From 68e67535e26b29e50e6f97cd27c36b85e2631c13 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 11 Jan 2021 14:02:50 +0100 Subject: [PATCH] ALSA: fireface: Fix integer overflow in transmit_midi_msg() commit e7c22eeaff8565d9a8374f320238c251ca31480b upstream. As snd_ff.rx_bytes[] is unsigned int, and NSEC_PER_SEC is 1000000000L, the second multiplication in ff->rx_bytes[port] * 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 ff->rx_bytes[port] <= 16777. Fixes: 19174295788de77d ("ALSA: fireface: add transaction support") Reviewed-by: Takashi Sakamoto Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20210111130251.361335-2-geert+renesas@glider.be Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/firewire/fireface/ff-transaction.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/firewire/fireface/ff-transaction.c b/sound/firewire/fireface/ff-transaction.c index 7f82762ccc8c..ee7122c461d4 100644 --- a/sound/firewire/fireface/ff-transaction.c +++ b/sound/firewire/fireface/ff-transaction.c @@ -88,7 +88,7 @@ static void transmit_midi_msg(struct snd_ff *ff, unsigned int port) /* Set interval to next transaction. */ ff->next_ktime[port] = ktime_add_ns(ktime_get(), - ff->rx_bytes[port] * 8 * NSEC_PER_SEC / 31250); + ff->rx_bytes[port] * 8 * (NSEC_PER_SEC / 31250)); if (quad_count == 1) tcode = TCODE_WRITE_QUADLET_REQUEST;