From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 414663E0093 for ; Tue, 6 Oct 2026 10:26:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791282389; cv=none; b=iKTDgdlEqexPIugGTlz7QZEzKOv6YNUDB+xg+kZH9R9WX9ur4yCztwTHRNxoqQhc+RaM1+CdFpJupUeZRgIGWOqRj5MVMmiEced3/ND+XWHwLjX3BPRVvVKs2XPMnlLb+d67v/fzlFLnjMwBlsdvLv3qkIMxp27i5wlIh8PxPlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791282389; c=relaxed/simple; bh=48MTSORnIgwscM/1jkElXRZmQbcwHaFwp/mcXJ6zBA4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LryuQX2E88EydJ3UnTMHTpyEQi859MKArFJ6hKPFLxDlXMQ5mrwnTcUzJ88WWOoJQESonR3f74QuFyfszyjXXd5gBOZ+yJZrtjLOkOeuP8gSFMGpG2+arboowi4FbxSNZPNNh6F/Rtx0eyrWcbQtDWycLdF+/1KZOxlL6aiEZIc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=R97sK2A/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="R97sK2A/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30F9D1F000FF; Tue, 6 Oct 2026 10:26:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791282387; bh=b6mHsGND//ivzoey5HvzwPf8P32vyT9KdG1tVXyxOxE=; h=From:To:Cc:Subject:Date:Reply-To; b=R97sK2A/2CYXDgI34y2l6Dlw/5v7LbSPn7ItgXDOCW1hygDbObpjr7B1l/UuRxMiW Zmao/vTLHnQ19Xq/RLMIEmTcyyjdTt00oEkBuvggtNuztUS6+R4I8qeSKjEFhLdt54 tEakB4exWPEVMjYRnd0+SasRJO2M56zJyDxYUUgI= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-98294: Bluetooth: hci_qca: Do not write to the serial port after it is closed Date: Tue, 6 Oct 2026 10:46:35 +0200 Message-ID: <2026100607-CVE-2026-98294-95ae@gregkh> X-Mailer: git-send-email 2.56.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3405; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=FcHXZMm/uWI+9uMyYnO0IHu8RffBh+LRCVpzRZ9bBhQ=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlHtgrH3HOuap++fA33thZ9jfMPzNwSLNQttvCeV47/X NBz0W1XRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEwk5wnDfO81As9ZfPVyuVbo uLfE1diI5Re3McxTCzRomLWSo+J4/OyNm1+cKvOOOBgDAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== 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. The Linux kernel CVE team has assigned CVE-2026-98294 to this issue. Affected and fixed versions =========================== Issue introduced in 4.19 with commit fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 and fixed in 6.18.54 with commit a5414b0a9464b863733c8bd97493cb443a210ec4 Issue introduced in 4.19 with commit fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 and fixed in 7.2.8 with commit 15754e4ec47ac5d117c9609c34a49ed6980ac4a1 Issue introduced in 4.19 with commit fa9ad876b8e0ebd2b4367ef1580f89be64ebd5d3 and fixed in 7.3-rc4 with commit 4e93c65f87825e1e012bce56615320aeb123815d Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-98294 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/bluetooth/hci_qca.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/a5414b0a9464b863733c8bd97493cb443a210ec4 https://git.kernel.org/stable/c/15754e4ec47ac5d117c9609c34a49ed6980ac4a1 https://git.kernel.org/stable/c/4e93c65f87825e1e012bce56615320aeb123815d