t0034: add negative tests and allow git init to mostly work under sudo

Add a support library that provides one function that can be used
to run a "scriplet" of commands through sudo and that helps invoking
sudo in the slightly awkward way that is required to ensure it doesn't
block the call (if shell was allowed as tested in the prerequisite)
and it doesn't run the command through a different shell than the one
we intended.

Add additional negative tests as suggested by Junio and that use a
new workspace that is owned by root.

Document a regression that was introduced by previous commits where
root won't be able anymore to access directories they own unless
SUDO_UID is removed from their environment.

The tests document additional ways that this new restriction could
be worked around and the documentation explains why it might be instead
considered a feature, but a "fix" is planned for a future change.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Carlo Marcelo Arenas Belón 2022-05-12 18:00:19 -07:00 committed by Junio C Hamano
parent ae9abbb63e
commit b9063afda1
2 changed files with 77 additions and 0 deletions

15
t/lib-sudo.sh Normal file
View File

@ -0,0 +1,15 @@
# Helpers for running git commands under sudo.
# Runs a scriplet passed through stdin under sudo.
run_with_sudo () {
local ret
local RUN="$TEST_DIRECTORY/$$.sh"
write_script "$RUN" "$TEST_SHELL_PATH"
# avoid calling "$RUN" directly so sudo doesn't get a chance to
# override the shell, add aditional restrictions or even reject
# running the script because its security policy deem it unsafe
sudo "$TEST_SHELL_PATH" -c "\"$RUN\""
ret=$?
rm -f "$RUN"
return $ret
}

View File

@ -3,6 +3,7 @@
test_description='verify safe.directory checks while running as root'
. ./test-lib.sh
. "$TEST_DIRECTORY"/lib-sudo.sh
if [ "$GIT_TEST_ALLOW_SUDO" != "YES" ]
then
@ -10,6 +11,12 @@ then
test_done
fi
if ! test_have_prereq NOT_ROOT
then
skip_all="These tests do not support running as root"
test_done
fi
test_lazy_prereq SUDO '
sudo -n id -u >u &&
id -u root >r &&
@ -19,6 +26,12 @@ test_lazy_prereq SUDO '
test_cmp u r
'
if ! test_have_prereq SUDO
then
skip_all="Your sudo/system configuration is either too strict or unsupported"
test_done
fi
test_expect_success SUDO 'setup' '
sudo rm -rf root &&
mkdir -p root/r &&
@ -36,6 +49,55 @@ test_expect_success SUDO 'sudo git status as original owner' '
)
'
test_expect_success SUDO 'setup root owned repository' '
sudo mkdir -p root/p &&
sudo git init root/p
'
test_expect_success 'cannot access if owned by root' '
(
cd root/p &&
test_must_fail git status
)
'
test_expect_success 'can access if addressed explicitly' '
(
cd root/p &&
GIT_DIR=.git GIT_WORK_TREE=. git status
)
'
test_expect_failure SUDO 'can access with sudo if root' '
(
cd root/p &&
sudo git status
)
'
test_expect_success SUDO 'can access with sudo if root by removing SUDO_UID' '
(
cd root/p &&
run_with_sudo <<-END
unset SUDO_UID &&
git status
END
)
'
test_lazy_prereq SUDO_SUDO '
sudo sudo id -u >u &&
id -u root >r &&
test_cmp u r
'
test_expect_success SUDO_SUDO 'can access with sudo abusing SUDO_UID' '
(
cd root/p &&
sudo sudo git status
)
'
# this MUST be always the last test
test_expect_success SUDO 'cleanup' '
sudo rm -rf root