Add sanity checks to fix crash
Copy Huffman tree sanity check from libvorbis to avoid out of bounds memory
access later on.
Bug: 21048776
Change-Id: I3c508572501af188af4224e2a295e9f2554ec9c0
(cherry picked from commit 52193fa3472b79873e73044ce02e1c0a67c85043)
diff --git a/Tremolo/codebook.c b/Tremolo/codebook.c
index 0ff3529..66979dc 100644
--- a/Tremolo/codebook.c
+++ b/Tremolo/codebook.c
@@ -210,6 +210,20 @@
}
}
+ // following sanity check copied from libvorbis
+ /* sanity check the huffman tree; an underpopulated tree must be
+ rejected. The only exception is the one-node pseudo-nil tree,
+ which appears to be underpopulated because the tree doesn't
+ really exist; there's only one possible 'codeword' or zero bits,
+ but the above tree-gen code doesn't mark that. */
+ if(b->used_entries != 1){
+ for(i=1;i<33;i++)
+ if(marker[i] & (0xffffffffUL>>(32-i))){
+ return 1;
+ }
+ }
+
+
return 0;
}
