{"cve":"CVE-2026-72069","nvd":{"published":"2026-08-15T06:21:16.607","modified":"2026-10-19T22:17:25.740","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlocking/rt: Fix the incorrect RCU protection in rt_spin_unlock()\n\nrt_spin_unlock() releases the RCU protection before unlocking the\nlock. That opens the door for the following UAF scenario:\n\n T1\t\t\t\t\tT2\n spin_lock(&p->lock);\t\trcu_read_lock();\n invalidate(p);\t\t\tp = rcu_dereference(ptr);\n rcu_assign_pointer(ptr, NULL);\tif (!p) return;\n spin_unlock(&p->lock);\t\tspin_lock(&p->lock)\n \t\t\t\t   lock(&lock->lock);\n\t\t\t\t   rcu_read_lock();\n kfree_rcu(p);\t\t\trcu_read_unlock();\n\t\t\t\t....\n\t\t\t\tspin_unlock(&p->lock)\n\t\t\t\t  rcu_read_unlock(); // Ends grace period\n rcu_do_batch()\n   kfree(p);\n\t\t\t    UAF ->\t  rt_mutex_cmpxchg_release(&lock->lock...)\n\nRegular spinlocks keep preemption disabled accross the unlock operation,\nwhich provides full RCU protection, but the RT substitution fails to\nresemble that. Same applies for the rwlock substitution.\n\nMove the rcu_read_unlock() invocation past the unlock operations to match\nthe non-RT semantics. This makes it asymmetric vs. rt_xxx_lock(), but\nthat's harmless as the caller needs to hold RCU read lock across the lock\noperation. The migrate_enable() call stays before the unlock operation\nbecause there is no per CPU operation in the unlock path which would\nrequire migration to be kept disabled.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1f0d56d3f1e88f20f6e46109402f8c15d59bac37","https://git.kernel.org/stable/c/3cfaac77b3c32ac3940df28866de263c3f45d24c","https://git.kernel.org/stable/c/633cadbc0b8323f5cc140a285d2432089dbb534e","https://git.kernel.org/stable/c/83f9fb561c1c3917e19f95523dd933c7d30291aa","https://git.kernel.org/stable/c/89038cc87d80c77e7aa6f42a64b2573b74af339f"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:56:58.798400159+00:00"},"epss":{"cve":"CVE-2026-72069","score":0.00728,"percentile":0.5391,"date":"2026-10-25"},"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."]}