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7114360901
This fixes an inifinite loop in mkdirAs(), used by `MkdirAllAndChown`,
`MkdirAndChown`, and `MkdirAllAndChownNew`, as well as directories being
chown'd multiple times when relative paths are used.
The for loop in this function was incorrectly assuming that;
1. `filepath.Dir()` would always return the parent directory of any given path
2. traversing any given path to ultimately result in "/"
While this is correct for absolute and "cleaned" paths, both assumptions are
incorrect in some variations of "path";
1. for paths with a trailing path-separator ("some/path/"), or dot ("."),
`filepath.Dir()` considers the (implicit) "." to be a location _within_ the
directory, and returns "some/path" as ("parent") directory. This resulted
in the path itself to be included _twice_ in the list of paths to chown.
2. for relative paths ("./some-path", "../some-path"), "traversing" the path
would never end in "/", causing the for loop to run indefinitely:
```go
// walk back to "/" looking for directories which do not exist
// and add them to the paths array for chown after creation
dirPath := path
for {
dirPath = filepath.Dir(dirPath)
if dirPath == "/" {
break
}
if _, err := os.Stat(dirPath); err != nil && os.IsNotExist(err) {
paths = append(paths, dirPath)
}
}
```
A _partial_ mitigation for this would be to use `filepath.Clean()` before using
the path (while `filepath.Dir()` _does_ call `filepath.Clean()`, it only does so
_after_ some processing, so only cleans the result). Doing so would prevent the
double chown from happening, but would not prevent the "final" path to be "."
or ".." (in the relative path case), still causing an infinite loop, or
additional checks for "." / ".." to be needed.
| path | filepath.Dir(path) | filepath.Dir(filepath.Clean(path)) |
|----------------|--------------------|------------------------------------|
| some-path | . | . |
| ./some-path | . | . |
| ../some-path | .. | .. |
| some/path/ | some/path | some |
| ./some/path/ | some/path | some |
| ../some/path/ | ../some/path | ../some |
| some/path/. | some/path | some |
| ./some/path/. | some/path | some |
| ../some/path/. | ../some/path | ../some |
| /some/path/ | /some/path | /some |
| /some/path/. | /some/path | /some |
Instead, this patch adds a `filepath.Abs()` to the function, so make sure that
paths are both cleaned, and not resulting in an infinite loop.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit
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|---|---|---|
| .. | ||
| aaparser | ||
| archive | ||
| authorization | ||
| broadcaster | ||
| capabilities | ||
| chrootarchive | ||
| containerfs | ||
| devicemapper | ||
| directory | ||
| dmesg | ||
| fileutils | ||
| fsutils | ||
| homedir | ||
| idtools | ||
| ioutils | ||
| jsonmessage | ||
| longpath | ||
| loopback | ||
| namesgenerator | ||
| parsers | ||
| pidfile | ||
| platform | ||
| plugingetter | ||
| plugins | ||
| pools | ||
| progress | ||
| pubsub | ||
| reexec | ||
| signal | ||
| stack | ||
| stdcopy | ||
| streamformatter | ||
| stringid | ||
| sysinfo | ||
| system | ||
| tailfile | ||
| tarsum | ||
| truncindex | ||
| urlutil | ||
| useragent | ||
| README.md | ||
pkg/ is a collection of utility packages used by the Moby project without being specific to its internals.
Utility packages are kept separate from the moby core codebase to keep it as small and concise as possible. If some utilities grow larger and their APIs stabilize, they may be moved to their own repository under the Moby organization, to facilitate re-use by other projects. However that is not the priority.
The directory pkg is named after the same directory in the camlistore project. Since Brad is a core
Go maintainer, we thought it made sense to copy his methods for organizing Go code :) Thanks Brad!
Because utility packages are small and neatly separated from the rest of the codebase, they are a good place to start for aspiring maintainers and contributors. Get in touch if you want to help maintain them!