diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ffbbf0520d9e8f8f566cb790642fd78647767410..4f818f7fa155e6407d788bf7f18b45d300a96231 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -158,8 +158,14 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 	err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
 	if (err)
 		return err;
+	if (!phys) {
+		fat_fs_error(sb,
+			     "invalid FAT chain (i_pos %lld, last_block %llu)",
+			     MSDOS_I(inode)->i_pos,
+			     (unsigned long long)last_block);
+		return -EIO;
+	}
 
-	BUG_ON(!phys);
 	BUG_ON(*max_blocks != mapped_blocks);
 	set_buffer_new(bh_result);
 	map_bh(bh_result, sb, phys);