{"id":"CVE-2026-90317","summary":"bpf: Invalidate RCU pointers after final spin unlock","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Invalidate RCU pointers after final spin unlock\n\nIn a sleepable BPF program, a spin lock can provide the only RCU protection\nfor a kptr. The final bpf_spin_unlock() ends that protection, but the\nverifier leaves the pointer valid. Another CPU can then free the object\nbefore the pointer is used. A capability-limited runtime PoC triggered a\ntask_struct use-after-free in __bpf_get_task_stack().\n\nRecord whether the program is in an RCU-protected context before releasing\nthe lock. Invalidate RCU-protected pointers only when the unlock leaves the\nfinal such context. This preserves valid pointers in non-sleepable programs\nand inside an explicit RCU read-side section.","modified":"2026-09-18T03:48:37.784636151Z","published":"2026-09-17T16:08:35.537Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90317.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/180c7000712db77063b3a26f4c97e7dd9038f449"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7ae71629357d0a6d0bdadb929c7b296d5b7e61c2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90317.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90317"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5861d1e8dbc4e1a03ebffb96ac041026cdd34c07"},{"fixed":"7ae71629357d0a6d0bdadb929c7b296d5b7e61c2"},{"fixed":"180c7000712db77063b3a26f4c97e7dd9038f449"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90317.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.6.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90317.json"}}],"schema_version":"1.9.0"}