diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 6009b1477232..e2af75a205ea 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -551,6 +551,9 @@ static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
 	u32 crc = ~(u32)0;
 	unsigned offset = 0;
 
+	if (index >= io_ctl->num_pages)
+		return -EIO;
+
 	if (index == 0)
 		offset = sizeof(u32) * io_ctl->num_pages;