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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2021-01-11 14:02:50 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-01-12 14:57:29 +0100 |
| commit | e7c22eeaff8565d9a8374f320238c251ca31480b (patch) | |
| tree | e6e4fa08c235fd927ac0faa8de70e35889a35ca8 /sound | |
| parent | 615d435400435876ac68c1de37e9526a9164eaec (diff) | |
| download | lwn-e7c22eeaff8565d9a8374f320238c251ca31480b.tar.gz lwn-e7c22eeaff8565d9a8374f320238c251ca31480b.zip | |
ALSA: fireface: Fix integer overflow in transmit_midi_msg()
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 <o-takashi@sakamocchi.jp>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210111130251.361335-2-geert+renesas@glider.be
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/firewire/fireface/ff-transaction.c | 2 |
1 files changed, 1 insertions, 1 deletions
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; |