linux/sound/usb/mixer.h
Takashi Iwai 124751d5e6 ALSA: usb-audio: Kill stray URB at exiting
USB-audio driver may leave a stray URB for the mixer interrupt when it
exits by some error during probe.  This leads to a use-after-free
error as spotted by syzkaller like:
  ==================================================================
  BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:16
   dump_stack+0x292/0x395 lib/dump_stack.c:52
   print_address_description+0x78/0x280 mm/kasan/report.c:252
   kasan_report_error mm/kasan/report.c:351
   kasan_report+0x23d/0x350 mm/kasan/report.c:409
   __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430
   snd_usb_mixer_interrupt+0x604/0x6f0 sound/usb/mixer.c:2490
   __usb_hcd_giveback_urb+0x2e0/0x650 drivers/usb/core/hcd.c:1779
   ....

  Allocated by task 1484:
   save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
   save_stack+0x43/0xd0 mm/kasan/kasan.c:447
   set_track mm/kasan/kasan.c:459
   kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
   kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772
   kmalloc ./include/linux/slab.h:493
   kzalloc ./include/linux/slab.h:666
   snd_usb_create_mixer+0x145/0x1010 sound/usb/mixer.c:2540
   create_standard_mixer_quirk+0x58/0x80 sound/usb/quirks.c:516
   snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560
   create_composite_quirk+0x1c4/0x3e0 sound/usb/quirks.c:59
   snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560
   usb_audio_probe+0x1040/0x2c10 sound/usb/card.c:618
   ....

  Freed by task 1484:
   save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
   save_stack+0x43/0xd0 mm/kasan/kasan.c:447
   set_track mm/kasan/kasan.c:459
   kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524
   slab_free_hook mm/slub.c:1390
   slab_free_freelist_hook mm/slub.c:1412
   slab_free mm/slub.c:2988
   kfree+0xf6/0x2f0 mm/slub.c:3919
   snd_usb_mixer_free+0x11a/0x160 sound/usb/mixer.c:2244
   snd_usb_mixer_dev_free+0x36/0x50 sound/usb/mixer.c:2250
   __snd_device_free+0x1ff/0x380 sound/core/device.c:91
   snd_device_free_all+0x8f/0xe0 sound/core/device.c:244
   snd_card_do_free sound/core/init.c:461
   release_card_device+0x47/0x170 sound/core/init.c:181
   device_release+0x13f/0x210 drivers/base/core.c:814
   ....

Actually such a URB is killed properly at disconnection when the
device gets probed successfully, and what we need is to apply it for
the error-path, too.

In this patch, we apply snd_usb_mixer_disconnect() at releasing.
Also introduce a new flag, disconnected, to struct usb_mixer_interface
for not performing the disconnection procedure twice.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-10 14:17:09 +02:00

106 lines
2.9 KiB
C

#ifndef __USBMIXER_H
#define __USBMIXER_H
#include <sound/info.h>
struct usb_mixer_interface {
struct snd_usb_audio *chip;
struct usb_host_interface *hostif;
struct list_head list;
unsigned int ignore_ctl_error;
struct urb *urb;
/* array[MAX_ID_ELEMS], indexed by unit id */
struct usb_mixer_elem_list **id_elems;
/* the usb audio specification version this interface complies to */
int protocol;
/* Sound Blaster remote control stuff */
const struct rc_config *rc_cfg;
u32 rc_code;
wait_queue_head_t rc_waitq;
struct urb *rc_urb;
struct usb_ctrlrequest *rc_setup_packet;
u8 rc_buffer[6];
bool disconnected;
};
#define MAX_CHANNELS 16 /* max logical channels */
enum {
USB_MIXER_BOOLEAN,
USB_MIXER_INV_BOOLEAN,
USB_MIXER_S8,
USB_MIXER_U8,
USB_MIXER_S16,
USB_MIXER_U16,
USB_MIXER_S32,
USB_MIXER_U32,
};
typedef void (*usb_mixer_elem_dump_func_t)(struct snd_info_buffer *buffer,
struct usb_mixer_elem_list *list);
typedef int (*usb_mixer_elem_resume_func_t)(struct usb_mixer_elem_list *elem);
struct usb_mixer_elem_list {
struct usb_mixer_interface *mixer;
struct usb_mixer_elem_list *next_id_elem; /* list of controls with same id */
struct snd_kcontrol *kctl;
unsigned int id;
usb_mixer_elem_dump_func_t dump;
usb_mixer_elem_resume_func_t resume;
};
struct usb_mixer_elem_info {
struct usb_mixer_elem_list head;
unsigned int control; /* CS or ICN (high byte) */
unsigned int cmask; /* channel mask bitmap: 0 = master */
unsigned int idx_off; /* Control index offset */
unsigned int ch_readonly;
unsigned int master_readonly;
int channels;
int val_type;
int min, max, res;
int dBmin, dBmax;
int cached;
int cache_val[MAX_CHANNELS];
u8 initialized;
u8 min_mute;
void *private_data;
};
int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
int ignore_error);
void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer);
void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid);
int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
int request, int validx, int value_set);
int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list,
struct snd_kcontrol *kctl);
void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list,
struct usb_mixer_interface *mixer,
int unitid);
int snd_usb_mixer_vol_tlv(struct snd_kcontrol *kcontrol, int op_flag,
unsigned int size, unsigned int __user *_tlv);
#ifdef CONFIG_PM
int snd_usb_mixer_suspend(struct usb_mixer_interface *mixer);
int snd_usb_mixer_resume(struct usb_mixer_interface *mixer, bool reset_resume);
#endif
int snd_usb_set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
int index, int value);
int snd_usb_get_cur_mix_value(struct usb_mixer_elem_info *cval,
int channel, int index, int *value);
extern void snd_usb_mixer_elem_free(struct snd_kcontrol *kctl);
#endif /* __USBMIXER_H */