CVE-2018-5146: Prevent out-of-bounds write in codebook decoding.
Codebooks that are not an exact divisor of the partition size are now
truncated to fit within the partition.
@@ -386,7 +386,7 @@ long vorbis_book_decodevs_add(codebook *book,float *a,oggpack_buffer *b,int n){
t[i] = book->valuelist+entry[i]*book->dim;
}
for(i=0,o=0;i<book->dim;i++,o+=step)
- for (j=0;j<step;j++)
+ for (j=0;o+j<n && j<step;j++)
a[o+j]+=t[j][i];
}
return(0);
@@ -398,42 +398,13 @@ long vorbis_book_decodev_add(codebook *book,float *a,oggpack_buffer *b,int n){
int i,j,entry;
float *t;
- if(book->dim>8){
for(i=0;i<n;){
entry = decode_packed_entry_number(book,b);
if(entry==-1)return(-1);
t = book->valuelist+entry*book->dim;
- for (j=0;j<book->dim;)
+ for(j=0;i<n && j<book->dim;)
a[i++]+=t[j++];
}
- }else{
- for(i=0;i<n;){
- entry = decode_packed_entry_number(book,b);
- if(entry==-1)return(-1);
- t = book->valuelist+entry*book->dim;
- j=0;
- switch((int)book->dim){
- case 8:
- a[i++]+=t[j++];
- case 7:
- a[i++]+=t[j++];
- case 6:
- a[i++]+=t[j++];
- case 5:
- a[i++]+=t[j++];
- case 4:
- a[i++]+=t[j++];
- case 3:
- a[i++]+=t[j++];
- case 2:
- a[i++]+=t[j++];
- case 1:
- a[i++]+=t[j++];
- case 0:
- break;
- }
- }
- }
}
return(0);
}
@@ -470,12 +441,13 @@ long vorbis_book_decodevv_add(codebook *book,float **a,long offset,int ch,
long i,j,entry;
int chptr=0;
if(book->used_entries>0){
- for(i=offset/ch;i<(offset+n)/ch;){
+ int m=(offset+n)/ch;
+ for(i=offset/ch;i<m;){
entry = decode_packed_entry_number(book,b);
if(entry==-1)return(-1);
{
const float *t = book->valuelist+entry*book->dim;
- for (j=0;j<book->dim;j++){
+ for (j=0;i<m && j<book->dim;j++){
a[chptr++][i]+=t[j];
if(chptr==ch){
chptr=0;
