@@ -54,12 +54,17 @@ static long long squashfs_inode_lookup(s
struct squashfs_sb_info *msblk = sb->s_fs_info;
int blk = SQUASHFS_LOOKUP_BLOCK(ino_num - 1);
int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino_num - 1);
- u64 start = le64_to_cpu(msblk->inode_lookup_table[blk]);
+ u64 start;
__le64 ino;
int err;
TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino_num);
+ if (ino_num == 0 || (ino_num - 1) >= msblk->inodes)
+ return -EINVAL;
+
+ start = le64_to_cpu(msblk->inode_lookup_table[blk]);
+
err = squashfs_read_metadata(sb, &ino, &start, &offset, sizeof(ino));
if (err < 0)
return err;
@@ -124,7 +129,10 @@ __le64 *squashfs_read_inode_lookup_table
u64 lookup_table_start, u64 next_table, unsigned int inodes)
{
unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(inodes);
+ unsigned int indexes = SQUASHFS_LOOKUP_BLOCKS(inodes);
+ int n;
__le64 *table;
+ u64 start, end;
TRACE("In read_inode_lookup_table, length %d\n", length);
@@ -134,20 +142,37 @@ __le64 *squashfs_read_inode_lookup_table
if (inodes == 0)
return ERR_PTR(-EINVAL);
- /* length bytes should not extend into the next table - this check
- * also traps instances where lookup_table_start is incorrectly larger
- * than the next table start
+ /*
+ * The computed size of the lookup table (length bytes) should exactly
+ * match the table start and end points
*/
- if (lookup_table_start + length > next_table)
+ if (length != (next_table - lookup_table_start))
return ERR_PTR(-EINVAL);
table = squashfs_read_table(sb, lookup_table_start, length);
+ if (IS_ERR(table))
+ return table;
/*
- * table[0] points to the first inode lookup table metadata block,
- * this should be less than lookup_table_start
+ * table0], table[1], ... table[indexes - 1] store the locations
+ * of the compressed inode lookup blocks. Each entry should be
+ * less than the next (i.e. table[0] < table[1]), and the difference
+ * between them should be SQUASHFS_METADATA_SIZE or less.
+ * table[indexes - 1] should be less than lookup_table_start, and
+ * again the difference should be SQUASHFS_METADATA_SIZE or less
*/
- if (!IS_ERR(table) && le64_to_cpu(table[0]) >= lookup_table_start) {
+ for (n = 0; n < (indexes - 1); n++) {
+ start = le64_to_cpu(table[n]);
+ end = le64_to_cpu(table[n + 1]);
+
+ if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ start = le64_to_cpu(table[indexes - 1]);
+ if (start >= lookup_table_start || (lookup_table_start - start) > SQUASHFS_METADATA_SIZE) {
kfree(table);
return ERR_PTR(-EINVAL);
}