CVE-2026-98294
Bluetooth: hci_qca: Do not write to the serial port after it is closed
No known exploitation. EPSS puts it in the 6th percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- LinuxAffected: ≥ fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3, < a5414b0a9464b863733c8bd97493cb443a210ec4Upgrade to: a5414b0a9464b863733c8bd97493cb443a210ec4Affected: ≥ fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3, < 15754e4ec47ac5d117c9609c34a49ed6980ac4a1Upgrade to: 15754e4ec47ac5d117c9609c34a49ed6980ac4a1Affected: ≥ fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3, < 4e93c65f87825e1e012bce56615320aeb123815dUpgrade to: 4e93c65f87825e1e012bce56615320aeb123815dStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_qca: Do not write to the serial port after it is closed hci_uart_close() closes the serdev port if HCI_QUIRK_NON_PERSISTENT_SETUP is set (for example, for the WCN399x family). A failed hci_dev_open_sync() following a successful qca_setup() calls hdev->close() but not hdev->shutdown(), so the port is closed while power->vregs_on is left true. qca_serdev_remove() then passes its power->vregs_on test and calls qca_power_off(), which writes to the closed port unconditionally. Seen on a WCN3988 by unbinding the driver after a controller failure. The trace below is from a 7.0.0 based kernel, where qca_power_off() was still named qca_power_shutdown(): Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038 Call trace: tty_set_termios+0x50/0x238 (P) ttyport_set_baudrate+0x84/0xc0 serdev_device_set_baudrate+0x24/0x40 qca_power_shutdown+0x158/0x1fc [hci_uart] qca_serdev_remove+0x54/0x68 [hci_uart] serdev_drv_remove+0x1c/0x2c device_remove+0x4c/0x80 device_release_driver_internal+0x1cc/0x224 device_driver_detach+0x18/0x24 unbind_store+0xb4/0xc0 Check HCI_UART_PROTO_READY, which hci_uart_close() clears in the same place it closes the port, before writing to it. The regulator disable is left unconditional so the controller is still powered down. The dangling serport->tty that turns this into a use-after-free is addressed in a separate patch.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.2% chance of exploitation activity in the next 30 days, which ranks it in the 6th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
2 events over 0 days, from the signal feeds we watch.
- Publishedrecord updated
Affected products
Sources
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