[PATCH 4.14 18/29] ALSA: seq: Use bool for snd_seq_queue internal flags

Greg Kroah-Hartman
2021-01-07T14:32:09Z

From: Takashi Iwai <tiwai@suse.de>

commit 4ebd47037027c4beae99680bff3b20fdee5d7c1e upstream.

The snd_seq_queue struct contains various flags in the bit fields.
Those are categorized to two different use cases, both of which are
protected by different spinlocks. That implies that there are still
potential risks of the bad operations for bit fields by concurrent
accesses.

For addressing the problem, this patch rearranges those flags to be
a standard bool instead of a bit field.

Reported-by: syzbot+63cbe31877bb80ef58f5@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20201206083456.21110-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/core/seq/seq_queue.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/sound/core/seq/seq_queue.h
+++ b/sound/core/seq/seq_queue.h
@@ -40,10 +40,10 @@ struct snd_seq_queue {

struct snd_seq_timer *timer; /* time keeper for this queue */
int owner; /* client that 'owns' the timer */
- unsigned int locked:1, /* timer is only accesibble by owner if set */
- klocked:1, /* kernel lock (after START) */
- check_again:1,
- check_blocked:1;
+ bool locked; /* timer is only accesibble by owner if set */
+ bool klocked; /* kernel lock (after START) */
+ bool check_again; /* concurrent access happened during check */
+ bool check_blocked; /* queue being checked */

unsigned int flags; /* status flags */
unsigned int info_flags; /* info for sync */