On 29/12/2022 11:28, Krzysztof Kozlowski wrote:
> The driver shutdown callback (which sends EDL_SOC_RESET to the device
> over serdev) should not be invoked when HCI device is not open (e.g. if
> hci_dev_open_sync() failed), because the serdev and its TTY are not open
> either. Also skip this step if device is powered off
> (qca_power_shutdown()).
>
> The shutdown callback causes use-after-free during system reboot with
> Qualcomm Atheros Bluetooth:
>
> Unable to handle kernel paging request at virtual address 0072662f67726fd7
> ...
> CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W 6.1.0-rt5-00325-g8a5f56bcfcca #8
> Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
> Call trace:
> tty_driver_flush_buffer+0x4/0x30
> serdev_device_write_flush+0x24/0x34
> qca_serdev_shutdown+0x80/0x130 [hci_uart]
> device_shutdown+0x15c/0x260
> kernel_restart+0x48/0xac
>
> KASAN report:
>
> BUG: KASAN: use-after-free in tty_driver_flush_buffer+0x1c/0x50
> Read of size 8 at addr ffff16270c2e0018 by task systemd-shutdow/1
>
> CPU: 7 PID: 1 Comm: systemd-shutdow Not tainted 6.1.0-next-20221220-00014-gb85aaf97fb01-dirty #28
> Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
> Call trace:
> dump_backtrace.part.0+0xdc/0xf0
> show_stack+0x18/0x30
> dump_stack_lvl+0x68/0x84
> print_report+0x188/0x488
> kasan_report+0xa4/0xf0
> __asan_load8+0x80/0xac
> tty_driver_flush_buffer+0x1c/0x50
> ttyport_write_flush+0x34/0x44
> serdev_device_write_flush+0x48/0x60
> qca_serdev_shutdown+0x124/0x274
> device_shutdown+0x1e8/0x350
> kernel_restart+0x48/0xb0
> __do_sys_reboot+0x244/0x2d0
> __arm64_sys_reboot+0x54/0x70
> invoke_syscall+0x60/0x190
> el0_svc_common.constprop.0+0x7c/0x160
> do_el0_svc+0x44/0xf0
> el0_svc+0x2c/0x6c
> el0t_64_sync_handler+0xbc/0x140
> el0t_64_sync+0x190/0x194
>
> Fixes: 7e7bbddd029b ("Bluetooth: hci_qca: Fix qca6390 enable failure after warm reboot")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
>
> ---
Any comments on this? Patchwork tools complain on longer line, but
without it checkpatch would complain as well, so I assume you do not
expect to fix it?
Best regards,
Krzysztof
