fix integer underflow (ethereum#374)

Signed-off-by: Ignacio Hagopian <jsign.uy@gmail.com>
weiihann · Feb 15, 2024 · 4767773 · 4767773
1 parent 540fa4e
commit 4767773
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
@@ -401,11 +401,13 @@ func touchCodeChunksRangeOnReadAndChargeGas(contractAddr []byte, startPC, size u
  return 0
  }
 
- // endPC is the last PC that must be touched.
- endPC := startPC + size - 1
- if startPC+size > codeLen {
+ endPC := startPC + size
+ if endPC > codeLen {
  endPC = codeLen
  }
+ if endPC > 0 {
+ endPC -= 1 // endPC is the last bytecode that will be touched.
+ }
 
  var statelessGasCharged uint64
  for chunkNumber := startPC / 31; chunkNumber <= endPC/31; chunkNumber++ {