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Patch "ALSA: vx: Fix possible transfer overflow" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Nov 19, 2017

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

ALSA: vx: Fix possible transfer overflow

to the 4.9-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-vx-fix-possible-transfer-overflow.patch
and it can be found in the queue-4.9 subdirectory.

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

Quoted 1 line

From foo@baz Sun Nov 19 11:32:28 CET 2017

From: Takashi Iwai <[email protected]>
Date: Wed, 4 Jan 2017 12:19:15 +0100
Subject: ALSA: vx: Fix possible transfer overflow

From: Takashi Iwai <[email protected]>

[ Upstream commit 874e1f6fad9a5184b67f4cee37c1335cd2cc5677 ]

The pseudo DMA transfer codes in VX222 and VX-pocket driver have a slight bug where they check the buffer boundary wrongly, and may overflow. Also, the zero sample count might be handled badly for the playback (although it shouldn't happen in theory). This patch addresses these issues.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=141541

Signed-off-by Takashi Iwai <[email protected]>
Signed-off-by Sasha Levin <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 sound/drivers/vx/vx_pcm.c   |    6 ++++--
 sound/pci/vx222/vx222_ops.c |   12 ++++++------
 sound/pcmcia/vx/vxp_ops.c   |   12 ++++++------
 3 files changed, 16 insertions(+), 14 deletions(-)
sound/drivers/vx/vx_pcm.c +4 -2
@@ -1048,8 +1048,10 @@ static void vx_pcm_capture_update(struct
 		/* ok, let's accelerate! */
 		int align = pipe->align * 3;
 		space = (count / align) * align;
-		vx_pseudo_dma_read(chip, runtime, pipe, space);
-		count -= space;
+		if (space > 0) {
+			vx_pseudo_dma_read(chip, runtime, pipe, space);
+			count -= space;
+		}
 	}
 	/* read the rest of bytes */
 	while (count > 0) {
sound/pci/vx222/vx222_ops.c +6 -6
@@ -269,12 +269,12 @@ static void vx2_dma_write(struct vx_core
 
 	/* Transfer using pseudo-dma.
 	 */
-	if (offset + count > pipe->buffer_bytes) {
+	if (offset + count >= pipe->buffer_bytes) {
 		int length = pipe->buffer_bytes - offset;
 		count -= length;
 		length >>= 2; /* in 32bit words */
 		/* Transfer using pseudo-dma. */
-		while (length-- > 0) {
+		for (; length > 0; length--) {
 			outl(cpu_to_le32(*addr), port);
 			addr++;
 		}

@@ -284,7 +284,7 @@ static void vx2_dma_write(struct vx_core
 	pipe->hw_ptr += count;
 	count >>= 2; /* in 32bit words */
 	/* Transfer using pseudo-dma. */
-	while (count-- > 0) {
+	for (; count > 0; count--) {
 		outl(cpu_to_le32(*addr), port);
 		addr++;
 	}

@@ -307,12 +307,12 @@ static void vx2_dma_read(struct vx_core
 	vx2_setup_pseudo_dma(chip, 0);
 	/* Transfer using pseudo-dma.
 	 */
-	if (offset + count > pipe->buffer_bytes) {
+	if (offset + count >= pipe->buffer_bytes) {
 		int length = pipe->buffer_bytes - offset;
 		count -= length;
 		length >>= 2; /* in 32bit words */
 		/* Transfer using pseudo-dma. */
-		while (length-- > 0)
+		for (; length > 0; length--)
 			*addr++ = le32_to_cpu(inl(port));
 		addr = (u32 *)runtime->dma_area;
 		pipe->hw_ptr = 0;

@@ -320,7 +320,7 @@ static void vx2_dma_read(struct vx_core
 	pipe->hw_ptr += count;
 	count >>= 2; /* in 32bit words */
 	/* Transfer using pseudo-dma. */
-	while (count-- > 0)
+	for (; count > 0; count--)
 		*addr++ = le32_to_cpu(inl(port));
 
 	vx2_release_pseudo_dma(chip);
sound/pcmcia/vx/vxp_ops.c +6 -6
@@ -369,12 +369,12 @@ static void vxp_dma_write(struct vx_core
 	unsigned short *addr = (unsigned short *)(runtime->dma_area + offset);
 
 	vx_setup_pseudo_dma(chip, 1);
-	if (offset + count > pipe->buffer_bytes) {
+	if (offset + count >= pipe->buffer_bytes) {
 		int length = pipe->buffer_bytes - offset;
 		count -= length;
 		length >>= 1; /* in 16bit words */
 		/* Transfer using pseudo-dma. */
-		while (length-- > 0) {
+		for (; length > 0; length--) {
 			outw(cpu_to_le16(*addr), port);
 			addr++;
 		}

@@ -384,7 +384,7 @@ static void vxp_dma_write(struct vx_core
 	pipe->hw_ptr += count;
 	count >>= 1; /* in 16bit words */
 	/* Transfer using pseudo-dma. */
-	while (count-- > 0) {
+	for (; count > 0; count--) {
 		outw(cpu_to_le16(*addr), port);
 		addr++;
 	}

@@ -411,12 +411,12 @@ static void vxp_dma_read(struct vx_core
 	if (snd_BUG_ON(count % 2))
 		return;
 	vx_setup_pseudo_dma(chip, 0);
-	if (offset + count > pipe->buffer_bytes) {
+	if (offset + count >= pipe->buffer_bytes) {
 		int length = pipe->buffer_bytes - offset;
 		count -= length;
 		length >>= 1; /* in 16bit words */
 		/* Transfer using pseudo-dma. */
-		while (length-- > 0)
+		for (; length > 0; length--)
 			*addr++ = le16_to_cpu(inw(port));
 		addr = (unsigned short *)runtime->dma_area;
 		pipe->hw_ptr = 0;

@@ -424,7 +424,7 @@ static void vxp_dma_read(struct vx_core
 	pipe->hw_ptr += count;
 	count >>= 1; /* in 16bit words */
 	/* Transfer using pseudo-dma. */
-	while (count-- > 1)
+	for (; count > 1; count--)
 		*addr++ = le16_to_cpu(inw(port));
 	/* Disable DMA */
 	pchip->regDIALOG &= ~VXP_DLG_DMAREAD_SEL_MASK;

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

queue-4.9/alsa-vx-don-t-try-to-update-capture-stream-before-running.patch queue-4.9/alsa-vx-fix-possible-transfer-overflow.patch queue-4.9/alsa-hda-realtek-add-new-codec-id-alc299.patch