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authorGeert Uytterhoeven <geert+renesas@glider.be>2021-01-11 14:02:51 +0100
committerTakashi Iwai <tiwai@suse.de>2021-01-12 14:57:38 +0100
commit9f65df9c589f249435255da37a5dd11f1bc86f4d (patch)
tree150f891757378000ecd6e2b281c0e5932e10558b /sound/firewire/tascam
parente7c22eeaff8565d9a8374f320238c251ca31480b (diff)
downloadlinux-9f65df9c589f249435255da37a5dd11f1bc86f4d.tar.gz
ALSA: firewire-tascam: Fix integer overflow in midi_port_work()
As snd_fw_async_midi_port.consume_bytes is unsigned int, and
NSEC_PER_SEC is 1000000000L, the second multiplication in

    port->consume_bytes * 8 * NSEC_PER_SEC / 31250

always overflows on 32-bit platforms, truncating the result.  Fix this
by precalculating "NSEC_PER_SEC / 31250", which is an integer constant.

Note that this assumes port->consume_bytes <= 16777.

Fixes: 531f471834227d03 ("ALSA: firewire-lib/firewire-tascam: localize async midi port")
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210111130251.361335-3-geert+renesas@glider.be
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire/tascam')
-rw-r--r--sound/firewire/tascam/tascam-transaction.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/firewire/tascam/tascam-transaction.c b/sound/firewire/tascam/tascam-transaction.c
index 90288b4b4637..a073cece4a7d 100644
--- a/sound/firewire/tascam/tascam-transaction.c
+++ b/sound/firewire/tascam/tascam-transaction.c
@@ -209,7 +209,7 @@ static void midi_port_work(struct work_struct *work)
 
 	/* Set interval to next transaction. */
 	port->next_ktime = ktime_add_ns(ktime_get(),
-				port->consume_bytes * 8 * NSEC_PER_SEC / 31250);
+			port->consume_bytes * 8 * (NSEC_PER_SEC / 31250));
 
 	/* Start this transaction. */
 	port->idling = false;