evm_tokens: fix potential nil-pointer dereference

[ptrus]

On Testnet Production:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1109189]

goroutine 70736 [running]:
github.com/oasisprotocol/oasis-indexer/analyzer/evmtokens.Main.processStaleToken({{0x14cb622, 0x8}, {0x18b5680, 0xc000450a30}, {0x18bbc40, 0xc0003a6370}, 0xc0006ac4e0}, {0x18b39b0, 0xc000922f80}, 0xc000b771e0, ...)
        /code/go/analyzer/evmtokens/evm_tokens.go:122 +0x449
github.com/oasisprotocol/oasis-indexer/analyzer/evmtokens.Main.processBatch.func1()
        /code/go/analyzer/evmtokens/evm_tokens.go:170 +0x4e
golang.org/x/sync/errgroup.(*Group).Go.func1()
        /go/pkg/mod/golang.org/x/[email protected]/errgroup/errgroup.go:75 +0x64
created by golang.org/x/sync/errgroup.(*Group).Go
        /go/pkg/mod/golang.org/x/[email protected]/errgroup/errgroup.go:72 +0xa5

Looking at the code, the EVMDownloadNewToken can return EVMTokenTypeUnsupported which will cause tokenData.TotalSupply to be nil (so shouldn't call .String() on it without checking): https://github.com/oasisprotocol/oasis-indexer/blob/f33b4a9558b4d5736af5c137592ed951cf1c0fff/analyzer/runtime/evm/client.go#L243

---

Don't have a lot of context about the code around here, so I just pushed a minimal change to avoid the nil pointer here.

[pro-wh]

testnet, was this emerald? can we figure out the height and/or contract address? the ERC spec says the total supply is required. we're meant to treat the contract as not ERC-20 if the total supply is not supported

[ptrus]

was this emerald

Looking at the DB it looks like this is sapphire. (there is no stale emerald tokens found if running the RuntimeEVMTokenAnalysisStale query).

Also, a lot of "ERC20 call failed" errors in the logs:

2023-06-05T05:31:41.558081128Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: rpc error: code = Canceled desc = context canceled","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454725,"token_eth_addr_hex":"ed33e0bb03fefd0f343f634c3f40a5f6839753f2","ts":"2023-06-05T05:31:41.557871724Z"}
2023-06-05T05:31:41.559847210Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: rpc error: code = Canceled desc = context canceled","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454725,"token_eth_addr_hex":"d708be8af397cd28b69520db3bd2d92429efb1a8","ts":"2023-06-05T05:31:41.559580189Z"}
2023-06-05T05:31:41.561058059Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: rpc error: code = Canceled desc = context canceled","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454725,"token_eth_addr_hex":"8e6b9362275b93c0e4da3662938456dff485604f","ts":"2023-06-05T05:31:41.560914619Z"}
2023-06-05T05:31:47.634407918Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: roothash: block not found","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454754,"token_eth_addr_hex":"af0d800b67f2688e4c40e1879537df956f3f1c12","ts":"2023-06-05T05:31:47.634183789Z"}
2023-06-05T05:31:47.634454950Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: rpc error: code = Canceled desc = context canceled","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454754,"token_eth_addr_hex":"d239ce2b79f1d9757c6fe6bf44f83bf74a969010","ts":"2023-06-05T05:31:47.634317936Z"}
2023-06-05T05:31:47.634489488Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: rpc error: code = Canceled desc = context canceled","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454754,"token_eth_addr_hex":"06f3c5b365c7af22140c1f5cd3f80a43c186df3a","ts":"2023-06-05T05:31:47.634388413Z"}
...
...
2023-06-05T05:32:11.968103275Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: reverted: no revert reason","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454857,"token_eth_addr_hex":"13f000cb55295d846b8a014ebfb63917a21c7d14","ts":"2023-06-05T05:32:11.96794633Z"}
2023-06-05T05:32:11.974407688Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: reverted: no revert reason","level":"info","method":"name","module":"analysis_service","msg":"ERC20 call failed","round":1454857,"token_eth_addr_hex":"d708be8af397cd28b69520db3bd2d92429efb1a8","ts":"2023-06-05T05:32:11.974252006Z"}
2023-06-05T05:32:11.983481180Z {"analyzer":"evm_tokens_sapphire","caller":"client.go:180","err":"runtime client evm simulate call: reverted: no revert reason","level":"info","method":"name","module":"analysis_serv

[kostko]

Also, a lot of "ERC20 call failed" errors in the logs:

Are there any successful ones as well or do they all fail?

[ptrus]

It could be that all are failing, not sure how to check actually, I don't think there's anything logged for successful calls. Someone that understands the tokens analysis code should probably check.

[kostko]

If all are failing this likely means that the client node is not configured correctly or is not whitelisted for key manager access. @gw0 do you know?

[gw0]

If all are failing this likely means that the client node is not configured correctly or is not whitelisted for key manager access. @gw0 do you know?

Looks correct. The production testnet-oasis-indexer is using our internal Testnet Sapphire gRPC node. Its P2P pubkey is whitelisted in our Testnet Keymanager nodes.

[ptrus]

Yeah some calls are working, since here e.g. simulate call works (but is reverted).

---

@pro-wh This is sapphire, see the round and address in the log message below.

{
    "analyzer": "evm_tokens_sapphire",
    "caller": "client.go:157",
    "err": "runtime client evm simulate call: reverted: no revert reason",
    "level": "info",
    "method": "totalSupply",
    "module": "analysis_service",
    "msg": "ERC20 call failed",
    "round": 1467342,
    "token_eth_addr_hex": "98b50e303836bf301221ddf715a154dde7cbfd56",
    "ts": "2023-06-06T07:18:15.563730585Z"
}

This happens here: https://github.com/oasisprotocol/oasis-indexer/blob/f33b4a9558b4d5736af5c137592ed951cf1c0fff/analyzer/runtime/evm/client.go#L210-L216

Which then causes the EVMDownloadNewToken to return:
https://github.com/oasisprotocol/oasis-indexer/blob/f33b4a9558b4d5736af5c137592ed951cf1c0fff/analyzer/runtime/evm/client.go#L243

Which causes the nil pointer here:
https://github.com/oasisprotocol/oasis-indexer/blob/f33b4a9558b4d5736af5c137592ed951cf1c0fff/analyzer/evmtokens/evm_tokens.go#L122

[pro-wh]

oh right we're inserting the unsupported tokens now