bug: anvil_setStorageAt

[adraffy]

Component

Anvil

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.3.0 (5a8bd89 2024-12-20T08:45:54.170904000Z)

What version of Foundryup are you on?

foundryup: 0.3.1

What command(s) is the bug in?

No response

Operating System

macOS (Intel)

Describe the bug

1. Fork mainnet: anvil --fork-url https://rpc.ankr.com/eth

2. Compute storage slot for ENS records[node].resolver

   • node = 0x53a2e7cce84726721578c676b4798972d354dd7c62c832415371716693edd312
     • namehash('default.reverse')
   • SLOT(records) = 0
   • SLOT(records[node]) = 0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb73
     • cast index bytes32 0x53a2e7cce84726721578c676b4798972d354dd7c62c832415371716693edd312 0
   • SLOT(records[node].resolver) =0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb74
     • slot + 1

3. Replace resolver with 0x1

   • cast rpc anvil_setStorageAt 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e 0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb74 0x0000000000000000000000000000000000000000000000000000000000000001

4. Query ENS.resolver(node)

   • cast call 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e "resolver(bytes32)" 0x53a2e7cce84726721578c676b4798972d354dd7c62c832415371716693edd312

5. Answer is 0x0 but Expected 0x1

---

Not sure why this fails? Some kind of off-by-one bug?

For example, here is the same code for raffy.eth

1. (same as 3 but different node) cast rpc anvil_setStorageAt 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e 0x0bfdc7d18a681d5f09834ebfaa1611fe18af3c4a6f4f1a276c3a0734c4885e62 0x0000000000000000000000000000000000000000000000000000000000000001
2. (same as 4 but different node) cast call 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e "resolver(bytes32)" 0x9c8b7ac505c9f0161bbbd04437fce8c630a0886e1ffea00078e298f063a8a5df
3. Answer is 0x1

If I set the slot before it (0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb73) which corresponds to the owner field, then the code above works.

1. set previous slot: cast rpc anvil_setStorageAt 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e 0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb73 0x0000000000000000000000000000000000000000000000000000000000000001
2. (same as 3 above) cast rpc anvil_setStorageAt 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e 0x9f19e10bccde41c24f53ff4dbf7bb5ee2063896e54351d7230ecd1f7e361cb74 0x0000000000000000000000000000000000000000000000000000000000000001
3. (same as 4 above) cast call 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e "resolver(bytes32)" 0x53a2e7cce84726721578c676b4798972d354dd7c62c832415371716693edd312
4. Answer is 0x1

[adraffy]

For reference: ENS

contract ENSRegistry {
    struct Record {
        address owner;
        address resolver; // offset = 1
        uint64 ttl;
    }
    mapping (bytes32 => Record) records; // slot = 0   
    function resolver(bytes32 node) public view returns (address) {
         return records[node].resolver;
    }
}

[yash-atreya]

Able to reproduce. Investigating.