{"cve":"CVE-2026-93050","nvd":{"published":"2026-09-17T17:17:58.367","modified":"2026-10-19T10:16:54.790","status":"Received","description":"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->dev)\n   dereferences ipoctal->dev after the ipack_device has been freed\n   by ipack_device_del().  Fix by caching ipoctal->carrier_owner\n   during probe() and calling module_put() on the cached pointer\n   directly in cleanup(), avoiding any access to ipoctal->dev.\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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1a3258e105f711538201bdd2ac2a05b11554eabc","https://git.kernel.org/stable/c/4a6518be316029650301f2a5e8f0def229b895d9","https://git.kernel.org/stable/c/a4613140f01bd0fb9980e2746ed9aaa65a29b5d6","https://git.kernel.org/stable/c/ab5f5b27a340004b92252c6a5f23bf1c6cf3b02a","https://git.kernel.org/stable/c/b6b5d64cb161a28347d64dc3168a636c4abb68d5"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-93050","score":0.00205,"percentile":0.10438,"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."]}