{"id":"CVE-2026-98294","summary":"Bluetooth: hci_qca: Do not write to the serial port after it is closed","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_qca: Do not write to the serial port after it is closed\n\nhci_uart_close() closes the serdev port if HCI_QUIRK_NON_PERSISTENT_SETUP\nis set (for example, for the WCN399x family). A failed hci_dev_open_sync()\nfollowing a successful qca_setup() calls hdev-\u003eclose() but not\nhdev-\u003eshutdown(), so the port is closed while power-\u003evregs_on is left true.\nqca_serdev_remove() then passes its power-\u003evregs_on test and calls\nqca_power_off(), which writes to the closed port unconditionally.\n\nSeen on a WCN3988 by unbinding the driver after a controller failure. The\ntrace below is from a 7.0.0 based kernel, where qca_power_off() was still\nnamed qca_power_shutdown():\n\n  Unable to handle kernel NULL pointer dereference at virtual address\n  0000000000000038\n  Call trace:\n   tty_set_termios+0x50/0x238 (P)\n   ttyport_set_baudrate+0x84/0xc0\n   serdev_device_set_baudrate+0x24/0x40\n   qca_power_shutdown+0x158/0x1fc [hci_uart]\n   qca_serdev_remove+0x54/0x68 [hci_uart]\n   serdev_drv_remove+0x1c/0x2c\n   device_remove+0x4c/0x80\n   device_release_driver_internal+0x1cc/0x224\n   device_driver_detach+0x18/0x24\n   unbind_store+0xb4/0xc0\n\nCheck HCI_UART_PROTO_READY, which hci_uart_close() clears in the same place\nit closes the port, before writing to it. The regulator disable is left\nunconditional so the controller is still powered down.\n\nThe dangling serport-\u003etty that turns this into a use-after-free is\naddressed in a separate patch.","modified":"2026-10-08T02:52:56.584383782Z","published":"2026-10-06T08:45:53.338Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98294.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/15754e4ec47ac5d117c9609c34a49ed6980ac4a1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4e93c65f87825e1e012bce56615320aeb123815d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a5414b0a9464b863733c8bd97493cb443a210ec4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98294.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98294"},{"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":"fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3"},{"fixed":"a5414b0a9464b863733c8bd97493cb443a210ec4"},{"fixed":"15754e4ec47ac5d117c9609c34a49ed6980ac4a1"},{"fixed":"4e93c65f87825e1e012bce56615320aeb123815d"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98294.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.19.0"},{"fixed":"6.18.54"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98294.json"}}],"schema_version":"1.9.0"}