{"id":"AZL-102318","summary":"CVE-2026-93050 affecting package kernel 6.6.150.1-1","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":"2026-09-18T14:18:02.636402488Z","published":"2026-09-17T17:17:58Z","upstream":["CVE-2026-93050"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93050"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-102318.json"}}],"schema_version":"1.9.0"}