The process aleth-vm throws an OutofMemoryError when it detect an "infinite loop" #5908
Description
aleth version: 1.8.0
Operating system: Linux
Installation: built from source
when I use the binary aleth-vm to run the following code, the following bytecode contains an "infinite loop", it will not print trace information and terminate the operation correctly until the gas limit is used up.
./aleth-vm_1.8.0 stats --code 608060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063f8a8fd6d146044575b600080fd5b348015604f57600080fd5b506056606c565b6040518082815260200191505060405180910390f35b600080600190505b600581101560745760005481600054020160008190555080806001019150506074565b600054915050905600a165627a7a7230582010c05846ebb8bfc4e2e4c1d67c00000000000000008ae603dce419deaac37d13cb56c3c43a1bc2950029 --mnemonics --input f8a8fd6d
The corresponding control flow graph is as follow, we can observe an infinite loop in block 0x74
The corresponding set of opcode sequences is as follow,
However, when I use the binary aleth-vm to run the following code, the following bytecode also contains an "infinite loop", it will continue to occupy CPU resources until the system kills the whole process. In addition, aleth throws OutOfMemoryError when it crashes.
./aleth-vm_1.8.0 stats --code 608060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063f8a8fd6d146044575b600080fd5b348015604f57600080fd5b506056606c565b6040518082815260200191505060405180910390f35b600080600190505b6005811015604f5760005481600054020160008190555080806001019150506074575b600054915050905600a165627a7a7230582010c05846ebb8bfc4e2e4c1d67c00000000000000008ae603dce419deaac37d13cb56c3c43a1bc2950029 --mnemonics --input f8a8fd6d
The corresponding control flow graph is as follow, we can observe an infinite loop in blocks 0x4f, 0x6c, 0x74.
The corresponding opcode sequences is as follow,
We provide enough gas limit when run two piece of bytecode both contain an infinite loop, but aleth run normally for one and throws OutOfMemoryErrors for another one. This corner cases may expose a bug in aleth's EVM implementation.