{"id":"CVE-2026-89742","summary":"rapidio: mport_cdev: fix use-after-free in dma_req_free()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrapidio: mport_cdev: fix use-after-free in dma_req_free()\n\ndma_req_free() acquires buf_mutex through req-\u003emap, drops the mapping\nreference with kref_put(), and then dereferences req-\u003emap again to unlock\nthe mutex.\n\nIf kref_put() drops the last reference, mport_release_mapping() frees the\nmapping, and the subsequent mutex_unlock() dereferences a freed object. \nThis is a use-after-free.\n\nFix this by caching map and md before kref_put(), clearing req-\u003emap while\nholding buf_mutex, and using the cached md for mutex unlocking.\n\nThe bug is reachable from userspace via the RapidIO mport character device\ninterface.","modified":"2026-09-13T03:47:20.634932896Z","published":"2026-09-11T19:46:48.522Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89742.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9a9929ec875ff20922c90c96fd544ae8a2a61a8d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89742.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89742"},{"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":"e8de370188d098bb49483c287b44925957c3c9b6"},{"fixed":"9a9929ec875ff20922c90c96fd544ae8a2a61a8d"},{"fixed":"e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0"},{"fixed":"211c68d817a3d9dc14c0026a59da7cac30f8147e"},{"fixed":"5cbef379a94b161726c5f504598bf4791d45cedc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89742.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.6.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89742.json"}}],"schema_version":"1.9.0"}