Go to file
Jeff King 7b70e9efb1 upload-pack: disable lazy-fetching by default
The upload-pack command tries to avoid trusting the repository in which
it's run (e.g., by not running any hooks and not using any config that
contains arbitrary commands). But if the server side of a fetch or a
clone is a partial clone, then either upload-pack or its child
pack-objects may run a lazy "git fetch" under the hood. And it is very
easy to convince fetch to run arbitrary commands.

The "server" side can be a local repository owned by someone else, who
would be able to configure commands that are run during a clone with the
current user's permissions. This issue has been designated
CVE-2024-32004.

The fix in this commit's parent helps in this scenario, as well as in
related scenarios using SSH to clone, where the untrusted .git directory
is owned by a different user id. But if you received one as a zip file,
on a USB stick, etc, it may be owned by your user but still untrusted.

This has been designated CVE-2024-32465.

To mitigate the issue more completely, let's disable lazy fetching
entirely during `upload-pack`. While fetching from a partial repository
should be relatively rare, it is certainly not an unreasonable workflow.
And thus we need to provide an escape hatch.

This commit works by respecting a GIT_NO_LAZY_FETCH environment variable
(to skip the lazy-fetch), and setting it in upload-pack, but only when
the user has not already done so (which gives us the escape hatch).

The name of the variable is specifically chosen to match what has
already been added in 'master' via e6d5479e7a (git: extend
--no-lazy-fetch to work across subprocesses, 2024-02-27). Since we're
building this fix as a backport for older versions, we could cherry-pick
that patch and its earlier steps. However, we don't really need the
niceties (like a "--no-lazy-fetch" option) that it offers. By using the
same name, everything should just work when the two are eventually
merged, but here are a few notes:

  - the blocking of the fetch in e6d5479e7a is incomplete! It sets
    fetch_if_missing to 0 when we setup the repository variable, but
    that isn't enough. pack-objects in particular will call
    prefetch_to_pack() even if that variable is 0. This patch by
    contrast checks the environment variable at the lowest level before
    we call the lazy fetch, where we can be sure to catch all code
    paths.

    Possibly the setting of fetch_if_missing from e6d5479e7a can be
    reverted, but it may be useful to have. For example, some code may
    want to use that flag to change behavior before it gets to the point
    of trying to start the fetch. At any rate, that's all outside the
    scope of this patch.

  - there's documentation for GIT_NO_LAZY_FETCH in e6d5479e7a. We can
    live without that here, because for the most part the user shouldn't
    need to set it themselves. The exception is if they do want to
    override upload-pack's default, and that requires a separate
    documentation section (which is added here)

  - it would be nice to use the NO_LAZY_FETCH_ENVIRONMENT macro added by
    e6d5479e7a, but those definitions have moved from cache.h to
    environment.h between 2.39.3 and master. I just used the raw string
    literals, and we can replace them with the macro once this topic is
    merged to master.

At least with respect to CVE-2024-32004, this does render this commit's
parent commit somewhat redundant. However, it is worth retaining that
commit as defense in depth, and because it may help other issues (e.g.,
symlink/hardlink TOCTOU races, where zip files are not really an
interesting attack vector).

The tests in t0411 still pass, but now we have _two_ mechanisms ensuring
that the evil command is not run. Let's beef up the existing ones to
check that they failed for the expected reason, that we refused to run
upload-pack at all with an alternate user id. And add two new ones for
the same-user case that both the restriction and its escape hatch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:29:56 +02:00
.github ci(linux32): add a note about Actions that must not be updated 2024-04-17 00:00:58 +02:00
Documentation upload-pack: disable lazy-fetching by default 2024-04-17 22:29:56 +02:00
block-sha1
builtin upload-pack: disable lazy-fetching by default 2024-04-17 22:29:56 +02:00
ci Merge branch 'quicker-asan-lsan' 2024-04-17 00:00:56 +02:00
compat Merge branch 'jh/fsmonitor-darwin-modernize' 2024-04-16 23:55:55 +02:00
contrib Merge branch 'ab/fewer-the-index-macros' 2022-12-01 18:38:07 +09:00
ewah
git-gui Makefiles: change search through $(MAKEFLAGS) for GNU make 4.4 2022-12-01 07:24:12 +09:00
gitk-git
gitweb
mergetools
negotiator
oss-fuzz
perl
po l10n: zh_TW.po: Git 2.39-rc2 2022-12-11 01:27:25 +08:00
refs Merge branch 'ps/fsync-refs-fix' into maint-2.39 2023-02-14 14:15:50 -08:00
reftable
sha1collisiondetection@855827c583
sha1dc
sha256
t upload-pack: disable lazy-fetching by default 2024-04-17 22:29:56 +02:00
templates
trace2
xdiff xdiff: mark unused parameter in xdl_call_hunk_func() 2022-12-13 22:16:23 +09:00
.cirrus.yml
.clang-format
.editorconfig
.gitattributes
.gitignore Merge branch 'ab/coccicheck-incremental' 2022-11-23 11:22:23 +09:00
.gitmodules
.mailmap mailmap: update email address of Matheus Tavares 2022-12-10 09:17:36 +09:00
.tsan-suppressions
CODE_OF_CONDUCT.md
COPYING
GIT-VERSION-GEN Git 2.39.3 2023-04-17 21:16:08 +02:00
INSTALL Merge branch 'backport/jk/libcurl-8.7-regression-workaround' into maint-2.39 2024-04-16 23:58:53 +02:00
LGPL-2.1
Makefile Sync with 2.36.6 2023-04-17 21:16:04 +02:00
README.md
RelNotes Git 2.38.5 2023-04-17 21:16:07 +02:00
SECURITY.md
abspath.c
aclocal.m4
add-interactive.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
add-interactive.h
add-patch.c read-cache API & users: make discard_index() return void 2022-11-21 12:06:15 +09:00
advice.c
advice.h
alias.c
alias.h
alloc.c
alloc.h
apply.c Sync with 2.38.5 2023-04-17 21:16:08 +02:00
apply.h
archive-tar.c
archive-zip.c
archive.c
archive.h
attr.c Sync with maint-2.37 2023-01-19 13:48:26 -08:00
attr.h Merge branch 'maint-2.35' into maint-2.36 2022-12-13 21:19:11 +09:00
banned.h
base85.c
bisect.c
bisect.h
blame.c
blame.h
blob.c blob: drop unused parts of parse_blob_buffer() 2022-12-13 22:16:22 +09:00
blob.h blob: drop unused parts of parse_blob_buffer() 2022-12-13 22:16:22 +09:00
bloom.c
bloom.h
branch.c
branch.h
builtin.h
bulk-checkin.c
bulk-checkin.h
bundle-uri.c
bundle-uri.h
bundle.c
bundle.h
cache-tree.c
cache-tree.h
cache.h fetch/clone: detect dubious ownership of local repositories 2024-04-17 22:29:54 +02:00
cbtree.c
cbtree.h
chdir-notify.c
chdir-notify.h
check-builtins.sh
checkout.c
checkout.h
chunk-format.c
chunk-format.h
color.c
color.h
column.c utf8: fix truncated string lengths in `utf8_strnwidth()` 2022-12-09 14:26:21 +09:00
column.h
combine-diff.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
command-list.txt
commit-graph.c
commit-graph.h
commit-reach.c
commit-reach.h
commit-slab-decl.h
commit-slab-impl.h
commit-slab.h
commit.c Merge branch 'rs/clear-commit-marks-cleanup' into maint-2.39 2023-02-14 14:15:56 -08:00
commit.h
common-main.c
config.c Sync with 2.38.5 2023-04-17 21:16:08 +02:00
config.h
config.mak.dev
config.mak.in
config.mak.uname use enhanced basic regular expressions on macOS 2023-01-08 10:06:34 +09:00
configure.ac
connect.c server_supports_v2(): use a separate function for die_on_error 2022-12-13 22:08:52 +09:00
connect.h server_supports_v2(): use a separate function for die_on_error 2022-12-13 22:08:52 +09:00
connected.c receive-pack: only use visible refs for connectivity check 2022-11-17 16:22:52 -05:00
connected.h receive-pack: only use visible refs for connectivity check 2022-11-17 16:22:52 -05:00
convert.c
convert.h
copy.c
credential.c
credential.h
csum-file.c
csum-file.h
ctype.c
daemon.c
date.c
date.h
decorate.c
decorate.h
delta-islands.c delta-islands: free island-related data after use 2022-11-18 18:30:49 -05:00
delta-islands.h
delta.h
detect-compiler
diagnose.c
diagnose.h
diff-delta.c
diff-lib.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
diff-merges.c
diff-merges.h
diff-no-index.c
diff.c Merge branch 'jk/unused-post-2.39' into maint-2.39 2023-02-14 14:15:55 -08:00
diff.h
diffcore-break.c
diffcore-delta.c
diffcore-order.c
diffcore-pickaxe.c
diffcore-rename.c
diffcore-rotate.c
diffcore.h
dir-iterator.c dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS 2023-01-24 16:52:16 -08:00
dir-iterator.h dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS 2023-01-24 16:52:16 -08:00
dir.c Sync with 2.34.8 2023-04-17 21:15:59 +02:00
dir.h
editor.c
entry.c
entry.h
environment.c
environment.h
exec-cmd.c
exec-cmd.h
fetch-negotiator.c
fetch-negotiator.h
fetch-pack.c server_supports_v2(): use a separate function for die_on_error 2022-12-13 22:08:52 +09:00
fetch-pack.h
fmt-merge-msg.c
fmt-merge-msg.h
fsck.c Merge branch 'maint-2.36' into maint-2.37 2022-12-13 21:20:35 +09:00
fsck.h Sync with 2.38.3 2022-12-13 21:25:15 +09:00
fsmonitor--daemon.h
fsmonitor-ipc.c
fsmonitor-ipc.h
fsmonitor-path-utils.h
fsmonitor-settings.c
fsmonitor-settings.h
fsmonitor.c
fsmonitor.h
generate-cmdlist.sh
generate-configlist.sh
generate-hooklist.sh
gettext.c Sync with 2.38.5 2023-04-17 21:16:08 +02:00
gettext.h Sync with 2.33.8 2023-04-17 21:15:56 +02:00
git-add--interactive.perl
git-archimport.perl
git-bisect.sh bisect--helper: parse subcommand with OPT_SUBCOMMAND 2022-11-11 17:04:57 -05:00
git-compat-util.h Merge branch 'rs/use-enhanced-bre-on-macos' into maint-2.39 2023-02-14 14:15:49 -08:00
git-curl-compat.h remote-curl: add Transfer-Encoding header only for older curl 2024-04-10 19:24:48 +02:00
git-cvsexportcommit.perl
git-cvsimport.perl
git-cvsserver.perl
git-difftool--helper.sh
git-filter-branch.sh
git-instaweb.sh
git-merge-octopus.sh
git-merge-one-file.sh
git-merge-resolve.sh
git-mergetool--lib.sh
git-mergetool.sh
git-p4.py
git-quiltimport.sh
git-request-pull.sh
git-send-email.perl
git-sh-i18n.sh
git-sh-setup.sh
git-submodule.sh
git-svn.perl
git-web--browse.sh
git.c Merge branch 'ab/submodule-helper-prep-only' 2022-11-23 11:22:22 +09:00
git.rc
gpg-interface.c
gpg-interface.h
graph.c
graph.h
grep.c
grep.h
hash-lookup.c
hash-lookup.h
hash.h
hashmap.c
hashmap.h
help.c
help.h
hex.c
hook.c
hook.h
http-backend.c
http-fetch.c
http-push.c Sync with 2.31.8 2023-04-17 21:15:49 +02:00
http-walker.c
http.c Merge branch 'backport/jk/libcurl-8.7-regression-workaround' into maint-2.39 2024-04-16 23:58:53 +02:00
http.h Sync with 2.30.9 2023-04-17 21:15:44 +02:00
ident.c
imap-send.c
iterator.h
json-writer.c
json-writer.h
khash.h
kwset.c
kwset.h
levenshtein.c
levenshtein.h
line-log.c
line-log.h
line-range.c line-range: fix infinite loop bug with '$' regex 2022-12-20 10:00:43 +09:00
line-range.h
linear-assignment.c
linear-assignment.h
list-objects-filter-options.c
list-objects-filter-options.h
list-objects-filter.c Merge branch 'jk/unused-post-2.39' into maint-2.39 2023-02-14 14:15:55 -08:00
list-objects-filter.h
list-objects.c list-objects: drop process_gitlink() function 2022-12-13 22:16:22 +09:00
list-objects.h
list.h
ll-merge.c
ll-merge.h
lockfile.c
lockfile.h
log-tree.c
log-tree.h
ls-refs.c ls-refs: use repository parameter to iterate refs 2022-12-13 22:16:22 +09:00
ls-refs.h
mailinfo.c
mailinfo.h
mailmap.c
mailmap.h
match-trees.c
mem-pool.c
mem-pool.h
merge-blobs.c
merge-blobs.h
merge-ort-wrappers.c
merge-ort-wrappers.h
merge-ort.c
merge-ort.h
merge-recursive.c merge-recursive: fix variable typo in error message 2022-11-27 10:26:10 +09:00
merge-recursive.h
merge.c
mergesort.h
midx.c
midx.h
name-hash.c
notes-cache.c
notes-cache.h
notes-merge.c
notes-merge.h
notes-utils.c
notes-utils.h
notes.c
notes.h
object-file.c object-file: inline write_buffer() 2022-12-14 10:29:19 +09:00
object-name.c
object-store.h
object.c blob: drop unused parts of parse_blob_buffer() 2022-12-13 22:16:22 +09:00
object.h
oid-array.c
oid-array.h
oidmap.c
oidmap.h
oidset.c
oidset.h
oidtree.c
oidtree.h
pack-bitmap-write.c
pack-bitmap.c
pack-bitmap.h
pack-check.c
pack-mtimes.c
pack-mtimes.h
pack-objects.c
pack-objects.h
pack-revindex.c
pack-revindex.h
pack-write.c git: remove duplicate includes 2022-12-15 09:09:38 +09:00
pack.h
packfile.c
packfile.h
pager.c
parallel-checkout.c
parallel-checkout.h
parse-options-cb.c
parse-options.c
parse-options.h
patch-delta.c
patch-ids.c
patch-ids.h
path.c fetch/clone: detect dubious ownership of local repositories 2024-04-17 22:29:54 +02:00
path.h
pathspec.c
pathspec.h
pkt-line.c
pkt-line.h
preload-index.c
pretty.c Sync with Git 2.37.5 2022-12-13 21:23:36 +09:00
pretty.h
prio-queue.c
prio-queue.h
progress.c
progress.h
promisor-remote.c upload-pack: disable lazy-fetching by default 2024-04-17 22:29:56 +02:00
promisor-remote.h
prompt.c
prompt.h
protocol-caps.c
protocol-caps.h
protocol.c
protocol.h
prune-packed.c
prune-packed.h
quote.c
quote.h
range-diff.c Sync with 2.31.8 2023-04-17 21:15:49 +02:00
range-diff.h
reachable.c
reachable.h
read-cache.c read-cache API & users: make discard_index() return void 2022-11-21 12:06:15 +09:00
rebase-interactive.c
rebase-interactive.h
rebase.c
rebase.h
ref-filter.c ls-refs: use repository parameter to iterate refs 2022-12-13 22:16:22 +09:00
ref-filter.h
reflog-walk.c
reflog-walk.h
reflog.c Merge branch 'rs/reflog-expiry-cleanup' into maint-2.39 2023-02-14 14:15:56 -08:00
reflog.h
refs.c ls-refs: use repository parameter to iterate refs 2022-12-13 22:16:22 +09:00
refs.h ls-refs: use repository parameter to iterate refs 2022-12-13 22:16:22 +09:00
refspec.c
refspec.h
remote-curl.c Merge branch 'backport/jk/libcurl-8.7-regression-workaround' into maint-2.39 2024-04-16 23:58:53 +02:00
remote.c
remote.h
replace-object.c
replace-object.h
repo-settings.c
repository.c {builtin/*,repository}.c: add & use "USE_THE_INDEX_VARIABLE" 2022-11-21 12:06:15 +09:00
repository.h
rerere.c
rerere.h
reset.c rebase: use 'skip_cache_tree_update' option 2022-11-10 21:49:34 -05:00
reset.h
resolve-undo.c
resolve-undo.h
revision.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
revision.h Merge branch 'ps/receive-use-only-advertised' 2022-11-23 11:22:25 +09:00
run-command.c
run-command.h
scalar.c Merge branch 'js/remove-stale-scalar-repos' 2022-11-23 11:22:23 +09:00
send-pack.c
send-pack.h
sequencer.c git: remove duplicate includes 2022-12-15 09:09:38 +09:00
sequencer.h sequencer: stop exporting GIT_REFLOG_ACTION 2022-11-09 18:15:43 -05:00
serve.c
serve.h
server-info.c
setup.c fetch/clone: detect dubious ownership of local repositories 2024-04-17 22:29:54 +02:00
sh-i18n--envsubst.c
sha1dc_git.c
sha1dc_git.h
shallow.c
shallow.h
shared.mak Merge branch 'ab/gnumake-4.4-fix' 2022-12-01 18:38:07 +09:00
shell.c
shortlog.h
sideband.c
sideband.h
sigchain.c
sigchain.h
simple-ipc.h
sparse-index.c
sparse-index.h
split-index.c
split-index.h
stable-qsort.c
strbuf.c
strbuf.h
streaming.c
streaming.h
string-list.c
string-list.h
strmap.c
strmap.h
strvec.c
strvec.h
sub-process.c
sub-process.h
submodule-config.c
submodule-config.h
submodule.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
submodule.h
symlinks.c
tag.c
tag.h
tar.h
tempfile.c
tempfile.h
thread-utils.c
thread-utils.h
tmp-objdir.c
tmp-objdir.h
trace.c
trace.h
trace2.c
trace2.h
trailer.c
trailer.h
transport-helper.c
transport-internal.h
transport.c
transport.h
tree-diff.c
tree-walk.c
tree-walk.h
tree.c
tree.h
unicode-width.h
unimplemented.sh
unix-socket.c
unix-socket.h
unix-stream-server.c
unix-stream-server.h
unpack-trees.c git: remove duplicate includes 2022-12-15 09:09:38 +09:00
unpack-trees.h unpack-trees: add 'skip_cache_tree_update' option 2022-11-10 21:49:34 -05:00
upload-pack.c refs: get rid of global list of hidden refs 2022-11-17 16:22:51 -05:00
upload-pack.h
url.c
url.h
urlmatch.c
urlmatch.h
usage.c
userdiff.c userdiff: mark unused parameter in internal callback 2022-12-13 22:16:23 +09:00
userdiff.h
utf8.c Sync with Git 2.31.6 2022-12-13 21:09:40 +09:00
utf8.h Sync with Git 2.31.6 2022-12-13 21:09:40 +09:00
varint.c
varint.h
version.c
version.h
versioncmp.c
walker.c
walker.h
wildmatch.c
wildmatch.h
worktree.c
worktree.h
wrap-for-bin.sh
wrapper.c
write-or-die.c
ws.c ws: drop unused parameter from ws_blank_line() 2022-12-13 22:16:23 +09:00
wt-status.c diff: mark unused parameters in callbacks 2022-12-13 22:16:23 +09:00
wt-status.h
xdiff-interface.c
xdiff-interface.h
zlib.c

README.md

Build status

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-<commandname>.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).

Those wishing to help with error message, usage and informational message string translations (localization l10) should see po/README.md (a po file is a Portable Object file that holds the translations).

To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.

Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.

The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • "goddamn idiotic truckload of sh*t": when it breaks