Sync with 2.31.7
* maint-2.31:
Git 2.31.7
Git 2.30.8
apply: fix writing behind newly created symbolic links
dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
clone: delay picking a transport until after get_repo_path()
t5619: demonstrate clone_local() with ambiguous transport
diff --git a/Documentation/RelNotes/2.30.8.txt b/Documentation/RelNotes/2.30.8.txt
new file mode 100644
index 0000000..38c23e0
--- /dev/null
+++ b/Documentation/RelNotes/2.30.8.txt
@@ -0,0 +1,52 @@
+Git v2.30.8 Release Notes
+=========================
+
+This release addresses the security issues CVE-2023-22490 and
+CVE-2023-23946.
+
+
+Fixes since v2.30.7
+-------------------
+
+ * CVE-2023-22490:
+
+ Using a specially-crafted repository, Git can be tricked into using
+ its local clone optimization even when using a non-local transport.
+ Though Git will abort local clones whose source $GIT_DIR/objects
+ directory contains symbolic links (c.f., CVE-2022-39253), the objects
+ directory itself may still be a symbolic link.
+
+ These two may be combined to include arbitrary files based on known
+ paths on the victim's filesystem within the malicious repository's
+ working copy, allowing for data exfiltration in a similar manner as
+ CVE-2022-39253.
+
+ * CVE-2023-23946:
+
+ By feeding a crafted input to "git apply", a path outside the
+ working tree can be overwritten as the user who is running "git
+ apply".
+
+ * A mismatched type in `attr.c::read_attr_from_index()` which could
+ cause Git to errantly reject attributes on Windows and 32-bit Linux
+ has been corrected.
+
+Credit for finding CVE-2023-22490 goes to yvvdwf, and the fix was
+developed by Taylor Blau, with additional help from others on the
+Git security mailing list.
+
+Credit for finding CVE-2023-23946 goes to Joern Schneeweisz, and the
+fix was developed by Patrick Steinhardt.
+
+
+Johannes Schindelin (1):
+ attr: adjust a mismatched data type
+
+Patrick Steinhardt (1):
+ apply: fix writing behind newly created symbolic links
+
+Taylor Blau (3):
+ t5619: demonstrate clone_local() with ambiguous transport
+ clone: delay picking a transport until after get_repo_path()
+ dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
+
diff --git a/Documentation/RelNotes/2.31.7.txt b/Documentation/RelNotes/2.31.7.txt
new file mode 100644
index 0000000..dd44d5b
--- /dev/null
+++ b/Documentation/RelNotes/2.31.7.txt
@@ -0,0 +1,6 @@
+Git v2.31.7 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.30.8 to
+address the security issues CVE-2023-22490 and CVE-2023-23946;
+see the release notes for that version for details.
diff --git a/apply.c b/apply.c
index 853d3ed..f562f79 100644
--- a/apply.c
+++ b/apply.c
@@ -4402,6 +4402,33 @@
if (state->cached)
return 0;
+ /*
+ * We already try to detect whether files are beyond a symlink in our
+ * up-front checks. But in the case where symlinks are created by any
+ * of the intermediate hunks it can happen that our up-front checks
+ * didn't yet see the symlink, but at the point of arriving here there
+ * in fact is one. We thus repeat the check for symlinks here.
+ *
+ * Note that this does not make the up-front check obsolete as the
+ * failure mode is different:
+ *
+ * - The up-front checks cause us to abort before we have written
+ * anything into the working directory. So when we exit this way the
+ * working directory remains clean.
+ *
+ * - The checks here happen in the middle of the action where we have
+ * already started to apply the patch. The end result will be a dirty
+ * working directory.
+ *
+ * Ideally, we should update the up-front checks to catch what would
+ * happen when we apply the patch before we damage the working tree.
+ * We have all the information necessary to do so. But for now, as a
+ * part of embargoed security work, having this check would serve as a
+ * reasonable first step.
+ */
+ if (path_is_beyond_symlink(state, path))
+ return error(_("affected file '%s' is beyond a symbolic link"), path);
+
res = try_create_file(state, path, mode, buf, size);
if (res < 0)
return -1;
diff --git a/builtin/clone.c b/builtin/clone.c
index cdf9208..97de324 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1220,10 +1220,6 @@
refspec_appendf(&remote->fetch, "+%s*:%s*", src_ref_prefix,
branch_top.buf);
- transport = transport_get(remote, remote->url[0]);
- transport_set_verbosity(transport, option_verbosity, option_progress);
- transport->family = family;
-
path = get_repo_path(remote->url[0], &is_bundle);
is_local = option_local != 0 && path && !is_bundle;
if (is_local) {
@@ -1245,6 +1241,10 @@
}
if (option_local > 0 && !is_local)
warning(_("--local is ignored"));
+
+ transport = transport_get(remote, path ? path : remote->url[0]);
+ transport_set_verbosity(transport, option_verbosity, option_progress);
+ transport->family = family;
transport->cloning = 1;
transport_set_option(transport, TRANS_OPT_KEEP, "yes");
diff --git a/dir-iterator.c b/dir-iterator.c
index b17e9f9..3764dd8 100644
--- a/dir-iterator.c
+++ b/dir-iterator.c
@@ -203,7 +203,7 @@
{
struct dir_iterator_int *iter = xcalloc(1, sizeof(*iter));
struct dir_iterator *dir_iterator = &iter->base;
- int saved_errno;
+ int saved_errno, err;
strbuf_init(&iter->base.path, PATH_MAX);
strbuf_addstr(&iter->base.path, path);
@@ -213,10 +213,15 @@
iter->flags = flags;
/*
- * Note: stat already checks for NULL or empty strings and
- * inexistent paths.
+ * Note: stat/lstat already checks for NULL or empty strings and
+ * nonexistent paths.
*/
- if (stat(iter->base.path.buf, &iter->base.st) < 0) {
+ if (iter->flags & DIR_ITERATOR_FOLLOW_SYMLINKS)
+ err = stat(iter->base.path.buf, &iter->base.st);
+ else
+ err = lstat(iter->base.path.buf, &iter->base.st);
+
+ if (err < 0) {
saved_errno = errno;
goto error_out;
}
diff --git a/dir-iterator.h b/dir-iterator.h
index 0822915..e3b6ff2 100644
--- a/dir-iterator.h
+++ b/dir-iterator.h
@@ -61,6 +61,11 @@
* not the symlinks themselves, which is the default behavior. Broken
* symlinks are ignored.
*
+ * Note: setting DIR_ITERATOR_FOLLOW_SYMLINKS affects resolving the
+ * starting path as well (e.g., attempting to iterate starting at a
+ * symbolic link pointing to a directory without FOLLOW_SYMLINKS will
+ * result in an error).
+ *
* Warning: circular symlinks are also followed when
* DIR_ITERATOR_FOLLOW_SYMLINKS is set. The iteration may end up with
* an ELOOP if they happen and DIR_ITERATOR_PEDANTIC is set.
diff --git a/t/t0066-dir-iterator.sh b/t/t0066-dir-iterator.sh
index 92910e4..c826f60 100755
--- a/t/t0066-dir-iterator.sh
+++ b/t/t0066-dir-iterator.sh
@@ -109,7 +109,9 @@
mkdir -p dir5/a/c &&
ln -s ../c dir5/a/b/d &&
ln -s ../ dir5/a/b/e &&
- ln -s ../../ dir5/a/b/f
+ ln -s ../../ dir5/a/b/f &&
+
+ ln -s dir4 dir6
'
test_expect_success SYMLINKS 'dir-iterator should not follow symlinks by default' '
@@ -145,4 +147,27 @@
test_cmp expected-follow-sorted-output actual-follow-sorted-output
'
+test_expect_success SYMLINKS 'dir-iterator does not resolve top-level symlinks' '
+ test_must_fail test-tool dir-iterator ./dir6 >out &&
+
+ grep "ENOTDIR" out
+'
+
+test_expect_success SYMLINKS 'dir-iterator resolves top-level symlinks w/ follow flag' '
+ cat >expected-follow-sorted-output <<-EOF &&
+ [d] (a) [a] ./dir6/a
+ [d] (a/f) [f] ./dir6/a/f
+ [d] (a/f/c) [c] ./dir6/a/f/c
+ [d] (b) [b] ./dir6/b
+ [d] (b/c) [c] ./dir6/b/c
+ [f] (a/d) [d] ./dir6/a/d
+ [f] (a/e) [e] ./dir6/a/e
+ EOF
+
+ test-tool dir-iterator --follow-symlinks ./dir6 >out &&
+ sort out >actual-follow-sorted-output &&
+
+ test_cmp expected-follow-sorted-output actual-follow-sorted-output
+'
+
test_done
diff --git a/t/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh
index 872fcda..1acb7b2 100755
--- a/t/t4115-apply-symlink.sh
+++ b/t/t4115-apply-symlink.sh
@@ -44,4 +44,85 @@
'
+test_expect_success 'symlink setup' '
+ ln -s .git symlink &&
+ git add symlink &&
+ git commit -m "add symlink"
+'
+
+test_expect_success SYMLINKS 'symlink escape when creating new files' '
+ test_when_finished "git reset --hard && git clean -dfx" &&
+
+ cat >patch <<-EOF &&
+ diff --git a/symlink b/renamed-symlink
+ similarity index 100%
+ rename from symlink
+ rename to renamed-symlink
+ --
+ diff --git /dev/null b/renamed-symlink/create-me
+ new file mode 100644
+ index 0000000..039727e
+ --- /dev/null
+ +++ b/renamed-symlink/create-me
+ @@ -0,0 +1,1 @@
+ +busted
+ EOF
+
+ test_must_fail git apply patch 2>stderr &&
+ cat >expected_stderr <<-EOF &&
+ error: affected file ${SQ}renamed-symlink/create-me${SQ} is beyond a symbolic link
+ EOF
+ test_cmp expected_stderr stderr &&
+ ! test_path_exists .git/create-me
+'
+
+test_expect_success SYMLINKS 'symlink escape when modifying file' '
+ test_when_finished "git reset --hard && git clean -dfx" &&
+ touch .git/modify-me &&
+
+ cat >patch <<-EOF &&
+ diff --git a/symlink b/renamed-symlink
+ similarity index 100%
+ rename from symlink
+ rename to renamed-symlink
+ --
+ diff --git a/renamed-symlink/modify-me b/renamed-symlink/modify-me
+ index 1111111..2222222 100644
+ --- a/renamed-symlink/modify-me
+ +++ b/renamed-symlink/modify-me
+ @@ -0,0 +1,1 @@
+ +busted
+ EOF
+
+ test_must_fail git apply patch 2>stderr &&
+ cat >expected_stderr <<-EOF &&
+ error: renamed-symlink/modify-me: No such file or directory
+ EOF
+ test_cmp expected_stderr stderr &&
+ test_must_be_empty .git/modify-me
+'
+
+test_expect_success SYMLINKS 'symlink escape when deleting file' '
+ test_when_finished "git reset --hard && git clean -dfx && rm .git/delete-me" &&
+ touch .git/delete-me &&
+
+ cat >patch <<-EOF &&
+ diff --git a/symlink b/renamed-symlink
+ similarity index 100%
+ rename from symlink
+ rename to renamed-symlink
+ --
+ diff --git a/renamed-symlink/delete-me b/renamed-symlink/delete-me
+ deleted file mode 100644
+ index 1111111..0000000 100644
+ EOF
+
+ test_must_fail git apply patch 2>stderr &&
+ cat >expected_stderr <<-EOF &&
+ error: renamed-symlink/delete-me: No such file or directory
+ EOF
+ test_cmp expected_stderr stderr &&
+ test_path_is_file .git/delete-me
+'
+
test_done
diff --git a/t/t5604-clone-reference.sh b/t/t5604-clone-reference.sh
index 6fb7a6e..574d8c4 100755
--- a/t/t5604-clone-reference.sh
+++ b/t/t5604-clone-reference.sh
@@ -344,4 +344,20 @@
test_must_be_empty T--shared.objects-symlinks.raw
'
+test_expect_success SYMLINKS 'clone repo with symlinked objects directory' '
+ test_when_finished "rm -fr sensitive malicious" &&
+
+ mkdir -p sensitive &&
+ echo "secret" >sensitive/file &&
+
+ git init malicious &&
+ rm -fr malicious/.git/objects &&
+ ln -s "$(pwd)/sensitive" ./malicious/.git/objects &&
+
+ test_must_fail git clone --local malicious clone 2>err &&
+
+ test_path_is_missing clone &&
+ grep "failed to start iterator over" err
+'
+
test_done
diff --git a/t/t5619-clone-local-ambiguous-transport.sh b/t/t5619-clone-local-ambiguous-transport.sh
new file mode 100755
index 0000000..cce62bf
--- /dev/null
+++ b/t/t5619-clone-local-ambiguous-transport.sh
@@ -0,0 +1,70 @@
+#!/bin/sh
+
+test_description='test local clone with ambiguous transport'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-httpd.sh"
+
+if ! test_have_prereq SYMLINKS
+then
+ skip_all='skipping test, symlink support unavailable'
+ test_done
+fi
+
+start_httpd
+
+REPO="$HTTPD_DOCUMENT_ROOT_PATH/sub.git"
+URI="$HTTPD_URL/dumb/sub.git"
+
+test_expect_success 'setup' '
+ mkdir -p sensitive &&
+ echo "secret" >sensitive/secret &&
+
+ git init --bare "$REPO" &&
+ test_commit_bulk -C "$REPO" --ref=main 1 &&
+
+ git -C "$REPO" update-ref HEAD main &&
+ git -C "$REPO" update-server-info &&
+
+ git init malicious &&
+ (
+ cd malicious &&
+
+ git submodule add "$URI" &&
+
+ mkdir -p repo/refs &&
+ touch repo/refs/.gitkeep &&
+ printf "ref: refs/heads/a" >repo/HEAD &&
+ ln -s "$(cd .. && pwd)/sensitive" repo/objects &&
+
+ mkdir -p "$HTTPD_URL/dumb" &&
+ ln -s "../../../.git/modules/sub/../../../repo/" "$URI" &&
+
+ git add . &&
+ git commit -m "initial commit"
+ ) &&
+
+ # Delete all of the references in our malicious submodule to
+ # avoid the client attempting to checkout any objects (which
+ # will be missing, and thus will cause the clone to fail before
+ # we can trigger the exploit).
+ git -C "$REPO" for-each-ref --format="delete %(refname)" >in &&
+ git -C "$REPO" update-ref --stdin <in &&
+ git -C "$REPO" update-server-info
+'
+
+test_expect_success 'ambiguous transport does not lead to arbitrary file-inclusion' '
+ git clone malicious clone &&
+ test_must_fail git -C clone submodule update --init 2>err &&
+
+ test_path_is_missing clone/.git/modules/sub/objects/secret &&
+ # We would actually expect "transport .file. not allowed" here,
+ # but due to quirks of the URL detection in Git, we mis-parse
+ # the absolute path as a bogus URL and die before that step.
+ #
+ # This works for now, and if we ever fix the URL detection, it
+ # is OK to change this to detect the transport error.
+ grep "protocol .* is not supported" err
+'
+
+test_done
