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| author | Takashi Iwai <tiwai@suse.de> | 2017-01-04 12:19:15 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-01-04 18:01:35 +0100 |
| commit | 874e1f6fad9a5184b67f4cee37c1335cd2cc5677 (patch) | |
| tree | 352304fa4287e1d7d9b5522f46f26fc8c92dcf9d /sound/pcmcia | |
| parent | ab949d519601880fd46e8bc1445d6a453bf2dc09 (diff) | |
| download | linux-874e1f6fad9a5184b67f4cee37c1335cd2cc5677.tar.gz linux-874e1f6fad9a5184b67f4cee37c1335cd2cc5677.tar.bz2 linux-874e1f6fad9a5184b67f4cee37c1335cd2cc5677.zip | |
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 <tiwai@suse.de>
Diffstat (limited to 'sound/pcmcia')
| -rw-r--r-- | sound/pcmcia/vx/vxp_ops.c | 12 |
1 files changed, 6 insertions, 6 deletions
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; |