From 874e1f6fad9a5184b67f4cee37c1335cd2cc5677 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 4 Jan 2017 12:19:15 +0100 Subject: ALSA: vx: Fix possible transfer overflow 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 --- sound/pcmcia/vx/vxp_ops.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'sound/pcmcia') diff --git a/sound/pcmcia/vx/vxp_ops.c b/sound/pcmcia/vx/vxp_ops.c index 281972913c32..56aa1ba73ccc 100644 --- a/sound/pcmcia/vx/vxp_ops.c +++ b/sound/pcmcia/vx/vxp_ops.c @@ -369,12 +369,12 @@ static void vxp_dma_write(struct vx_core *chip, struct snd_pcm_runtime *runtime, 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 *chip, struct snd_pcm_runtime *runtime, 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 *chip, struct snd_pcm_runtime *runtime, 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 *chip, struct snd_pcm_runtime *runtime, 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; -- cgit v1.2.3-58-ga151