{"id":"CVE-2026-72069","revision":"725fd4e643134517941b7ef8b10084b5","records":[{"revision":"725fd4e643134517941b7ef8b10084b5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72069","aliases":[],"title":"locking/rt: Fix the incorrect RCU protection in rt_spin_unlock()","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.","state":0,"publishedAt":"2026-08-15T05:52:21.752+00:00","modifiedAt":"2026-10-19T21:19:26.463+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/locking/spinlock_rt.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"af28d801cd2db4cc7378554499bd4a5d84a5517e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"9d1fcd64ab81200e02b7a6db5eb1da8e244e8289\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"3cfaac77b3c32ac3940df28866de263c3f45d24c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"1f0d56d3f1e88f20f6e46109402f8c15d59bac37\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"633cadbc0b8323f5cc140a285d2432089dbb534e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"83f9fb561c1c3917e19f95523dd933c7d30291aa\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f383b6dc96e976dfbf2721b0bf10bd96103b341\",\n                            \"lessThan\": \"89038cc87d80c77e7aa6f42a64b2573b74af339f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/locking/spinlock_rt.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.217\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.184\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.148\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.101\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 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,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/af28d801cd2db4cc7378554499bd4a5d84a5517e","https://git.kernel.org/stable/c/9d1fcd64ab81200e02b7a6db5eb1da8e244e8289","https://git.kernel.org/stable/c/3cfaac77b3c32ac3940df28866de263c3f45d24c","https://git.kernel.org/stable/c/1f0d56d3f1e88f20f6e46109402f8c15d59bac37","https://git.kernel.org/stable/c/633cadbc0b8323f5cc140a285d2432089dbb534e","https://git.kernel.org/stable/c/83f9fb561c1c3917e19f95523dd933c7d30291aa","https://git.kernel.org/stable/c/89038cc87d80c77e7aa6f42a64b2573b74af339f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72069","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72069","identifiers":["CVE-2026-72069"]},"retained":false,"historicalAffected":[]}],"coverage":[]}