Unverified Commit a8b5d6a5 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!14992 ALSA: seq: oss: Fix races at processing SysEx messages 

Merge Pull Request from: @ci-robot 
 
PR sync from: Gu Bowen <gubowen5@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/YAO7UDGTOOSJIRKRLSG5726H7SOF6QNU/ 
 
https://gitee.com/src-openeuler/kernel/issues/IBID2T 
 
Link:https://gitee.com/openeuler/kernel/pulls/14992

 

Reviewed-by: default avatarYuan Can <yuancan@huawei.com>
Signed-off-by: default avatarYuan Can <yuancan@huawei.com>
parents dfeabfab 36c6f4a6

sound/core/seq/oss/seq_oss_synth.c

+17 −6
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ static struct seq_oss_synth midi_synth_dev = { 
};



static DEFINE_SPINLOCK(register_lock);

static DEFINE_MUTEX(sysex_mutex);



/*

 * prototypes
@@ -504,16 +505,20 @@ snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, 
	unsigned char *dest;

	struct seq_oss_synth_sysex *sysex;

	struct seq_oss_synthinfo *info;

	int err = -EINVAL;



	info = snd_seq_oss_synth_info(dp, dev);

	if (!info)

		return -ENXIO;



	mutex_lock(&sysex_mutex);

	sysex = info->sysex;

	if (sysex == NULL) {

		sysex = kzalloc(sizeof(*sysex), GFP_KERNEL);

		if (sysex == NULL)

			return -ENOMEM;

		if (sysex == NULL) {

			err = -ENOMEM;

			goto unlock_sysex;

		}

		info->sysex = sysex;

	}
@@ -538,19 +543,25 @@ snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, 
		if (sysex->skip) {

			sysex->skip = 0;

			sysex->len = 0;

			return -EINVAL; /* skip */

			err = -EINVAL; /* skip */

			goto unlock_sysex;

		}

		/* copy the data to event record and send it */

		ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;

		if (snd_seq_oss_synth_addr(dp, dev, ev))

			return -EINVAL;

		if (snd_seq_oss_synth_addr(dp, dev, ev)) {

			err = -EINVAL;

			goto unlock_sysex;

		}

		ev->data.ext.len = sysex->len;

		ev->data.ext.ptr = sysex->buf;

		sysex->len = 0;

		mutex_unlock(&sysex_mutex);

		return 0;

	}



	return -EINVAL; /* skip */

unlock_sysex:

	mutex_unlock(&sysex_mutex);

	return err; /* skip */

}



/*