testsuid/README.md

testsuid

This program is a simple git wrapper intended to be used with suid/guid bits set to "impersonate" another user and let them clone a repository (with their consent, of course).

When cloning the repository without initializing the submodules, everything works as expected. However, it appears git fails when cloning submodules when called from a suid program (the program uses git clone --recursive).

How to reproduce:

$ git clone https://tildegit.org/southerntofu/testsuid
$ cd testsuid
$ cargo build --release
$ cp target/release/testsuid /tmp/testsuid
$ chmod u+s,g+s /tmp/testsuid
$ mkdir /tmp/dest/
$ /tmp/testsuid "https://tildegit.org/tilde-fr/site" /tmp/dest/1
Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/1 (recursive: false)
$ # SUCCESS
$ /tmp/testsuid --recursive "https://tildegit.org/tilde-fr/site" /tmp/dest/2
Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/2 (recursive: true)
$ # SUCCESS
$ # Now let's try from a different user.
$ su guest
$ /tmp/testsuid "https://tildegit.org/tilde-fr/site" /tmp/dest/3
Cloning https://tildegit.org/tilde-fr/site to /tmp/dest3 (recursive: false)
$ # SUCCESS
$ /tmp/testsuid --recursive "https://tildegit.org/tilde-fr/site" /tmp/dest/4
Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/4 (recursive: true)
FAILED!
STDOUT:

STDERR:
18:24:38.064467 git.c:418               trace: built-in: git clone --recursive https://tildegit.org/tilde-fr/site /tmp/dest/4
Cloning into '/tmp/dest/4'...
18:24:38.070170 run-command.c:643       trace: run_command: git-remote-https origin https://tildegit.org/tilde-fr/site
18:24:38.621635 run-command.c:643       trace: run_command: git fetch-pack --stateless-rpc --stdin --lock-pack --thin --check-self-contained-and-connected --cloning --no-progress https://tildegit.org/tilde-fr/site/
18:24:38.625704 git.c:418               trace: built-in: git fetch-pack --stateless-rpc --stdin --lock-pack --thin --check-self-contained-and-connected --cloning --no-progress https://tildegit.org/tilde-fr/site/
18:24:38.820744 run-command.c:643       trace: run_command: git unpack-objects -q --pack_header=2,60
18:24:38.823934 git.c:418               trace: built-in: git unpack-objects -q --pack_header=2,60
18:24:38.840025 run-command.c:643       trace: run_command: git rev-list --objects --stdin --not --all --quiet
18:24:38.841075 git.c:418               trace: built-in: git rev-list --objects --stdin --not --all --quiet
warning: unable to access '/home/guest/.config/git/attributes': Permission denied
18:24:38.848734 run-command.c:643       trace: run_command: git submodule update --require-init --recursive
18:24:38.849745 git.c:669               trace: exec: git-submodule update --require-init --recursive
18:24:38.849789 run-command.c:643       trace: run_command: git-submodule update --require-init --recursive
18:24:38.857209 git.c:418               trace: built-in: git rev-parse --git-dir
18:24:38.858398 git.c:418               trace: built-in: git rev-parse --git-path objects
18:24:38.859289 git.c:418               trace: built-in: git rev-parse -q --git-dir
18:24:38.861442 git.c:418               trace: built-in: git rev-parse --show-prefix
18:24:38.862713 git.c:418               trace: built-in: git rev-parse --show-toplevel
18:24:38.864570 git.c:418               trace: built-in: git submodule--helper init
error: could not lock config file /tmp/dest/4/.git/config: Permission denied
fatal: Failed to register url for submodule path 'themes/water'