[018/119] sound: rawmidi: fix checking of O_APPEND when opening MIDI device

[Greg KH]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Clemens Ladisch <clemens@xxxxxxxxxx>

commit 16fb109644b5644e42ececeff644514de6f4bd03 upstream.

Commit 9a1b64caac82aa02cb74587ffc798e6f42c6170a in 2.6.30 dropped the
check that a substream must already have been opened with O_APPEND to be
able to open it a second time.

This would make it possible for a substream to be switched to append
mode, which would mean that non-atomic writes would fail unexpectedly.

Signed-off-by: Clemens Ladisch <clemens@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 sound/core/rawmidi.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -248,7 +248,8 @@ static int assign_substream(struct snd_r
 	list_for_each_entry(substream, &s->substreams, list) {
 		if (substream->opened) {
 			if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
-			    !(mode & SNDRV_RAWMIDI_LFLG_APPEND))
+			    !(mode & SNDRV_RAWMIDI_LFLG_APPEND) ||
+			    !substream->append)
 				continue;
 		}
 		if (subdevice < 0 || subdevice == substream->number) {


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/