kernel/linux.git/drivers/bluetooth, branch v6.1.175

Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths

2026-06-01T15:39:34+00:00

commit c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b upstream. Vulnerabilities leading to Use-After-Free (UAF) and Null Pointer Dereference (NPD) conditions were observed in the lifecycle management of hci_uart. The primary issue arises because the workqueues (init_ready and write_work) are only flushed/cancelled if the HCI_UART_PROTO_READY flag is set during TTY close. If a hangup occurs before setup completes, hci_uart_tty_close() skips the teardown of these workqueues and proceeds to free the `hu` struct. When the scheduled work executes later, it blindly dereferences the freed `hu` struct. Furthermore, several data races and UAFs were identified in the teardown sequence: 1. Calling hci_uart_flush() from hci_uart_close() without effectively disabling write_work causes a race condition where both can concurrently double-free hu->tx_skb. This happens because protocol timers can concurrently invoke hci_uart_tx_wakeup() and requeue write_work. 2. Calling hci_free_dev(hdev) before hu->proto->close(hu) causes a UAF when vendor specific protocol close callbacks dereference hu->hdev. 3. In the initialization error paths, failing to take the proto_lock write lock before clearing PROTO_READY leads to races with active readers. Additionally, hci_uart_tty_receive() accesses hu->hdev outside the read lock, leading to UAFs if the initialization error path frees hdev concurrently. Fix these synchronization and lifecycle issues by: 1. Re-ordering hci_uart_tty_close() to clear HCI_UART_PROTO_READY first, followed immediately by a cancel_work_sync(&hu->write_work). Clearing the flag locks out concurrent protocol timers from successfully invoking hci_uart_tx_wakeup(), effectively rendering the cancellation permanent and preventing the tx_skb double-free. 2. Note: Clearing PROTO_READY early causes hci_uart_close() to skip hu->proto->flush(). This is perfectly safe in the tty_close path because hu->proto->close() executes shortly after, which intrinsically purges all protocol SKB queues and tears down the state. 3. Relocating hu->proto->close(hu) strictly prior to hci_free_dev(hdev) across all close and error paths to prevent vendor-level UAFs. 4. Moving the hdev->stat.byte_rx increment in hci_uart_tty_receive() inside the proto_lock read-side critical section to safely synchronize with device unregistration. 5. Adding cancel_work_sync(&hu->write_work) to hci_uart_close() to safely flush the workqueue before hci_uart_flush() is invoked via the HCI core. 6. Utilizing cancel_work_sync() instead of disable_work_sync() across all paths to prevent permanently breaking user-space retry capabilities. Fixes: 3b799254cf6f ("Bluetooth: hci_uart: Cancel init work before unregistering") Cc: stable@vger.kernel.org Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn> Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_ldisc: Clear HCI_UART_PROTO_INIT on error

2026-06-01T15:39:08+00:00

[ Upstream commit 68d39ea5e0adc9ecaea1ce8abd842ec972eb8718 ] When hci_register_dev() fails in hci_uart_register_dev() HCI_UART_PROTO_INIT is not cleared before calling hu->proto->close(hu) and setting hu->hdev to NULL. This means incoming UART data will reach the protocol-specific recv handler in hci_uart_tty_receive() after resources are freed. Clear HCI_UART_PROTO_INIT with a write lock before calling hu->proto->close() and setting hu->hdev to NULL. The write lock ensures all active readers have completed and no new reader can enter the protocol recv path before resources are freed. This allows the protocol-specific recv functions to remove the "HCI_UART_REGISTERED" guard without risking a null pointer dereference if hci_register_dev() fails. Fixes: 5df5dafc171b ("Bluetooth: hci_uart: Fix another race during initialization") Signed-off-by: Jonathan Rissanen Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: virtio_bt: validate rx pkt_type header length

2026-06-01T15:38:55+00:00

commit daf23014e5d975e72ea9c02b5160d3fcf070ea47 upstream. virtbt_rx_handle() reads the leading pkt_type byte from the RX skb and forwards the remainder to hci_recv_frame() for every event/ACL/SCO/ISO type, without checking that the remaining payload is at least the fixed HCI header for that type. After the preceding patch bounds the backend-supplied used.len to [1, VIRTBT_RX_BUF_SIZE], a one-byte completion still reaches hci_recv_frame() with skb->len already pulled to 0. If the byte happened to be HCI_ACLDATA_PKT, the ACL-vs-ISO classification fast-path in hci_dev_classify_pkt_type() dereferences hci_acl_hdr(skb)->handle whenever the HCI device has an active CIS_LINK, BIS_LINK, or PA_LINK connection, reading two bytes of uninitialized RX-buffer data. The same hazard exists for every packet type the driver accepts because none of the switch cases in virtbt_rx_handle() check skb->len against the per-type minimum HCI header size before handing the frame to the core. After stripping pkt_type, require skb->len to cover the fixed header size for the selected type (event 2, ACL 4, SCO 3, ISO 4) before calling hci_recv_frame(); drop ratelimited otherwise. Unknown pkt_type values still take the original kfree_skb() default path. Use bt_dev_err_ratelimited() because both the length and pkt_type values come from an untrusted backend that can otherwise flood the kernel log. Fixes: 160fbcf3bfb9 ("Bluetooth: virtio_bt: Use skb_put to set length") Cc: stable@vger.kernel.org Cc: Soenke Huster Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: virtio_bt: clamp rx length before skb_put

2026-06-01T15:38:55+00:00

commit 21bd244b6de5d2fe1063c23acc93fbdd2b20d112 upstream. virtbt_rx_work() calls skb_put(skb, len) where len comes directly from virtqueue_get_buf() with no validation against the buffer we posted to the device. The RX skb is allocated in virtbt_add_inbuf() and exposed to virtio as exactly 1000 bytes via sg_init_one(). Checking len against skb_tailroom(skb) is not sufficient because alloc_skb() can leave more tailroom than the 1000 bytes actually handed to the device. A malicious or buggy backend can therefore report used.len between 1001 and skb_tailroom(skb), causing skb_put() to include uninitialized kernel heap bytes that were never written by the device. The same path also accepts len == 0, in which case skb_put(skb, 0) leaves the skb empty but virtbt_rx_handle() still reads the pkt_type byte from skb->data, consuming uninitialized memory. Define VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and sg_init_one(), and gate virtbt_rx_work() on that same constant so the bound checked matches the buffer actually exposed to the device. Reject used.len == 0 in the same gate so an empty completion can no longer reach virtbt_rx_handle(). Use bt_dev_err_ratelimited() because the length value comes from an untrusted backend that can otherwise flood the kernel log. Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened the USB 9p transport against unchecked device-reported length. Fixes: 160fbcf3bfb9 ("Bluetooth: virtio_bt: Use skb_put to set length") Cc: stable@vger.kernel.org Cc: Soenke Huster Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: btintel: serialize btintel_hw_error() with hci_req_sync_lock

2026-06-01T15:38:54+00:00

[ Upstream commit 94d8e6fe5d0818e9300e514e095a200bd5ff93ae ] btintel_hw_error() issues two __hci_cmd_sync() calls (HCI_OP_RESET and Intel exception-info retrieval) without holding hci_req_sync_lock(). This lets it race against hci_dev_do_close() -> btintel_shutdown_combined(), which also runs __hci_cmd_sync() under the same lock. When both paths manipulate hdev->req_status/req_rsp concurrently, the close path may free the response skb first, and the still-running hw_error path hits a slab-use-after-free in kfree_skb(). Wrap the whole recovery sequence in hci_req_sync_lock/unlock so it is serialized with every other synchronous HCI command issuer. Below is the data race report and the kasan report: BUG: data-race in __hci_cmd_sync_sk / btintel_shutdown_combined read of hdev->req_rsp at net/bluetooth/hci_sync.c:199 by task kworker/u17:1/83: __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200 __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223 btintel_hw_error+0x114/0x670 drivers/bluetooth/btintel.c:254 hci_error_reset+0x348/0xa30 net/bluetooth/hci_core.c:1030 write/free by task ioctl/22580: btintel_shutdown_combined+0xd0/0x360 drivers/bluetooth/btintel.c:3648 hci_dev_close_sync+0x9ae/0x2c10 net/bluetooth/hci_sync.c:5246 hci_dev_do_close+0x232/0x460 net/bluetooth/hci_core.c:526 BUG: KASAN: slab-use-after-free in sk_skb_reason_drop+0x43/0x380 net/core/skbuff.c:1202 Read of size 4 at addr ffff888144a738dc by task kworker/u17:1/83: __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200 __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223 btintel_hw_error+0x186/0x670 drivers/bluetooth/btintel.c:260 Fixes: 973bb97e5aee ("Bluetooth: btintel: Add generic function for handling hardware errors") Signed-off-by: Cen Zhang Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Fang Wang <32840572@qq.com> Signed-off-by: Sasha Levin

Bluetooth: btusb: clamp SCO altsetting table indices

2026-04-11T12:16:08+00:00

[ Upstream commit 129fa608b6ad08b8ab7178eeb2ec272c993aaccc ] btusb_work() maps the number of active SCO links to USB alternate settings through a three-entry lookup table when CVSD traffic uses transparent voice settings. The lookup currently indexes alts[] with data->sco_num - 1 without first constraining sco_num to the number of available table entries. While the table only defines alternate settings for up to three SCO links, data->sco_num comes from hci_conn_num() and is used directly. Cap the lookup to the last table entry before indexing it so the driver keeps selecting the highest supported alternate setting without reading past alts[]. Fixes: baac6276c0a9 ("Bluetooth: btusb: handle mSBC audio over USB Endpoints") Signed-off-by: Pengpeng Hou Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: hci_ll: Fix firmware leak on error path

2026-04-11T12:16:06+00:00

[ Upstream commit 31148a7be723aa9f2e8fbd62424825ab8d577973 ] Smatch reports: drivers/bluetooth/hci_ll.c:587 download_firmware() warn: 'fw' from request_firmware() not released on lines: 544. In download_firmware(), if request_firmware() succeeds but the returned firmware content is invalid (no data or zero size), the function returns without releasing the firmware, resulting in a resource leak. Fix this by calling release_firmware() before returning when request_firmware() succeeded but the firmware content is invalid. Fixes: 371805522f87 ("bluetooth: hci_uart: add LL protocol serdev driver support") Reviewed-by: Paul Menzel Signed-off-by: Anas Iqbal Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: qca: fix ROM version reading on WCN3998 chips

2026-03-25T10:03:20+00:00

[ Upstream commit 99b2c531e0e797119ae1b9195a8764ee98b00e65 ] WCN3998 uses a bit different format for rom version: [ 5.479978] Bluetooth: hci0: setting up wcn399x [ 5.633763] Bluetooth: hci0: QCA Product ID :0x0000000a [ 5.645350] Bluetooth: hci0: QCA SOC Version :0x40010224 [ 5.650906] Bluetooth: hci0: QCA ROM Version :0x00001001 [ 5.665173] Bluetooth: hci0: QCA Patch Version:0x00006699 [ 5.679356] Bluetooth: hci0: QCA controller version 0x02241001 [ 5.691109] Bluetooth: hci0: QCA Downloading qca/crbtfw21.tlv [ 6.680102] Bluetooth: hci0: QCA Downloading qca/crnv21.bin [ 6.842948] Bluetooth: hci0: QCA setup on UART is completed Fixes: 523760b7ff88 ("Bluetooth: hci_qca: Added support for WCN3998") Reviewed-by: Bartosz Golaszewski Signed-off-by: Dmitry Baryshkov Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: hci_qca: Cleanup on all setup failures

2026-03-04T12:20:40+00:00

[ Upstream commit 5c4e9a8b18457ad28b57069ef0f14661e3192b2e ] The setup process previously combined error handling and retry gating under one condition. As a result, the final failed attempt exited without performing cleanup. Update the failure path to always perform power and port cleanup on setup failure, and reopen the port only when retrying. Fixes: 9e80587aba4c ("Bluetooth: hci_qca: Enhance retry logic in qca_setup") Signed-off-by: Jinwang Li Reviewed-by: Bartosz Golaszewski Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: btusb: Add device ID for Realtek RTL8761BU

2026-03-04T12:20:28+00:00

[ Upstream commit cc6383d4f0cf6127c0552f94cae517a06ccc6b17 ] Add USB device ID 0x2c0a:0x8761 to the btusb driver fo the Realtek RTL8761BU Bluetooth adapter. Reference: https://www.startech.com/en-us/networking-io/av53c1-usb-bluetooth Signed-off-by: Jacopo Scannella Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin