mirror of
https://github.com/git/git
synced 2024-09-17 23:41:33 +00:00
e1d911dd4c
The backslash character is not a valid part of a file name on Windows. Hence it is dangerous to allow writing files that were unpacked from tree objects, when the stored file name contains a backslash character: it will be misinterpreted as directory separator. This not only causes ambiguity when a tree contains a blob `a\b` and a tree `a` that contains a blob `b`, but it also can be used as part of an attack vector to side-step the careful protections against writing into the `.git/` directory during a clone of a maliciously-crafted repository. Let's prevent that, addressing CVE-2019-1354. Note: we guard against backslash characters in tree objects' file names _only_ on Windows (because on other platforms, even on those where NTFS volumes can be mounted, the backslash character is _not_ a directory separator), and _only_ when `core.protectNTFS = true` (because users might need to generate tree objects for other platforms, of course without touching the worktree, e.g. using `git update-index --cacheinfo`). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
110 lines
2.9 KiB
Bash
Executable file
110 lines
2.9 KiB
Bash
Executable file
#!/bin/sh
|
|
|
|
test_description='check handling of .. in submodule names
|
|
|
|
Exercise the name-checking function on a variety of names, and then give a
|
|
real-world setup that confirms we catch this in practice.
|
|
'
|
|
. ./test-lib.sh
|
|
|
|
test_expect_success 'check names' '
|
|
cat >expect <<-\EOF &&
|
|
valid
|
|
valid/with/paths
|
|
EOF
|
|
|
|
git submodule--helper check-name >actual <<-\EOF &&
|
|
valid
|
|
valid/with/paths
|
|
|
|
../foo
|
|
/../foo
|
|
..\foo
|
|
\..\foo
|
|
foo/..
|
|
foo/../
|
|
foo\..
|
|
foo\..\
|
|
foo/../bar
|
|
EOF
|
|
|
|
test_cmp expect actual
|
|
'
|
|
|
|
test_expect_success 'create innocent subrepo' '
|
|
git init innocent &&
|
|
git -C innocent commit --allow-empty -m foo
|
|
'
|
|
|
|
test_expect_success 'submodule add refuses invalid names' '
|
|
test_must_fail \
|
|
git submodule add --name ../../modules/evil "$PWD/innocent" evil
|
|
'
|
|
|
|
test_expect_success 'add evil submodule' '
|
|
git submodule add "$PWD/innocent" evil &&
|
|
|
|
mkdir modules &&
|
|
cp -r .git/modules/evil modules &&
|
|
write_script modules/evil/hooks/post-checkout <<-\EOF &&
|
|
echo >&2 "RUNNING POST CHECKOUT"
|
|
EOF
|
|
|
|
git config -f .gitmodules submodule.evil.update checkout &&
|
|
git config -f .gitmodules --rename-section \
|
|
submodule.evil submodule.../../modules/evil &&
|
|
git add modules &&
|
|
git commit -am evil
|
|
'
|
|
|
|
# This step seems like it shouldn't be necessary, since the payload is
|
|
# contained entirely in the evil submodule. But due to the vagaries of the
|
|
# submodule code, checking out the evil module will fail unless ".git/modules"
|
|
# exists. Adding another submodule (with a name that sorts before "evil") is an
|
|
# easy way to make sure this is the case in the victim clone.
|
|
test_expect_success 'add other submodule' '
|
|
git submodule add "$PWD/innocent" another-module &&
|
|
git add another-module &&
|
|
git commit -am another
|
|
'
|
|
|
|
test_expect_success 'clone evil superproject' '
|
|
git clone --recurse-submodules . victim >output 2>&1 &&
|
|
! grep "RUNNING POST CHECKOUT" output
|
|
'
|
|
|
|
test_expect_success MINGW 'prevent git~1 squatting on Windows' '
|
|
git init squatting &&
|
|
(
|
|
cd squatting &&
|
|
mkdir a &&
|
|
touch a/..git &&
|
|
git add a/..git &&
|
|
test_tick &&
|
|
git commit -m initial &&
|
|
|
|
modules="$(test_write_lines \
|
|
"[submodule \"b.\"]" "url = ." "path = c" \
|
|
"[submodule \"b\"]" "url = ." "path = d\\\\a" |
|
|
git hash-object -w --stdin)" &&
|
|
rev="$(git rev-parse --verify HEAD)" &&
|
|
hash="$(echo x | git hash-object -w --stdin)" &&
|
|
git -c core.protectNTFS=false update-index --add \
|
|
--cacheinfo 100644,$modules,.gitmodules \
|
|
--cacheinfo 160000,$rev,c \
|
|
--cacheinfo 160000,$rev,d\\a \
|
|
--cacheinfo 100644,$hash,d./a/x \
|
|
--cacheinfo 100644,$hash,d./a/..git &&
|
|
test_tick &&
|
|
git -c core.protectNTFS=false commit -m "module" &&
|
|
test_must_fail git show HEAD: 2>err &&
|
|
test_i18ngrep backslash err
|
|
) &&
|
|
test_must_fail git -c core.protectNTFS=false \
|
|
clone --recurse-submodules squatting squatting-clone 2>err &&
|
|
test_i18ngrep "directory not empty" err &&
|
|
! grep gitdir squatting-clone/d/a/git~2
|
|
'
|
|
|
|
test_done
|