Commit ac0d71ee authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: ump: Don't accept an invalid UMP protocol number 

When a UMP Stream Configuration message is received, the driver tries
to switch the protocol, but there was no sanity check of the protocol,
hence it can pass an invalid value.  Add the check and bail out if a
wrong value is passed.

Fixes: a7980768 ("ALSA: ump: Add helper to change MIDI protocol")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20240529164723.18309-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 6d40dbc7

sound/core/ump.c

+7 −0
Original line number Diff line number Diff line
@@ -685,10 +685,17 @@ static void seq_notify_protocol(struct snd_ump_endpoint *ump) 
 */

int snd_ump_switch_protocol(struct snd_ump_endpoint *ump, unsigned int protocol)

{

	unsigned int type;



	protocol &= ump->info.protocol_caps;

	if (protocol == ump->info.protocol)

		return 0;



	type = protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI_MASK;

	if (type != SNDRV_UMP_EP_INFO_PROTO_MIDI1 &&

	    type != SNDRV_UMP_EP_INFO_PROTO_MIDI2)

		return 0;



	ump->info.protocol = protocol;

	ump_dbg(ump, "New protocol = %x (caps = %x)\n",

		protocol, ump->info.protocol_caps);