About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btrtl: fix out of bounds memory access

The problem is detected by KASAN. btrtl driver uses private hci data to store ‘struct btrealtek_data’. If btrtl driver is used with btusb, then memory for private hci data is allocated in btusb. But no private data is allocated after hci_dev, when btrtl is used with hci_h5.

This commit adds memory allocation for hci_h5 case.

================================================================== BUG: KASAN: slab-out-of-bounds in btrtl_initialize+0x6cc/0x958 [btrtl] Write of size 8 at addr ffff00000f5a5748 by task kworker/u9:0/76

Hardware name: Pine64 PinePhone (1.2) (DT) Workqueue: hci0 hci_power_on [bluetooth] Call trace: dump_backtrace+0x9c/0x128 show_stack+0x20/0x38 dump_stack_lvl+0x48/0x60 print_report+0xf8/0x5d8 kasan_report+0x90/0xd0 __asan_store8+0x9c/0xc0 [btrtl] h5_btrtl_setup+0xd0/0x2f8 [hci_uart] h5_setup+0x50/0x80 [hci_uart] hci_uart_setup+0xd4/0x260 [hci_uart] hci_dev_open_sync+0x1cc/0xf68 [bluetooth] hci_dev_do_open+0x34/0x90 [bluetooth] hci_power_on+0xc4/0x3c8 [bluetooth] process_one_work+0x328/0x6f0 worker_thread+0x410/0x778 kthread+0x168/0x178 ret_from_fork+0x10/0x20

Allocated by task 53: kasan_save_stack+0x3c/0x68 kasan_save_track+0x20/0x40 kasan_save_alloc_info+0x68/0x78 __kasan_kmalloc+0xd4/0xd8 __kmalloc+0x1b4/0x3b0 hci_alloc_dev_priv+0x28/0xa58 [bluetooth] hci_uart_register_device+0x118/0x4f8 [hci_uart] h5_serdev_probe+0xf4/0x178 [hci_uart] serdev_drv_probe+0x54/0xa0 really_probe+0x254/0x588 __driver_probe_device+0xc4/0x210 driver_probe_device+0x64/0x160 __driver_attach_async_helper+0x88/0x158 async_run_entry_fn+0xd0/0x388 process_one_work+0x328/0x6f0 worker_thread+0x410/0x778 kthread+0x168/0x178 ret_from_fork+0x10/0x20

Last potentially related work creation: kasan_save_stack+0x3c/0x68 __kasan_record_aux_stack+0xb0/0x150 kasan_record_aux_stack_noalloc+0x14/0x20 __queue_work+0x33c/0x960 queue_work_on+0x98/0xc0 hci_recv_frame+0xc8/0x1e8 [bluetooth] h5_complete_rx_pkt+0x2c8/0x800 [hci_uart] h5_rx_payload+0x98/0xb8 [hci_uart] h5_recv+0x158/0x3d8 [hci_uart] hci_uart_receive_buf+0xa0/0xe8 [hci_uart] ttyport_receive_buf+0xac/0x178 flush_to_ldisc+0x130/0x2c8 process_one_work+0x328/0x6f0 worker_thread+0x410/0x778 kthread+0x168/0x178 ret_from_fork+0x10/0x20

Second to last potentially related work creation: kasan_save_stack+0x3c/0x68 __kasan_record_aux_stack+0xb0/0x150 kasan_record_aux_stack_noalloc+0x14/0x20 __queue_work+0x788/0x960 queue_work_on+0x98/0xc0 __hci_cmd_sync_sk+0x23c/0x7a0 [bluetooth] __hci_cmd_sync+0x24/0x38 [bluetooth] btrtl_initialize+0x760/0x958 [btrtl] h5_btrtl_setup+0xd0/0x2f8 [hci_uart] h5_setup+0x50/0x80 [hci_uart] hci_uart_setup+0xd4/0x260 [hci_uart] hci_dev_open_sync+0x1cc/0xf68 [bluetooth] hci_dev_do_open+0x34/0x90 [bluetooth] hci_power_on+0xc4/0x3c8 [bluetooth] process_one_work+0x328/0x6f0 worker_thread+0x410/0x778 kthread+0x168/0x178 ret_from_fork+0x10/0x20

Affected product:

AlmaLinux 9.2 ESU , TuxCare 9.6 ESU

Affected packages:

kernel @ 5.14.0-11 (+2 more)

Live-patch status from KernelCare for each operating system.