diff mbox

audio: intel-hda: check stream entry count during transfer

Message ID 1476949224-6865-1-git-send-email-ppandit@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Prasad Pandit Oct. 20, 2016, 7:40 a.m. UTC 
From: Prasad J Pandit <pjp@fedoraproject.org>

Intel HDA emulator uses stream of buffers during DMA data
transfers. Each entry has buffer length and buffer pointer
position, which are used to derive bytes to 'copy'. If this
length and buffer pointer were to be same, 'copy' could be
set to zero(0), leading to an infinite loop. Add check to
avoid it.

Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/audio/intel-hda.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Stefan Hajnoczi Oct. 20, 2016, 9:37 a.m. UTC | #1 
On Thu, Oct 20, 2016 at 01:10:24PM +0530, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
> 
> Intel HDA emulator uses stream of buffers during DMA data
> transfers. Each entry has buffer length and buffer pointer
> position, which are used to derive bytes to 'copy'. If this
> length and buffer pointer were to be same, 'copy' could be
> set to zero(0), leading to an infinite loop. Add check to
> avoid it.
> 
> Reported-by: Huawei PSIRT <psirt@huawei.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>  hw/audio/intel-hda.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Gerd Hoffmann Oct. 26, 2016, 12:48 p.m. UTC | #2 
On Do, 2016-10-20 at 13:10 +0530, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
> 
> Intel HDA emulator uses stream of buffers during DMA data
> transfers. Each entry has buffer length and buffer pointer
> position, which are used to derive bytes to 'copy'. If this
> length and buffer pointer were to be same, 'copy' could be
> set to zero(0), leading to an infinite loop. Add check to
> avoid it.
> 
> Reported-by: Huawei PSIRT <psirt@huawei.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>

Added to audio patch queue.

thanks,
  Gerd
diff mbox

Patch

diff --git a/hw/audio/intel-hda.c b/hw/audio/intel-hda.c
index cd95340..537face 100644
--- a/hw/audio/intel-hda.c
+++ b/hw/audio/intel-hda.c
@@ -416,7 +416,8 @@  static bool intel_hda_xfer(HDACodecDevice *dev, uint32_t stnr, bool output,
     }
 
     left = len;
-    while (left > 0) {
+    s = st->bentries;
+    while (left > 0 && s-- > 0) {
         copy = left;
         if (copy > st->bsize - st->lpib)
             copy = st->bsize - st->lpib;