{"id":"CVE-2026-64073","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nirq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT\n\nOn PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via\nrun_irq_workd(), so irq_work_sync() uses …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nirq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT\n\nOn PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via\nrun_irq_workd(), so irq_work_sync() uses …","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.16, < 6.1.175","linux_kernel >= 6.2, < 6.6.142","linux_kernel >= 6.7, < 6.12.92","linux_kernel >= 6.13, < 6.18.34","linux_kernel >= 6.19, < 7.0.11","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.11"],"published":"2026-07-19","updated":"2026-09-03","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64073","references":[{"url":"https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00132,"epssPercentile":0.03167,"ingestedAt":"2026-09-04T05:15:22.660Z","slug":"CVE-2026-64073","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nirq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT\n\nOn PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via\nrun_irq_workd(), so irq_work_sync() uses rcuwait() to wait for BUSY==0.\n\nAfter irq_work_single() clears BUSY via atomic_cmpxchg(), it still\ndereferences @work for irq_work_is_hard() and rcuwait_wake_up().\n\nAn irq_work_sync() caller on another CPU that enters after BUSY is cleared\ncan observe BUSY==0 immediately, return, and free the work before those\naccesses complete — causing a use-after-free.\n\nFix this by wrapping run_irq_workd() in guard(rcu)() so that the entire\nirq_work_single() execution is within an RCU read-side critical\nsection. Then add synchronize_rcu() in irq_work_sync() after\nrcuwait_wait_event() to ensure the caller waits for the RCU grace period\nbefore returning, preventing premature frees.\n\n## Affected\n\n- `linux_kernel >= 5.16, < 6.1.175`\n- `linux_kernel >= 6.2, < 6.6.142`\n- `linux_kernel >= 6.7, < 6.12.92`\n- `linux_kernel >= 6.13, < 6.18.34`\n- `linux_kernel >= 6.19, < 7.0.11`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.11`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}