From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 124FD189BB0; Sun, 7 Sep 2025 20:21:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757276513; cv=none; b=nL1CZtWuB3kkZC2eLKDMBWOkps76HQAYpPTnRzxkHKUc997jAWRjs6QP+xoD1ZlJUi9b3EZiYdGXJlw8U7IphIbBGidaeOXVhA8QZTs3X2DVSvldrmFeWllzj/HLYCLiW6x22IpU3Bn4w45IF0sPJzh24vS/fVUwGZDSm1hXAB0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757276513; c=relaxed/simple; bh=vlFZ+r7s4A6xI2POb9cJbPD9ZVUFBRrUgw4qkRRyFCY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b5TREOwkTMpy9Tr+K1D1oCaCdyEcsAlWZ05J5vXuNOt/FS4fDmVfdP20QTPyfYryEMOO6sCpL9l4761cHQSb3btqX4T2ij+kuZNmVoLdLLxcP2h4RtscpetyWe6v3Xfp1nD2hvWf9Iy34OJsYZAzk4fI2OYAHQXyoEOGNkipNfU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xjafhVbd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xjafhVbd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80E11C4CEF0; Sun, 7 Sep 2025 20:21:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757276512; bh=vlFZ+r7s4A6xI2POb9cJbPD9ZVUFBRrUgw4qkRRyFCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xjafhVbdGfqx0wsDQcxrPQWwJqrHT6K31Jlt/xWcM5n3yw0fnnRs0/MXY6MfXPTCq MjKu0crwQeiF/hZ/c/r50L91X+bSX7wCMbedyiD6iNUEQr+7kCNuu5t1J2sv4nmEY1 mQKuWfdNRhtqLYo3cRqoKXAtshmtMOHuNA3LMOYQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ivan Pravdin , Paul Menzel , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.6 023/121] Bluetooth: vhci: Prevent use-after-free by removing debugfs files early Date: Sun, 7 Sep 2025 21:57:39 +0200 Message-ID: <20250907195610.412520163@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195609.817339617@linuxfoundation.org> References: <20250907195609.817339617@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ivan Pravdin [ Upstream commit 28010791193a4503f054e8d69a950ef815deb539 ] Move the creation of debugfs files into a dedicated function, and ensure they are explicitly removed during vhci_release(), before associated data structures are freed. Previously, debugfs files such as "force_suspend", "force_wakeup", and others were created under hdev->debugfs but not removed in vhci_release(). Since vhci_release() frees the backing vhci_data structure, any access to these files after release would result in use-after-free errors. Although hdev->debugfs is later freed in hci_release_dev(), user can access files after vhci_data is freed but before hdev->debugfs is released. Fixes: ab4e4380d4e1 ("Bluetooth: Add vhci devcoredump support") Signed-off-by: Ivan Pravdin Reviewed-by: Paul Menzel Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- drivers/bluetooth/hci_vhci.c | 57 ++++++++++++++++++++++++++---------- 1 file changed, 41 insertions(+), 16 deletions(-) diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c index 4bfc78f9781ed..0935045051699 100644 --- a/drivers/bluetooth/hci_vhci.c +++ b/drivers/bluetooth/hci_vhci.c @@ -380,6 +380,28 @@ static const struct file_operations force_devcoredump_fops = { .write = force_devcd_write, }; +static void vhci_debugfs_init(struct vhci_data *data) +{ + struct hci_dev *hdev = data->hdev; + + debugfs_create_file("force_suspend", 0644, hdev->debugfs, data, + &force_suspend_fops); + + debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data, + &force_wakeup_fops); + + if (IS_ENABLED(CONFIG_BT_MSFTEXT)) + debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data, + &msft_opcode_fops); + + if (IS_ENABLED(CONFIG_BT_AOSPEXT)) + debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data, + &aosp_capable_fops); + + debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data, + &force_devcoredump_fops); +} + static int __vhci_create_device(struct vhci_data *data, __u8 opcode) { struct hci_dev *hdev; @@ -435,22 +457,8 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode) return -EBUSY; } - debugfs_create_file("force_suspend", 0644, hdev->debugfs, data, - &force_suspend_fops); - - debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data, - &force_wakeup_fops); - - if (IS_ENABLED(CONFIG_BT_MSFTEXT)) - debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data, - &msft_opcode_fops); - - if (IS_ENABLED(CONFIG_BT_AOSPEXT)) - debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data, - &aosp_capable_fops); - - debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data, - &force_devcoredump_fops); + if (!IS_ERR_OR_NULL(hdev->debugfs)) + vhci_debugfs_init(data); hci_skb_pkt_type(skb) = HCI_VENDOR_PKT; @@ -652,6 +660,21 @@ static int vhci_open(struct inode *inode, struct file *file) return 0; } +static void vhci_debugfs_remove(struct hci_dev *hdev) +{ + debugfs_lookup_and_remove("force_suspend", hdev->debugfs); + + debugfs_lookup_and_remove("force_wakeup", hdev->debugfs); + + if (IS_ENABLED(CONFIG_BT_MSFTEXT)) + debugfs_lookup_and_remove("msft_opcode", hdev->debugfs); + + if (IS_ENABLED(CONFIG_BT_AOSPEXT)) + debugfs_lookup_and_remove("aosp_capable", hdev->debugfs); + + debugfs_lookup_and_remove("force_devcoredump", hdev->debugfs); +} + static int vhci_release(struct inode *inode, struct file *file) { struct vhci_data *data = file->private_data; @@ -663,6 +686,8 @@ static int vhci_release(struct inode *inode, struct file *file) hdev = data->hdev; if (hdev) { + if (!IS_ERR_OR_NULL(hdev->debugfs)) + vhci_debugfs_remove(hdev); hci_unregister_dev(hdev); hci_free_dev(hdev); } -- 2.50.1