New subject: [alsa-devel] [patch] ALSA: isa/wavefront: prevent some out of bound writes

4 May 2016

"header->number" can be up to USHRT_MAX and it comes from the ioctl so
it needs to be capped.
Signed-off-by: Dan Carpenter dan.carpenter@oracle.com

diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c
index 69f76ff..718d5e3 100644
--- a/sound/isa/wavefront/wavefront_synth.c
+++ b/sound/isa/wavefront/wavefront_synth.c
@@ -785,6 +785,9 @@ wavefront_send_patch (snd_wavefront_t *dev, wavefront_patch_info *header)
    DPRINT (WF_DEBUG_LOAD_PATCH, "downloading patch %d\n",
    			      header->number);
+	if (header->number >= ARRAY_SIZE(dev->patch_status))
+		return -EINVAL;
+
    dev->patch_status[header->number] |= WF_SLOT_FILLED;
bptr = buf;
@@ -809,6 +812,9 @@ wavefront_send_program (snd_wavefront_t *dev, wavefront_patch_info *header)
    DPRINT (WF_DEBUG_LOAD_PATCH, "downloading program %d\n",
    	header->number);
+	if (header->number >= ARRAY_SIZE(dev->prog_status))
+		return -EINVAL;
+
    dev->prog_status[header->number] = WF_SLOT_USED;
/* XXX need to zero existing SLOT_USED bit for program_status[i]
@@ -898,6 +904,9 @@ wavefront_send_sample (snd_wavefront_t *dev,
    	header->number = x;
    }
+	if (header->number >= WF_MAX_SAMPLE)
+		return -EINVAL;
+
    if (header->size) {
/* XXX it's a debatable point whether or not RDONLY semantics

    

Dan Carpenter