{"id":"CVE-2026-64073","summary":"irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT","details":"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 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.","modified":"2026-07-22T03:31:34.756499052Z","published":"2026-07-19T15:39:48.463Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64073.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442"},{"type":"WEB","url":"https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64073.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64073"},{"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":"810979682ccc98dbd83f341c18a2e556c30a7164"},{"fixed":"2dc79362302922cb18f35e262712b5e58de65442"},{"fixed":"eef4f71b46a9929ac33e968538c9dd5d96a02460"},{"fixed":"684a78183c54c23e70d1cba320f7fc184604210b"},{"fixed":"18c0456ea2615b1a743a6db739c74411c3b42bc6"},{"fixed":"81b582784518196eff1050212a046bc29d3a05dd"},{"fixed":"91840be8f710370607f949a627e070896faeddb8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64073.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64073.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}