Re: [PATCH] ALSA: line6: fix uninit-value in line6_pod_process_message

[Takashi Iwai <tiwai@xxxxxxx>]

On Tue, 02 Apr 2024 08:47:24 +0200,
Edward Adam Davis wrote:
> 
> [Syzbot reported]
> BUG: KMSAN: uninit-value in line6_pod_process_message+0x72f/0x7b0 sound/usb/line6/pod.c:201
>  line6_pod_process_message+0x72f/0x7b0 sound/usb/line6/pod.c:201
>  line6_data_received+0x5db/0x7e0 sound/usb/line6/driver.c:317
>  __usb_hcd_giveback_urb+0x508/0x770 drivers/usb/core/hcd.c:1648
>  usb_hcd_giveback_urb+0x157/0x720 drivers/usb/core/hcd.c:1732
>  dummy_timer+0xd93/0x6b10 drivers/usb/gadget/udc/dummy_hcd.c:1987
>  call_timer_fn+0x49/0x580 kernel/time/timer.c:1793
>  expire_timers kernel/time/timer.c:1844 [inline]
>  __run_timers kernel/time/timer.c:2418 [inline]
>  __run_timer_base+0x84e/0xe90 kernel/time/timer.c:2429
>  run_timer_base kernel/time/timer.c:2438 [inline]
>  run_timer_softirq+0x3a/0x70 kernel/time/timer.c:2448
>  __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554
>  invoke_softirq kernel/softirq.c:428 [inline]
>  __irq_exit_rcu kernel/softirq.c:633 [inline]
>  irq_exit_rcu+0x6a/0x130 kernel/softirq.c:645
>  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
>  sysvec_apic_timer_interrupt+0x83/0x90 arch/x86/kernel/apic/apic.c:1043
>  asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
>  native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
>  arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
>  acpi_safe_halt+0x25/0x30 drivers/acpi/processor_idle.c:112
>  acpi_idle_do_entry+0x22/0x40 drivers/acpi/processor_idle.c:573
>  acpi_idle_enter+0xa1/0xc0 drivers/acpi/processor_idle.c:707
>  cpuidle_enter_state+0xcb/0x250 drivers/cpuidle/cpuidle.c:267
>  cpuidle_enter+0x7f/0xf0 drivers/cpuidle/cpuidle.c:388
>  call_cpuidle kernel/sched/idle.c:155 [inline]
>  cpuidle_idle_call kernel/sched/idle.c:236 [inline]
>  do_idle+0x551/0x750 kernel/sched/idle.c:332
>  cpu_startup_entry+0x65/0x80 kernel/sched/idle.c:430
>  rest_init+0x1e8/0x260 init/main.c:732
>  start_kernel+0x927/0xa70 init/main.c:1074
>  x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:507
>  x86_64_start_kernel+0x98/0xa0 arch/x86/kernel/head64.c:488
>  common_startup_64+0x12c/0x137
> 
> Uninit was created at:
>  slab_post_alloc_hook mm/slub.c:3804 [inline]
>  slab_alloc_node mm/slub.c:3845 [inline]
>  kmalloc_trace+0x578/0xba0 mm/slub.c:3992
>  kmalloc include/linux/slab.h:628 [inline]
>  line6_init_cap_control+0x4f1/0x770 sound/usb/line6/driver.c:700
>  line6_probe+0xeae/0x1120 sound/usb/line6/driver.c:797
>  pod_probe+0x79/0x90 sound/usb/line6/pod.c:522
>  usb_probe_interface+0xd6f/0x1350 drivers/usb/core/driver.c:399
>  really_probe+0x4db/0xd90 drivers/base/dd.c:656
>  __driver_probe_device+0x2ab/0x5d0 drivers/base/dd.c:798
>  driver_probe_device+0x72/0x890 drivers/base/dd.c:828
>  __device_attach_driver+0x568/0x9e0 drivers/base/dd.c:956
>  bus_for_each_drv+0x403/0x620 drivers/base/bus.c:457
>  __device_attach+0x3c1/0x650 drivers/base/dd.c:1028
>  device_initial_probe+0x32/0x40 drivers/base/dd.c:1077
>  bus_probe_device+0x3dc/0x5c0 drivers/base/bus.c:532
>  device_add+0x1475/0x1c90 drivers/base/core.c:3705
>  usb_set_configuration+0x31c9/0x38d0 drivers/usb/core/message.c:2210
>  usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:254
>  usb_probe_device+0x3a7/0x690 drivers/usb/core/driver.c:294
>  really_probe+0x4db/0xd90 drivers/base/dd.c:656
>  __driver_probe_device+0x2ab/0x5d0 drivers/base/dd.c:798
>  driver_probe_device+0x72/0x890 drivers/base/dd.c:828
>  __device_attach_driver+0x568/0x9e0 drivers/base/dd.c:956
>  bus_for_each_drv+0x403/0x620 drivers/base/bus.c:457
>  __device_attach+0x3c1/0x650 drivers/base/dd.c:1028
>  device_initial_probe+0x32/0x40 drivers/base/dd.c:1077
>  bus_probe_device+0x3dc/0x5c0 drivers/base/bus.c:532
>  device_add+0x1475/0x1c90 drivers/base/core.c:3705
>  usb_new_device+0x15ff/0x2470 drivers/usb/core/hub.c:2643
>  hub_port_connect drivers/usb/core/hub.c:5512 [inline]
>  hub_port_connect_change drivers/usb/core/hub.c:5652 [inline]
>  port_event drivers/usb/core/hub.c:5812 [inline]
>  hub_event+0x4ff8/0x72d0 drivers/usb/core/hub.c:5894
>  process_one_work kernel/workqueue.c:3254 [inline]
>  process_scheduled_works+0xa81/0x1bd0 kernel/workqueue.c:3335
>  worker_thread+0xea5/0x1560 kernel/workqueue.c:3416
>  kthread+0x3e2/0x540 kernel/kthread.c:388
>  ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
> [Fix]
> Let's clear all the content of the buffer message during alloc.
> 
> Reported-and-tested-by: syzbot+7fb05ccf7b3d2f9617b3@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>

A fix already submitted in https://lore.kernel.org/r/20240402063628.26609-1-tiwai@xxxxxxx


thanks,

Takashi