ALSA: rawmidi - fix the uninitalized user_pversion

commit 39a8fc4971a00d22536aeb7d446ee4a97810611b upstream.

The user_pversion was uninitialized for the user space file structure
in the open function, because the file private structure use
kmalloc for the allocation.

The kernel ALSA sequencer code clears the file structure, so no additional
fixes are required.

Cc: stable@kernel.org
Cc: broonie@kernel.org
BugLink: https://github.com/alsa-project/alsa-lib/issues/178
Fixes: 09d23174402d ("ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION")
Reported-by: syzbot+88412ee8811832b00dbe@syzkaller.appspotmail.com
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20211218123925.2583847-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 6f30231bdb88454c0d6c279f557965c1083608c4..befa9809ff001ec514a0512d560ce079041d86cc 100644 (file)
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -447,6 +447,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
                err = -ENOMEM;
                goto __error;
        }
+       rawmidi_file->user_pversion = 0;
        init_waitqueue_entry(&wait, current);
        add_wait_queue(&rmidi->open_wait, &wait);
        while (1) {