{"id":"CVE-2026-98294","title":"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, f…","summary":"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, f…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 < a5414b0a9464b863733c8bd97493cb443a210ec4","Linux >= fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 < 15754e4ec47ac5d117c9609c34a49ed6980ac4a1","Linux >= fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 < 4e93c65f87825e1e012bce56615320aeb123815d","Linux 4.19"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T09:18:19.887","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98294","references":[{"url":"https://git.kernel.org/stable/c/15754e4ec47ac5d117c9609c34a49ed6980ac4a1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4e93c65f87825e1e012bce56615320aeb123815d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5414b0a9464b863733c8bd97493cb443a210ec4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-06T08:50:17.417Z","slug":"CVE-2026-98294","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}