Need some help resolving smart contract warnings

Question

New solidity programmer here.

I'm trying to create a smart contract where a user can create a Bounty. The creator sets the bounty on the smart contract in the constructor. They can subsequently choose the recipient of the funds after evaluation of some criteria. They can cancel, increase the bounty.

I tested the code out and it appears to work, but I'm getting some warnings in remix IDE that I don't know how to fix.

Could some one show me how its supposed to be done?

contract Bounty {
    address payable public owner;
    address payable public provider;
    uint256 private bounty;
    bool isActive;
    event IncreaseBounty (uint256 oldBounty, uint256 newBounty);
    event Paid(address owner, address payee, uint256 amount);
    event Cancel(address owner, uint256 amount);

    constructor() payable {
        owner = payable(msg.sender);
        bounty = msg.value;
        isActive = true;
    }

    function cancel() public {
        require(isActive, "contract must be active");
        require(owner == msg.sender, "Only the owner can cancel the bounty");
        uint256 bountyTemp = bounty;
        bounty = 0;
        owner.transfer(bountyTemp);
        isActive = false;
        emit Cancel(msg.sender, bountyTemp);
    }

    function setAndTransferToProvider(address addy) public {
        require(isActive, "contract must be active");
        require(owner == msg.sender, "Only the owner release the funds");
        provider = payable(addy);
        provider.transfer(bounty);
        uint256 bountyUsed = bounty;
        bounty = 0;
        isActive = false;
        emit Paid(owner, provider, bountyUsed);
    }

    function increaseBounty() payable external returns (uint256) {
        require(isActive, "contract must be active");
        require(owner == msg.sender, "Only the owner can increase the bounty");
        uint oldBounty = bounty;
        bounty += uint(msg.value);
        emit IncreaseBounty(oldBounty, bounty);
        return bounty;
    }
    
    function getBounty() public view returns (uint256) {
        require(isActive, "contract must be active");
        return bounty;
    }
}

Answer 1

Try to put this line

provider.transfer(bounty);

right before the emit of the events on every function.

You can check this article for more understanding of reentrancy attacks.