Commit c7d58971 authored by Kees Cook's avatar Kees Cook Committed by Takashi Iwai
Browse files

ALSA: mixart: Reduce size of mixart_timer_notify 



The mixart_timer_notify structure was larger than could be represented
by the mixart_msg_data array storage. Adjust the size to as large as
possible to fix the warning seen with -Warray-bounds builds:

sound/pci/mixart/mixart_core.c: In function 'snd_mixart_threaded_irq':
sound/pci/mixart/mixart_core.c:447:50: error: array subscript 'struct mixart_timer_notify[0]' is partly outside array bounds of 'u32[128]' {aka 'unsigned int[128]'} [-Werror=array-bounds]
  447 |                                 for(i=0; i<notify->stream_count; i++) {
      |                                                  ^~
sound/pci/mixart/mixart_core.c:328:12: note: while referencing 'mixart_msg_data'
  328 | static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
      |            ^~~~~~~~~~~~~~~

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211207062941.2413679-1-keescook@chromium.org


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 86a9bb5b

sound/pci/mixart/mixart_core.c

+1 −2
Original line number Diff line number Diff line
@@ -23,8 +23,6 @@ 
#define MSG_DESCRIPTOR_SIZE         0x24

#define MSG_HEADER_SIZE             (MSG_DESCRIPTOR_SIZE + 4)



#define MSG_DEFAULT_SIZE            512



#define MSG_TYPE_MASK               0x00000003    /* mask for following types */

#define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */

#define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
@@ -444,6 +442,7 @@ irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id) 
				struct mixart_timer_notify *notify;

				notify = (struct mixart_timer_notify *)mixart_msg_data;



				BUILD_BUG_ON(sizeof(notify) > sizeof(mixart_msg_data));

				for(i=0; i<notify->stream_count; i++) {



					u32 buffer_id = notify->streams[i].buffer_id;

sound/pci/mixart/mixart_core.h

+9 −1
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ enum mixart_message_id { 
	MSG_CLOCK_SET_PROPERTIES             = 0x200002,

};



#define MSG_DEFAULT_SIZE            512



struct mixart_msg

{
@@ -251,10 +252,17 @@ struct mixart_sample_pos 
	u32   sample_pos_low_part;

} __attribute__((packed));



/*

 * This structure is limited by the size of MSG_DEFAULT_SIZE. Instead of

 * having MIXART_MAX_STREAM_PER_CARD * MIXART_MAX_CARDS many streams,

 * this is capped to have a total size below MSG_DEFAULT_SIZE.

 */

#define MIXART_MAX_TIMER_NOTIFY_STREAMS				\

	((MSG_DEFAULT_SIZE - sizeof(u32)) / sizeof(struct mixart_sample_pos))

struct mixart_timer_notify

{

	u32                  stream_count;

	struct mixart_sample_pos  streams[MIXART_MAX_STREAM_PER_CARD * MIXART_MAX_CARDS];

	struct mixart_sample_pos  streams[MIXART_MAX_TIMER_NOTIFY_STREAMS];

} __attribute__((packed));