btrfs: lzo: Harden inline lzo compressed extent decompression

For inlined extent, we only have one segment, thus less things to check. And further more, inlined extent always has the csum in its leaf header, it's less probable to have corrupted data. Anyway, still check header and segment header. Signed-off-by: Qu Wenruo <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
fracktal · May 30, 2018 · de885e3 · de885e3
1 parent 314bfa4
commit de885e3
Showing 1 changed file with 10 additions and 1 deletion.
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
@@ -430,15 +430,24 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	size_t in_len;
 	size_t out_len;
+	size_t max_segment_len = lzo1x_worst_compress(PAGE_SIZE);
 	int ret = 0;
 	char *kaddr;
 	unsigned long bytes;
 
-	BUG_ON(srclen < LZO_LEN);
+	if (srclen < LZO_LEN || srclen > max_segment_len + LZO_LEN * 2)
+		return -EUCLEAN;
 
+	in_len = read_compress_length(data_in);
+	if (in_len != srclen)
+		return -EUCLEAN;
 	data_in += LZO_LEN;
 
 	in_len = read_compress_length(data_in);
+	if (in_len != srclen - LZO_LEN * 2) {
+		ret = -EUCLEAN;
+		goto out;
+	}
 	data_in += LZO_LEN;
 
 	out_len = PAGE_SIZE;