Terrascan casually panicing when downloading GCP provider

[torbendury]

• terrascan version: latest
• Operating System: Linux/Debian

Description

I try scanning my Terraform code with the GCP provider. I enable verbose output, set the log level to error and configure terrascan to scan non-recursive.

Sometimes, I get this error when terrascan tries to download the provider:

2023/09/13 13:39:54 [DEBUG] GET https://registry.terraform.io/v1/providers/hashicorp/google/versions
panic: runtime error: slice bounds out of range [:1311] with capacity 1308

goroutine 7 [running]:
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.(*converter).rangeSource(...)
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/convert.go:43
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.(*converter).wrapExpr(...)
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/convert.go:294
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.(*converter).convertExpression(0xc000c234b8, {0x373a6e0, 0xc0004a13b0})
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/convert.go:195 +0x49c
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.(*converter).convertExpression(0xc000c234b8, {0x373a7a0, 0xc0007e7e00})
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/convert.go:188 +0x545
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.(*converter).convertBody(0xc00005ac60?, 0xc0008ce210)
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/convert.go:56 +0xe7
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.CreateResourceConfig(_)
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/resource.go:48 +0x125
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.TerraformDirectoryLoader.loadDirNonRecursive({{0xc000160ac0, 0x34}, 0x1, 0x0, {0x37383a8, 0xc000ca0de0}, 0xc0001290e0, 0x0, 0xc000ca0e40, {0x305c94c, ...}})
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/load-dir.go:333 +0xad8
github.com/tenable/terrascan/pkg/iac-providers/terraform/commons.TerraformDirectoryLoader.LoadIacDir({{0xc000160ac0, 0x34}, 0x1, 0x0, {0x37383a8, 0xc000ca0de0}, 0xc0001290e0, 0x0, 0xc000ca0e40, {0x305c94c, ...}})
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/commons/load-dir.go:115 +0xdb
github.com/tenable/terrascan/pkg/iac-providers/terraform/v15.(*TfV15).LoadIacDir(0x0, {0xc000160ac0?, 0x0?}, 0x0?)
	/home/runner/work/terrascan/terrascan/pkg/iac-providers/terraform/v15/load-dir.go:30 +0x98
github.com/tenable/terrascan/pkg/runtime.(*Executor).getResourceConfigs.func1({0x7f822dca82c0, 0x4f015c8})
	/home/runner/work/terrascan/terrascan/pkg/runtime/executor.go:318 +0x4b
created by github.com/tenable/terrascan/pkg/runtime.(*Executor).getResourceConfigs
	/home/runner/work/terrascan/terrascan/pkg/runtime/executor.go:317 +0x76f

However this is only reproducable when I set the -l error flag. When I do not set it, this does not happen.

What I Did

terrascan init
terrascan scan -i terraform -t gcp -v --non-recursive -l error