From eddfe9672ed2392b8abe782d40abdf1982d8943f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 11 Apr 2019 19:58:32 +0200 Subject: [PATCH] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" [ Upstream commit f0654ba94e33699b295ce4f3dc73094db6209035 ] This reverts commit feb689025fbb6f0aa6297d3ddf97de945ea4ad32. The fix attempt was incorrect, leading to the mutex deadlock through the close of OSS sequencer client. The proper fix needs more consideration, so let's revert it now. Fixes: feb689025fbb ("ALSA: seq: Protect in-kernel ioctl calls with mutex") Reported-by: syzbot+47ded6c0f23016cde310@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/seq/seq_clientmgr.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 37312a3ae60f..f59e13c1d84a 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -2337,19 +2337,14 @@ int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg) { const struct ioctl_handler *handler; struct snd_seq_client *client; - int err; client = clientptr(clientid); if (client == NULL) return -ENXIO; for (handler = ioctl_handlers; handler->cmd > 0; ++handler) { - if (handler->cmd == cmd) { - mutex_lock(&client->ioctl_mutex); - err = handler->func(client, arg); - mutex_unlock(&client->ioctl_mutex); - return err; - } + if (handler->cmd == cmd) + return handler->func(client, arg); } pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",