From: Christian Brauner <brauner@xxxxxxxxxx>
When group ownership is changed a caller whose fsuid owns the inode
can change the group of the inode to any group they are a member of.
When searching through the caller's groups we failed to use the gid
mapped according to the idmapped mount otherwise we fail to change
ownership. Add a test for this.
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
---
tests/generic/698 | 117 ++++++++++++++++++++++++++++++++++++++++++
tests/generic/698.out | 19 +++++++
2 files changed, 136 insertions(+)
create mode 100755 tests/generic/698
create mode 100644 tests/generic/698.out
diff --git a/tests/generic/698 b/tests/generic/698
new file mode 100755
index 00000000..143490b2
--- /dev/null
+++ b/tests/generic/698
@@ -0,0 +1,117 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022 Christian Brauner (Microsoft). All Rights Reserved.
+#
+# FS QA Test 698
+#
+# Test that users can changed group ownership of a file they own to a group
+# they are a member of.
+#
+# Regression test for commit:
+# 168f91289340 ("fs: account for group membership")
+#
+. ./common/preamble
+_begin_fstest auto quick perms attr idmapped mount
+
+# Override the default cleanup function.
+_cleanup()
+{
+ cd /
+ $UMOUNT_PROG $SCRATCH_MNT/target-mnt 2>/dev/null
+ $UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
+ rm -r -f $tmp.*
+}
+
+# real QA test starts here
+_supported_fs generic
+_fixed_by_kernel_commit 168f91289340 \
+ "fs: account for group membership"
+_require_scratch
+_require_chown
+_require_idmapped_mounts
+_require_test_program "vfs/mount-idmapped"
+_require_user fsgqa2
+_require_group fsgqa2
+# Do this SECOND so that qa_user is fsgqa, and _user_do uses that account
+_require_user fsgqa
+_require_group fsgqa
+
+user_foo=`id -u fsgqa`
+group_foo=`id -g fsgqa`
+user_bar=`id -u fsgqa2`
+group_bar=`id -g fsgqa2`
+
+setup_tree()
+{
+ mkdir -p $SCRATCH_MNT/source-mnt
+ chmod 0777 $SCRATCH_MNT/source-mnt
+ touch $SCRATCH_MNT/source-mnt/file1
+ chown 65534:65534 $SCRATCH_MNT
+ chown 65534:65534 $SCRATCH_MNT/source-mnt
+ chown 65534:65535 $SCRATCH_MNT/source-mnt/file1
+
+ mkdir -p $SCRATCH_MNT/target-mnt
+ chmod 0777 $SCRATCH_MNT/target-mnt
+}
+
+# Setup an idmapped mount where uid and gid 65534 are mapped to fsgqa and uid
+# and gid 65535 are mapped to fsgqa2.
+setup_idmapped_mnt()
+{
+ $here/src/vfs/mount-idmapped \
+ --map-mount=u:65534:$user_foo:1 \
+ --map-mount=g:65534:$group_foo:1 \
+ --map-mount=u:65535:$user_bar:1 \
+ --map-mount=g:65535:$group_bar:1 \
+ $SCRATCH_MNT/source-mnt $SCRATCH_MNT/target-mnt
+}
+
+# We've created a layout where fsgqa owns the target file but the group of the
+# target file is owned by another group. We now test that user fsgqa can change
+# the group ownership of the file to a group they control. In this case to the
+# fsgqa group.
+change_group_ownership()
+{
+ local path="$1"
+
+ stat -c '%U:%G' $path
+ _user_do "id -u --name; id -g --name; chgrp $group_foo $path"
+ stat -c '%U:%G' $path
+ _user_do "id -u --name; id -g --name; chgrp $group_bar $path > /dev/null 2>&1"
+ stat -c '%U:%G' $path
+}
+
+run_base_test()
+{
+ mkdir -p $SCRATCH_MNT/source-mnt
+ chmod 0777 $SCRATCH_MNT/source-mnt
+ touch $SCRATCH_MNT/source-mnt/file1
+ chown $user_foo:$group_foo $SCRATCH_MNT
+ chown $user_foo:$group_foo $SCRATCH_MNT/source-mnt
+ chown $user_foo:$group_bar $SCRATCH_MNT/source-mnt/file1
+
+ echo ""
+ echo "base test"
+ change_group_ownership "$SCRATCH_MNT/source-mnt/file1"
+ rm -rf "$SCRATCH_MNT/source-mnt"
+}
+
+# Basic test as explained in the comment for change_group_ownership().
+run_idmapped_test()
+{
+ echo ""
+ echo "base idmapped test"
+ change_group_ownership "$SCRATCH_MNT/target-mnt/file1"
+}
+
+_scratch_mkfs >> $seqres.full
+_scratch_mount
+
+run_base_test
+setup_tree
+setup_idmapped_mnt
+run_idmapped_test
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/698.out b/tests/generic/698.out
new file mode 100644
index 00000000..519234b5
--- /dev/null
+++ b/tests/generic/698.out
@@ -0,0 +1,19 @@
+QA output created by 698
+
+base test
+fsgqa:fsgqa2
+fsgqa
+fsgqa
+fsgqa:fsgqa
+fsgqa
+fsgqa
+fsgqa:fsgqa
+
+base idmapped test
+fsgqa:fsgqa2
+fsgqa
+fsgqa
+fsgqa:fsgqa
+fsgqa
+fsgqa
+fsgqa:fsgqa
--
2.31.1
