security: harden RevParse and pass --end-of-options across git commands#142
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A revision that starts with a dash is interpreted by "git rev-parse" as a command-line option rather than an object, allowing an authenticated user to inject options such as "--absolute-git-dir" through parameters meant for commit SHAs or branch references and leak internal server details to the error logs. The "--end-of-options" separator does not help here because "git rev-parse" does not honor it for revisions, so reject such input outright. RevParse is the single funnel for user-controlled revisions (CatFileCommit, blobs, trees, submodules), so the guard closes the whole class at one place.
Bring the master branch up to parity with v2 by adding the "--end-of-options" separator to the remaining commands that accept it: checkout, reset, fetch, pull, commit, count-objects, fsck, for-each-ref, ls-tree, remote, tag, archive, show (blob), receive-pack, upload-pack, and update-server-info. This hardens them against argument injection as a defense-in-depth measure.
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Two changes:
RevParse guard (the fix). A revision that starts with a dash is interpreted by
git rev-parseas a command-line option rather than an object, allowing an authenticated caller to inject git options through parameters meant for commit SHAs or branch references.--end-of-optionsdoes not help here becausegit rev-parsedoes not honor it for revisions, so this rejects such input outright.RevParseis the single funnel for user-controlled revisions (CatFileCommit, blobs, trees, submodules), so the guard closes the whole class at one place.Parity hardening (defense-in-depth). Bring master up to parity with the
v2branch by adding the--end-of-optionsseparator to the remaining commands that accept it: checkout, reset, fetch, pull, commit, count-objects, fsck, for-each-ref, ls-tree, remote, tag, archive, show (blob), receive-pack, upload-pack, and update-server-info.The v2 counterpart of the guard is #143.
Refs GHSA-mxrh-2rxr-6mqc.