Backport of VAULT-32330: fix sanitize path function to account for backslashes into release/1.18.x

[hc-github-team-secure-vault-core]

Backport

This PR is auto-generated from #28878 to be assessed for backporting due to the inclusion of the label backport/1.18.x.

The below text is copied from the body of the original PR.

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Description

What does this PR do?
Fixes a backslash check in logical_system.go by expanding the check to also include filtering for double forward and back slashes.

TODO only if you're a HashiCorp employee

• Backport Labels: If this PR is in the ENT repo and needs to be backported, backport
  to N, N-1, and N-2, using the backport/ent/x.x.x+ent labels. If this PR is in the CE repo, you should only backport to N, using the backport/x.x.x label, not the enterprise labels.
  • If this fixes a critical security vulnerability or severity 1 bug, it will also need to be backported to the current LTS versions of Vault. To ensure this, use all available enterprise labels.
• ENT Breakage: If this PR either 1) removes a public function OR 2) changes the signature
  of a public function, even if that change is in a CE file, double check that
  applying the patch for this PR to the ENT repo and running tests doesn't
  break any tests. Sometimes ENT only tests rely on public functions in CE
  files.
• Jira: If this change has an associated Jira, it's referenced either
  in the PR description, commit message, or branch name.
• RFC: If this change has an associated RFC, please link it in the description.
• ENT PR: If this change has an associated ENT PR, please link it in the
  description. Also, make sure the changelog is in this PR, not in your ENT PR.

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Overview of commits

• bf13271

[github-actions]

CI Results:
All Go tests succeeded! ✅

[github-actions]

Build Results:
All builds succeeded! ✅

[VioletHynes]

@aslamovamir If the backport PR could be auto-generated, then you don't need to assign us as reviewers, you can review it yourself (just a sanity check)! You only need to add others if it was a manual backport.

[aslamovamir]

Hi @VioletHynes and @divyaac !
Wanted to double check some points with backporting, looks like this backport for version 1.18, but no automated PR was generated for 1.17 though the original PR had the tag for that version 🤔 There was another automated PR generated for version 1.16 on enterprise repo: https://github.com/hashicorp/vault-enterprise/pull/6980. So in total only these 2 PR's were generated, though I expected 6 in total, 3 on vault repo and 3 on enterprise vault repo corresponding to the 3 versions. Is this correct? Also realized the only available labels for version 1.16 and 1.17 is for enterprise

[aslamovamir]

@aslamovamir If the backport PR could be auto-generated, then you don't need to assign us as reviewers, you can review it yourself (just a sanity check)! You only need to add others if it was a manual backport.

Yup, sorry! I added as a reviewer to clarify some points, I added them. But got the note - thanks for clarifying!

[VioletHynes]

For 1.16, you will need to perform the backport manually (make a branch locally and cherry-pick the commit). But in general, I'd expect 3 PRs to be generated by the three labels.

[aslamovamir]

For 1.16, you will need to perform the backport manually (make a branch locally and cherry-pick the commit). But in general, I'd expect 3 PRs to be generated by the three labels.

For 1.16, are you referring to this automated PR on the enterprise vault repo? So no need to backport to 1.16 on OSS vault repo, just the enterprise vault repo?

Removed the tag for version 1.17.x ent and added it again and the automated PR got generated: https://github.com/hashicorp/vault-enterprise/pull/6982#event-15286856315