"},{"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":"c6e61c06d6061750597e79c598acb5dead44c35b"},{"fixed":"8de56782d6e5ba7a9f8c820342dccde65502f93f"},{"fixed":"8a58a41100ea377e978d99600ec24a9bd0273662"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90305.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90305.json"}}],"schema_version":"1.9.0"}