tarball: detect symlink cycles in extractFileFromTar#2232
Merged
Subserial merged 2 commits intogoogle:mainfrom Mar 17, 2026
Merged
tarball: detect symlink cycles in extractFileFromTar#2232Subserial merged 2 commits intogoogle:mainfrom
Subserial merged 2 commits intogoogle:mainfrom
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extractFileFromTar follows symlink and hard link entries recursively without tracking visited paths. A tar containing a link cycle (e.g., manifest.json -> config.json -> manifest.json) causes unbounded recursion until goroutine stack exhaustion crashes the process. Track visited paths during link resolution and return an error when a cycle is detected.
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Mar 17, 2026
Codecov Report✅ All modified and coverable lines are covered by tests.
Additional details and impacted files@@ Coverage Diff @@
## main #2232 +/- ##
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- Coverage 71.67% 52.74% -18.94%
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Files 123 164 +41
Lines 9935 11113 +1178
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- Hits 7121 5861 -1260
- Misses 2115 4546 +2431
- Partials 699 706 +7 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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extractFileFromTar follows symlinks by recursively calling itself with the link target, but doesn't track which paths it has already visited. A two-entry tar where manifest.json and config.json point at each other recurses until the goroutine stack hits ~1GB and the process crashes via runtime.abort().
This is reachable through tarball.Image(), tarball.ImageFromPath(), and the layer access methods -- basically anything that loads a Docker tarball. The fix passes a visited set through the recursive calls and returns an error when it sees a path twice.