The check that an entry returned by an archiver is a direct child of
the directory being listed normalised a parent of "/" to the root, so
an entry named "/x" passed as a child of the root while "x/" and
"dir//x" were rejected.
Decide by stripping the directory prefix and checking what is left
with sanitize.Leaf, which rejects an empty name, ".", ".." and any
name containing a "/". This also covers the leading slash case.
A file entry in a zip whose name refers to a directory, such as ".",
"/", "" or "sub/.", was only skipped when it named the root of an
archive which was itself the root of the remote. When the archive was
found by listing its parent directory the entry appeared as a file
with the same name as the archive alongside the directory for it, and
copying the archive tried to write both. When the entry named a
subdirectory it appeared as a file alongside that directory, and with
that subdirectory mounted as the archive root the entry was taken to
be the single file the root points at, hiding every real entry.
Skip any file entry whose last path component is "", "." or "..",
checked on the raw name before it is cleaned or joined on the prefix.
The zip archiver handed out its cached directory tree directly. Any
caller which filters a listing in place (as the core listing code
does) altered the cache, so later listings of the same directory could
be corrupted.
Return a copy of the cached listing instead.
Whether an archive entry name can escape the archive's namespace was
left entirely to each archiver. Enforce it in the archive backend too.
List only passes on direct children of the directory listed and
NewObject only returns the object asked for, so a future archiver
which forgets to validate names cannot expose a traversal to fs/sync
and fs/operations.
The path inside the archive was compared against the cleaned entry
names without being cleaned itself, so `archive.zip/sub/./dir` or
`archive.zip/sub//dir` failed to list even though `archive.zip/sub/dir`
worked.
A zip containing a file entry whose name refers to the archive's own
root (".", "/" or "") was presented as a single file called "." and
all its other entries disappeared. A file at the root can only be the
archive member the backend was pointed at, so with no root such an
entry is skipped like any other unsafe name.
Entry names read from a squashfs directory are not sanitized by
go-diskfs. The squashfs backend joined each leaf name onto its
directory to form the object's remote, so a crafted image could escape
its directory.
Use sanitize.Leaf to skip unsafe entries in List. A "\" is an
ordinary character in a file name on the systems squashfs images are
made on and in an rclone remote path, so it is deliberately not
rejected; making it safe for the destination is the destination
backend's job.
Skipped entries are logged at DEBUG with a single NOTICE count per
listing so a crafted image under a mount cannot flood the log.
When a zip archive was mounted at a subdirectory root, readZip used a bare
strings.HasPrefix to decide which entries fell inside the root. This
matched on a raw string prefix rather than a path boundary, so mounting
root "foo" also exposed sibling entries such as "foobar/..." with their
names left uncorrected.
Require a path boundary when filtering by root.
The zip backend mounts a zip file as a browsable Fs. Go's archive/zip
does not sanitize entry names, and readZip applied path.Clean but did
not reject a cleaned name that still pointed outside the archive. A
crafted zip could make rclone copy/sync attempt writes outside the
intended destination.
Sanitize entry names with sanitize.Path - the same check used by
rclone archive extract - skipping any entry with a ".." path
component, whether separated by "/" or "\". A backslash is otherwise
kept as an ordinary character in the name, as archive extract does. It
is up to the destination backend to make names safe for its storage.
Skipped entries are logged as a single count per archive so a crafted
archive with many escaping entries cannot flood the log.
The archive backend passes remote .sqfs bytes straight to the go-diskfs squashfs
parser, which does not validate several attacker-controlled superblock and
metadata fields. A crafted image can make the parser panic.
Recover panics at the go-diskfs boundary and return an "invalid or corrupt
squashfs image" error instead. As well as the parse entry points (Read, ReadDir,
OpenFile) this wraps the reader returned by Open, since the parser reads file
data lazily and can panic long after the image opened successfully.
Addresses GHSA-6jcg-q3wp-x2f4.
Bump go-diskfs to v1.9.4, which contains diskfs/go-diskfs#413 handling
squashfs images that have no fragment table or no xattr table. On v1.9.3
these images fail to list at all (ReadDir errors, or a nil xattr-table
dereference inside the library).
Adapt the backend to the v1.9.4 io/fs API: ReadDir now returns
io/fs.DirEntry (metadata via DirEntry.Info), and files are opened via
FileSystem.OpenFile instead of the removed FileStat.Open. The path
conversion added in c10eb47 (toIOFS) is reused.
Add a regression test with two committed fixtures built from trivial
placeholder content: an empty directory (no fragment table) and a small
tree whose superblock has the NO_XATTRS flag set while inodes still carry
an xattr index.
Fixes#9004
The go-diskfs library now requires io/fs.ValidPath style paths (no
leading slash, "." for the root) so convert paths at the library
boundary. This fixes listing failures and the resulting test hangs
after the update to go-diskfs v1.9.3.
This fixes the code to compile with the updated dependencies:
- squashfs: implement the new Path method required by the go-diskfs
backend.Storage interface, returning an empty string as there is no
underlying path.
- dropbox: convert to and from the SDK's new DBXTime type (an alias
for time.Time) for ClientModified, TimeInvited and Expires.
- dropbox: remove a stray debug fmt.Printf from the shared folder
listing.
- pin go-systemd to v22.6.0 to fix netbsd builds
go-systemd v22.7.0 uses unix.ClockGettime and unix.CLOCK_MONOTONIC
which golang.org/x/sys does not define for netbsd, so the build fails.
See: https://github.com/coreos/go-systemd/issues/512
- pin google.golang.org/grpc to v1.80.0 to fix plan9 builds
grpc v1.81.0 and later use syscall.Errno, syscall.ECONNRESET and
syscall.ECONNABORTED which do not exist on plan9, so the build fails
See: https://github.com/grpc/grpc-go/issues/9253
Add a ctx parameter to vfs.New() so callers can pass in context
carrying ConfigInfo and FilterInfo. The context is stripped of
cancellation but config and filter values are preserved into a fresh
background context.
Nick Craig-Wood
maximilizeandNick Craig-Wood