Fix File.cp_r/3 infinite loop with symlink cycles#15152
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josevalim merged 1 commit intoelixir-lang:mainfrom Mar 9, 2026
Merged
Fix File.cp_r/3 infinite loop with symlink cycles#15152josevalim merged 1 commit intoelixir-lang:mainfrom
File.cp_r/3 infinite loop with symlink cycles#15152josevalim merged 1 commit intoelixir-lang:mainfrom
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josevalim
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Mar 8, 2026
josevalim
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Mar 8, 2026
| resolved = Path.expand(link, Path.dirname(src)) | ||
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| if MapSet.member?(visited, resolved) do | ||
| {:error, :eloop, src} |
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eloop is a new code, right? It may be better to use one of the existing ones, such as einval.
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this is a standard posix error and I think the semantically correct for this case:
iex> :file.format_error(:eloop)
~c"too many levels of symbolic links"
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When `dereference_symlinks: true` was set and there was a symlink cycle
(e.g., a -> b -> a), the function would infinitely recurse. This fix
tracks visited paths using a `MapSet` and returns `{:error, :eloop, path}`
when a cycle is detected.
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When
dereference_symlinks: truewas set and there was a symlink cycle (e.g., a -> b -> a), the function would infinitely recurse. This fix tracks visited paths using aMapSetand returns{:error, :eloop, path}when a cycle is detected.Reproduce with: