Make sure file capabilities are not lost over copy-up when file is opened for WRITE but nothing is actually written to it. Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> --- tests/overlay/064 | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/overlay/064.out | 2 + tests/overlay/group | 1 3 files changed, 74 insertions(+) Index: xfstests-dev/tests/overlay/064 =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ xfstests-dev/tests/overlay/064 2019-01-11 13:18:16.900461223 -0500 @@ -0,0 +1,71 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2018 Red Hat Inc. All Rights Reserved. +# +# FS QA Test 064 +# +# Make sure CAP_SETUID is not cleared over file copy up. +# +# Following commit introduced regression where if a lower file with +# CAP_SETUID is opened for writing, and capability is cleared over copy up. +# +# bd64e57586d3 ("ovl: During copy up, first copy up metadata and then data") +# +# A later kernel patch will fix it. This test will help avoid introducing +# such regressions again. +# +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +tmp=/tmp/$$ +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + cd / + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here +_supported_fs overlay +_supported_os Linux +_require_scratch +_require_command "$SETCAP_PROG" setcap +_require_command "$GETCAP_PROG" getcap + +# Remove all files from previous tests +_scratch_mkfs + +# Create test file +lowerdir=${OVL_BASE_SCRATCH_MNT}/${OVL_LOWER} +echo "This is lower" >> ${lowerdir}/file + +# set setuid bit +$SETCAP_PROG cap_setuid+ep ${lowerdir}/file + +_scratch_mount + +# Trigger file copy up without actually writing anything to file. This +# requires opening file with WRITE and xfs_io seems to open it with +# O_RDWR by default. +$XFS_IO_PROG -c "quit" ${SCRATCH_MNT}/file >>$seqres.full + +# Make sure cap_setuid is still there +$GETCAP_PROG ${SCRATCH_MNT}/file | _filter_scratch + +# unmount overlayfs +$UMOUNT_PROG $SCRATCH_MNT + +# success, all done +status=0 +exit Index: xfstests-dev/tests/overlay/064.out =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ xfstests-dev/tests/overlay/064.out 2019-01-11 13:18:22.652461223 -0500 @@ -0,0 +1,2 @@ +QA output created by 064 +SCRATCH_MNT/file = cap_setuid+ep Index: xfstests-dev/tests/overlay/group =================================================================== --- xfstests-dev.orig/tests/overlay/group 2018-12-19 11:47:04.443031019 -0500 +++ xfstests-dev/tests/overlay/group 2019-01-10 15:43:28.053079686 -0500 @@ -66,3 +66,4 @@ 061 auto quick copyup 062 auto quick exportfs 063 auto quick whiteout +064 auto quick copyup