Patch "ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
alsa-seq-fix-snd_seq_call_port_info_ioctl-in-compat-mode.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nicolas Boichat <[email protected]>
Date: Mon, 18 Jan 2016 21:35:01 +0800
Subject: ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode

From: Nicolas Boichat <[email protected]>

commit 9586495dc3011a80602329094e746dbce16cb1f1 upstream.

This reverts one hunk of
commit ef44a1ec6eee ("ALSA: sound/core: use memdup_user()"), which replaced a number of kmalloc followed by memcpy with memdup calls.

In this case, we are copying from a struct snd_seq_port_info32 to a struct snd_seq_port_info, but the latter is 4 bytes longer than the 32-bit version, so we need to separate kmalloc and copy calls.

---
 sound/core/seq/seq_compat.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

@@ -49,11 +49,12 @@ static int snd_seq_call_port_info_ioctl(
 	struct snd_seq_port_info *data;
 	mm_segment_t fs;
 
-	data = memdup_user(data32, sizeof(*data32));
-	if (IS_ERR(data))
-		return PTR_ERR(data);
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
 
-	if (get_user(data->flags, &data32->flags) ||
+	if (copy_from_user(data, data32, sizeof(*data32)) ||
+	    get_user(data->flags, &data32->flags) ||
 	    get_user(data->time_queue, &data32->time_queue))
 		goto error;
 	data->kernel = NULL;

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/alsa-pcm-fix-snd_pcm_hw_params-struct-copy-in-compat-mode.patch queue-4.1/alsa-seq-fix-snd_seq_call_port_info_ioctl-in-compat-mode.patch