{"cve":"CVE-2022-50563","nvd":{"published":"2025-10-22T14:15:41.067","modified":"2026-06-17T05:23:47.900","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm thin: Fix UAF in run_timer_softirq()\n\nWhen dm_resume() and dm_destroy() are concurrent, it will\nlead to UAF, as follows:\n\n BUG: KASAN: use-after-free in __run_timers+0x173/0x710\n Write of size 8 at addr ffff88816d9490f0 by task swapper/0/0\n<snip>\n Call Trace:\n  <IRQ>\n  dump_stack_lvl+0x73/0x9f\n  print_report.cold+0x132/0xaa2\n  _raw_spin_lock_irqsave+0xcd/0x160\n  __run_timers+0x173/0x710\n  kasan_report+0xad/0x110\n  __run_timers+0x173/0x710\n  __asan_store8+0x9c/0x140\n  __run_timers+0x173/0x710\n  call_timer_fn+0x310/0x310\n  pvclock_clocksource_read+0xfa/0x250\n  kvm_clock_read+0x2c/0x70\n  kvm_clock_get_cycles+0xd/0x20\n  ktime_get+0x5c/0x110\n  lapic_next_event+0x38/0x50\n  clockevents_program_event+0xf1/0x1e0\n  run_timer_softirq+0x49/0x90\n  __do_softirq+0x16e/0x62c\n  __irq_exit_rcu+0x1fa/0x270\n  irq_exit_rcu+0x12/0x20\n  sysvec_apic_timer_interrupt+0x8e/0xc0\n\nOne of the concurrency UAF can be shown as below:\n\n        use                                  free\ndo_resume                           |\n  __find_device_hash_cell           |\n    dm_get                          |\n      atomic_inc(&md->holders)      |\n                                    | dm_destroy\n                                    |   __dm_destroy\n                                    |     if (!dm_suspended_md(md))\n                                    |     atomic_read(&md->holders)\n                                    |     msleep(1)\n  dm_resume                         |\n    __dm_resume                     |\n      dm_table_resume_targets       |\n        pool_resume                 |\n          do_waker  #add delay work |\n  dm_put                            |\n    atomic_dec(&md->holders)        |\n                                    |     dm_table_destroy\n                                    |       pool_dtr\n                                    |         __pool_dec\n                                    |           __pool_destroy\n                                    |             destroy_workqueue\n                                    |             kfree(pool) # free pool\n        time out\n__do_softirq\n  run_timer_softirq # pool has already been freed\n\nThis can be easily reproduced using:\n  1. create thin-pool\n  2. dmsetup suspend pool\n  3. dmsetup resume pool\n  4. dmsetup remove_all # Concurrent with 3\n\nThe root cause of this UAF bug is that dm_resume() adds timer after\ndm_destroy() skips cancelling the timer because of suspend status.\nAfter timeout, it will call run_timer_softirq(), however pool has\nalready been freed. The concurrency UAF bug will happen.\n\nTherefore, cancelling timer again in __pool_destroy().","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/34cd15d83b7206188d440b29b68084fcafde9395","https://git.kernel.org/stable/c/34fe9c2251f19786a6689149a6212c6c0de1d63b","https://git.kernel.org/stable/c/550a4fac7ecfee5bac6a0dd772456ca62fb72f46","https://git.kernel.org/stable/c/7ae6aa649394e1e7f6dafb55ce0d578c0572a280","https://git.kernel.org/stable/c/7ee059d06a5d3c15465959e0472993e80fbe4e81"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:12:35.277909958+00:00"},"epss":{"cve":"CVE-2022-50563","score":0.00249,"percentile":0.16224,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}