{"id":"CVE-2026-90305","title":"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…","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c6e61c06d6061750597e79c598acb5dead44c35b < 8de56782d6e5ba7a9f8c820342dccde65502f93f","Linux >= c6e61c06d6061750597e79c598acb5dead44c35b < 8a58a41100ea377e978d99600ec24a9bd0273662","Linux 7.1"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:28.163","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90305","references":[{"url":"https://git.kernel.org/stable/c/8a58a41100ea377e978d99600ec24a9bd0273662","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8de56782d6e5ba7a9f8c820342dccde65502f93f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.828Z","epss":0.00189,"epssPercentile":0.08854,"slug":"CVE-2026-90305","body":"## Overview\n\nIn 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->siglock:\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().\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}