{"id":"CVE-2026-98294","published":"2026-10-06T09:18:19.887","lastModified":"2026-10-06T09:18:19.887","description":"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->close() but not\nhdev->shutdown(), so the port is closed while power->vregs_on is left true.\nqca_serdev_remove() then passes its power->vregs_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->tty that turns this into a use-after-free is\naddressed in a separate patch.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/15754e4ec47ac5d117c9609c34a49ed6980ac4a1","tags":[]},{"url":"https://git.kernel.org/stable/c/4e93c65f87825e1e012bce56615320aeb123815d","tags":[]},{"url":"https://git.kernel.org/stable/c/a5414b0a9464b863733c8bd97493cb443a210ec4","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}