{"id":"CVE-2026-98656","kind":"vulnerability","aliases":["CVE-2026-98656"],"related":[],"title":"Linux kernel IIO: deferred trigger work can touch freed memory","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niio: trigger: cancel reenable_work before freeing trigger\n\niio_trigger_notify_done_atomic() defers ->reenable() into\ntrig->reenable_work on the system workqueue, and the worker dereferences\nthe owning trigger through container_of().  Nothing cancels this work\nbefore iio_trig_release() frees the trigger, so a worker armed by the\nlast in-flight IRQ can outlive the free and touch freed memory.\n\nCancel it at the top of iio_trig_release(), which every free path\nreaches through the device core's final put_device().\n\nFound by an in-house static analysis tool.","summary":"The Linux kernel's IIO trigger subsystem can leave a deferred work item armed after the trigger is freed, so the worker later reads freed memory. The sources do not state what an attacker can gain from this use-after-free.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["embedded","iio","infrastructure","linux-kernel"],"not_affected_if":["no-iio-triggers"],"how_to_check":"- unknown","fix":"- Install a Linux kernel release that includes the upstream commit adding cancel_work_sync on trig->reenable_work in iio_trig_release(); the sources do not name the fixed version numbers.","status":"open","published_at":"2026-10-18T16:17:18+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","triaged_at":"2026-10-25T05:19:35+00:00","updated_at":"2026-10-25T05:19:35+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-10-25T05:19:35Z","model":"claude-haiku-5-5","output":{"fix":"- Install a Linux kernel release that includes the upstream commit adding cancel_work_sync on trig->reenable_work in iio_trig_release(); the sources do not name the fixed version numbers.","reach":"local","title":"Linux kernel IIO: deferred trigger work can touch freed memory","impact":"medium","summary":"The Linux kernel's IIO trigger subsystem can leave a deferred work item armed after the trigger is freed, so the worker later reads freed memory. The sources do not state what an attacker can gain from this use-after-free.","category":"infrastructure","nicknames":[],"who_cares":["linux-kernel","iio","embedded"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown; a use-after-free in kernel memory, impact not stated","analyst_note":"Check the NVD entry and the upstream kernel commit for the fixed kernel versions and whether the bug is reachable by an unprivileged user.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["no-iio-triggers"],"who_is_affected":"Systems running a Linux kernel without this fix that load IIO (Industrial I/O) trigger drivers for sensors and use triggered buffered capture. The sources do not say which hardware or configurations are exposed; systems without IIO triggers are unlikely to be affected.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000597,"input_tokens":3430,"output_tokens":508,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-98656':13A,16A 'analysi':167C 'arm':36B,122C 'atom':87C 'attack':56B 'cancel':77C,109C,138C 'contain':106C 'core':155C 'cve':11A,14A 'defer':4A,33B,88C 'derefer':101C 'devic':154C,159C 'done':86C 'embed':17B 'everi':148C 'final':157C 'flight':128C 'follow':70C 'found':160C 'free':64B,81C,116C,133C,149C 'freed':9A,41B,47B,136C 'gain':58B 'hous':165C 'iio':3A,18B,27B,75C,83C,113C,144C 'in-flight':126C 'in-hous':163C 'infrastructur':19B 'irq':129C 'item':35B 'kernel':2A,22B,25B,68C 'last':125C 'later':45B 'leav':31B 'linux':1A,21B,24B,67C 'linux-kernel':20B 'memori':10A,48B,137C 'noth':108C 'notifi':85C 'outliv':131C 'own':103C 'path':150C 'put':158C 'reach':151C 'read':46B 'reenabl':78C,89C,92C 'releas':115C,146C 'resolv':74C 'sourc':50B 'state':53B 'static':166C 'subsystem':29B 'system':96C 'tool':168C 'top':142C 'touch':8A,135C 'trig':91C,114C,145C 'trigger':5A,28B,39B,76C,82C,84C,104C,118C 'use':62B 'use-after-fre':61B 'vulner':71C 'work':6A,34B,79C,93C,111C 'worker':44B,100C,121C 'workqueu':97C","nicknames":[],"mitigations":[],"who_affected":"Systems running a Linux kernel without this fix that load IIO (Industrial I/O) trigger drivers for sensors and use triggered buffered capture. The sources do not say which hardware or configurations are exposed; systems without IIO triggers are unlikely to be affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:18+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98656","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98656","severity":null,"published_at":"2026-10-18T16:17:18+00:00","modified_at":"2026-10-21T13:21:33+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","fetched_at":"2026-10-23T22:28:56+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}