Re: [PATCH v2] list-objects-filter: disable 'sparse:path' filters
- Date: Tue, 28 May 2019 12:41:58 -0700
- From: Junio C Hamano <gitster@xxxxxxxxx>
- Subject: Re: [PATCH v2] list-objects-filter: disable 'sparse:path' filters
Christian Couder <christian.couder@xxxxxxxxx> writes:
> If someone wants to use as a filter a sparse file that is in the
> repository, something like "--filter=sparse:oid=<ref>:<path>"
> already works.
> So 'sparse:path' is only interesting if the sparse file is not in
> the repository. In this case though the current implementation has
> a big security issue, as it makes it possible to ask the server to
> read any file, like for example /etc/password, and to explore the
> filesystem, as well as individual lines of files.
> If someone is interested in using a sparse file that is not in the
> repository as a filter, then at the minimum a config option, such
> as "uploadpack.sparsePathFilter", should be implemented first to
> restrict the directory from which the files specified by
> 'sparse:path' can be read.
> For now though, let's just disable 'sparse:path' filters.
> Helped-by: Matthew DeVore <matvore@xxxxxxxxxx>
> Helped-by: Jeff Hostetler <git@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Christian Couder <chriscool@xxxxxxxxxxxxx>
> Changes since the RFC version are the following:
> - improved the error message when 'sparse:path' is used,
> - updated "git-completion.bash",
> - freed "sparse_path_value" field in list_objects_filter_release(),
> - updated tests (t5317 and t6112).
> Thanks to Matthew and Jeff for the suggestions.
> contrib/completion/git-completion.bash | 2 +-
> list-objects-filter-options.c | 10 ++--
> list-objects-filter-options.h | 2 -
> list-objects-filter.c | 22 --------
> t/t5317-pack-objects-filter-objects.sh | 71 +++++---------------------
> t/t6112-rev-list-filters-objects.sh | 39 +++++---------
> 6 files changed, 33 insertions(+), 113 deletions(-)
What is curious is that this does not touch Documentation/ hierarchy
at all---is that a sign that nobody makes any serious use of the
--filter=... thing and we can freely drop "features" around it when
we see it necessary (like in this case)?
Or do we need something like this on top (or squashed in)? I can
live with or without "Note that..." myself.
Documentation/rev-list-options.txt | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index ddbc1de43f..73aafea8d6 100644
@@ -725,9 +725,6 @@ specification contained in the blob (or blob-expression) '<blob-ish>'
to omit blobs that would not be not required for a sparse checkout on
the requested refs.
-The form '--filter=sparse:path=<path>' similarly uses a sparse-checkout
-specification contained in <path>.
The form '--filter=tree:<depth>' omits all blobs and trees whose depth
from the root tree is >= <depth> (minimum depth if an object is located
at multiple depths in the commits traversed). <depth>=0 will not include
@@ -737,6 +734,9 @@ tree and blobs which are referenced directly by a commit reachable from
<commit> or an explicitly-given object. <depth>=2 is like <depth>=1
while also including trees and blobs one more level removed from an
explicitly-given commit or tree.
+Note that the form '--filter=sparse:path=<path>' that wants to read from
+an arbitrary path on the filesystem is not supported, for security reasons.
Turn off any previous `--filter=` argument.