{"id":"CVE-2026-93050","summary":"ipack: ipoctal: fix UAF, null-ptr-deref, and use-after-free in cleanup on remove","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipack: ipoctal: fix UAF, null-ptr-deref, and use-after-free in cleanup on remove\n\nThree issues arise when the device is removed while a tty session is\nstill active:\n\n1. UAF of struct ipoctal: the remove callback frees ipoctal via\n   kfree() while tty ops may still access it.  Fix by introducing\n   kref-based lifetime management — kref is taken in install() when\n   a tty is opened and released in cleanup() when the tty is finally\n   destroyed; remove() uses kref_put() instead of kfree().\n\n2. NULL dereference in ipoctal_write_tty(): __ipoctal_remove()\n   frees xmit_buf via tty_port_free_xmit_buf() while a userspace\n   process may still hold the tty fd and call write().  Fix by\n   checking for NULL xmit_buf in ipoctal_write_tty().\n\n3. UAF in ipoctal_cleanup(): ipack_put_carrier(ipoctal-\u003edev)\n   dereferences ipoctal-\u003edev after the ipack_device has been freed\n   by ipack_device_del().  Fix by caching ipoctal-\u003ecarrier_owner\n   during probe() and calling module_put() on the cached pointer\n   directly in cleanup(), avoiding any access to ipoctal-\u003edev.\n\nAlso introduce a \"removed\" flag in struct ipoctal, set at the start\nof __ipoctal_remove(), and checked in every tty op that accesses\nhardware resources (port_activate, write_tty, set_termios, hangup,\nshutdown).  This prevents page faults when devm_ioremap() regions\nare unmapped after remove() returns.","modified":"2026-09-19T03:47:31.039969926Z","published":"2026-09-17T16:10:40.360Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93050.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a3258e105f711538201bdd2ac2a05b11554eabc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a6518be316029650301f2a5e8f0def229b895d9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a4613140f01bd0fb9980e2746ed9aaa65a29b5d6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab5f5b27a340004b92252c6a5f23bf1c6cf3b02a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b6b5d64cb161a28347d64dc3168a636c4abb68d5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c92ef8fd834521f0b788e0511976c689fe57c63c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93050.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93050"},{"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":"05e5027efc9c0bb6d1d04cde279afbafca0a7929"},{"fixed":"ab5f5b27a340004b92252c6a5f23bf1c6cf3b02a"},{"fixed":"c92ef8fd834521f0b788e0511976c689fe57c63c"},{"fixed":"a4613140f01bd0fb9980e2746ed9aaa65a29b5d6"},{"fixed":"1a3258e105f711538201bdd2ac2a05b11554eabc"},{"fixed":"4a6518be316029650301f2a5e8f0def229b895d9"},{"fixed":"b6b5d64cb161a28347d64dc3168a636c4abb68d5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93050.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.8.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93050.json"}}],"schema_version":"1.9.0"}