kernel/linux.git/drivers/bluetooth, branch v5.10.258

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

2026-06-01T15:29:51+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

2026-06-01T15:29:31+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: btusb: clamp SCO altsetting table indices

2026-04-18T08:31:05+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

2026-04-18T08:31:04+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: btusb: Add device ID for Realtek RTL8761BU

2026-03-04T12:20:02+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

Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work

2026-02-06T15:40:10+00:00

[ Upstream commit 0c3cd7a0b862c37acbee6d9502107146cc944398 ] hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling hci_uart_register_dev(), which calls proto->open() to initialize hu->priv. However, if a TTY write wakeup occurs during this window, hci_uart_tx_wakeup() may schedule write_work before hu->priv is initialized, leading to a NULL pointer dereference in hci_uart_write_work() when proto->dequeue() accesses hu->priv. The race condition is: CPU0 CPU1 ---- ---- hci_uart_set_proto() set_bit(HCI_UART_PROTO_INIT) hci_uart_register_dev() tty write wakeup hci_uart_tty_wakeup() hci_uart_tx_wakeup() schedule_work(&hu->write_work) proto->open(hu) // initializes hu->priv hci_uart_write_work() hci_uart_dequeue() proto->dequeue(hu) // accesses hu->priv (NULL!) Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open() succeeds, ensuring hu->priv is initialized before any work can be scheduled. Fixes: 5df5dafc171b ("Bluetooth: hci_uart: Fix another race during initialization") Link: https://lore.kernel.org/linux-bluetooth/6969764f.170a0220.2b9fc4.35a7@mx.google.com/ Signed-off-by: Jia-Hong Su Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: btusb: Add new VID/PID 13d3/3533 for RTL8821CE

2026-01-19T12:11:41+00:00

[ Upstream commit 525459da4bd62a81142fea3f3d52188ceb4d8907 ] Add VID 13d3 & PID 3533 for Realtek RTL8821CE USB Bluetooth chip. The information in /sys/kernel/debug/usb/devices about the Bluetooth device is listed as the below. T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0 D: Ver= 1.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=13d3 ProdID=3533 Rev= 1.10 S: Manufacturer=Realtek S: Product=Bluetooth Radio S: SerialNumber=00e04c000001 C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=500mA I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=1ms E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 0 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 0 Ivl=1ms I: If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 9 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 9 Ivl=1ms I: If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 17 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 17 Ivl=1ms I: If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 25 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 25 Ivl=1ms I: If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 33 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 33 Ivl=1ms I: If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 49 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 49 Ivl=1ms Signed-off-by: Gongwei Li Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: btusb: reorder cleanup in btusb_disconnect to avoid UAF

2025-12-06T21:08:17+00:00

[ Upstream commit 23d22f2f71768034d6ef86168213843fc49bf550 ] There is a KASAN: slab-use-after-free read in btusb_disconnect(). Calling "usb_driver_release_interface(&btusb_driver, data->intf)" will free the btusb data associated with the interface. The same data is then used later in the function, hence the UAF. Fix by moving the accesses to btusb data to before the data is free'd. Reported-by: syzbot+2fc81b50a4f8263a159b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2fc81b50a4f8263a159b Tested-by: syzbot+2fc81b50a4f8263a159b@syzkaller.appspotmail.com Fixes: fd913ef7ce619 ("Bluetooth: btusb: Add out-of-band wakeup support") Signed-off-by: Raphael Pinsonneault-Thibeault Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: bcsp: receive data only if registered

2025-12-06T21:08:15+00:00

[ Upstream commit ca94b2b036c22556c3a66f1b80f490882deef7a6 ] Currently, bcsp_recv() can be called even when the BCSP protocol has not been registered. This leads to a NULL pointer dereference, as shown in the following stack trace: KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:bcsp_recv+0x13d/0x1740 drivers/bluetooth/hci_bcsp.c:590 Call Trace: hci_uart_tty_receive+0x194/0x220 drivers/bluetooth/hci_ldisc.c:627 tiocsti+0x23c/0x2c0 drivers/tty/tty_io.c:2290 tty_ioctl+0x626/0xde0 drivers/tty/tty_io.c:2706 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f To prevent this, ensure that the HCI_UART_REGISTERED flag is set before processing received data. If the protocol is not registered, return -EUNATCH. Reported-by: syzbot+4ed6852d4da4606c93da@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4ed6852d4da4606c93da Tested-by: syzbot+4ed6852d4da4606c93da@syzkaller.appspotmail.com Signed-off-by: Ivan Pravdin Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: btrtl: Prevent potential NULL dereference

2025-05-02T05:40:59+00:00

[ Upstream commit 324dddea321078a6eeb535c2bff5257be74c9799 ] The btrtl_initialize() function checks that rtl_load_file() either had an error or it loaded a zero length file. However, if it loaded a zero length file then the error code is not set correctly. It results in an error pointer vs NULL bug, followed by a NULL pointer dereference. This was detected by Smatch: drivers/bluetooth/btrtl.c:592 btrtl_initialize() warn: passing zero to 'ERR_PTR' Fixes: 26503ad25de8 ("Bluetooth: btrtl: split the device initialization into smaller parts") Signed-off-by: Dan Carpenter Reviewed-by: Hans de Goede Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin