test demonstrate a bug on overlayfs on current mainline kernel when combining IMA with EVM. Based on reproducer made by Ignaz Forster <iforster@xxxxxxx> used for not upstreamed patchset [1] and previous report [2]. IMA only behavior has already been fixed [3]. NOTE: backup variables are needed because ima_setup.sh calling tst_mount as well when TMPDIR is on tmpfs device. [1] https://www.spinics.net/lists/linux-integrity/msg05926.html [2] https://www.spinics.net/lists/linux-integrity/msg03593.html [3] https://patchwork.kernel.org/patch/10776231/ Tested-by: Ignaz Forster <iforster@xxxxxxx> Signed-off-by: Petr Vorel <pvorel@xxxxxxx> --- Changes v1->v2: * Added 2 more tests (suggested by Ignaz): append file and create a new file. Tests has been further split to 4 tests (previously was only 1). * Fixed testing on tmpfs (reported by Mimi) by adding TST_NEEDS_DEVICE=1. * Renamed file to evm_overlay.sh (from ima_overlay.sh; suggested by Ignaz). Obviously it's about IMA + EVM, but IMHO 'ima' can be left from filename. * Changed pattern for kernel parameters check (suggested by Mimi). TODO/questions: Still not sure what is a proper setup. Should I check EVM enabled? /sys/kernel/security/evm should be 1? I suppose different behaviour between ima_policy=appraise_tcb and ima_appraise_tcb is just my wrong setup. Thanks a lot for your comments. Kind regards, Petr --- runtest/ima | 1 + .../integrity/ima/tests/evm_overlay.sh | 86 +++++++++++++++++++ .../security/integrity/ima/tests/ima_setup.sh | 4 +- 3 files changed, 89 insertions(+), 2 deletions(-) create mode 100755 testcases/kernel/security/integrity/ima/tests/evm_overlay.sh diff --git a/runtest/ima b/runtest/ima index bcae16bb7..f3ea88cf0 100644 --- a/runtest/ima +++ b/runtest/ima @@ -3,3 +3,4 @@ ima_measurements ima_measurements.sh ima_policy ima_policy.sh ima_tpm ima_tpm.sh ima_violations ima_violations.sh +evm_overlay evm_overlay.sh diff --git a/testcases/kernel/security/integrity/ima/tests/evm_overlay.sh b/testcases/kernel/security/integrity/ima/tests/evm_overlay.sh new file mode 100755 index 000000000..08ec1ea37 --- /dev/null +++ b/testcases/kernel/security/integrity/ima/tests/evm_overlay.sh @@ -0,0 +1,86 @@ +#!/bin/sh +# Copyright (c) 2019 Petr Vorel <pvorel@xxxxxxx> +# Based on reproducer and further discussion with Ignaz Forster <iforster@xxxxxxx> + +TST_SETUP="setup" +TST_CLEANUP="cleanup" +TST_NEEDS_DEVICE=1 +TST_CNT=4 +. ima_setup.sh + +setup() +{ + lower="$TST_MNTPOINT/lower" + upper="$TST_MNTPOINT/upper" + work="$TST_MNTPOINT/work" + merged="$TST_MNTPOINT/merged" + mkdir -p $lower $upper $work $merged + + device_backup="$TST_DEVICE" + TST_DEVICE="overlay" + + fs_type_backup="$TST_FS_TYPE" + TST_FS_TYPE="overlay" + + mntpoint_backup="$TST_MNTPOINT" + TST_MNTPOINT="$merged" + + params_backup="$TST_MNT_PARAMS" + TST_MNT_PARAMS="-o lowerdir=$lower,upperdir=$upper,workdir=$work" + + grep -q -e ima_policy= -e ima_appraise_tcb /proc/cmdline || \ + tst_brk TCONF "Test requires specify IMA policy as kernel parameter" + + tst_mount + mounted=1 +} + +test1() +{ + local file="foo1.txt" + + tst_res TINFO "overwrite file in overlay" + ROD echo lower \> $lower/$file + EXPECT_PASS echo overlay \> $merged/$file +} + +test2() +{ + local file="foo2.txt" + + tst_res TINFO "append file in overlay" + ROD echo lower \> $lower/$file + EXPECT_PASS echo overlay \>\> $merged/$file +} + +test3() +{ + local file="foo3.txt" + + tst_res TINFO "create a new file in overlay" + EXPECT_PASS echo overlay \> $merged/$file +} + +test4() +{ + local f + + tst_res TINFO "read all created files" + for f in $(find $TST_MNTPOINT -type f); do + EXPECT_PASS cat $f \> /dev/null 2\> /dev/null + done +} + +cleanup() +{ + [ -n "$mounted" ] || return 0 + + tst_umount $TST_DEVICE + + TST_DEVICE="$device_backup" + TST_FS_TYPE="$fs_type_backup" + TST_MNTPOINT="$mntpoint_backup" + TST_MNT_PARAMS="$params_backup" +} + +tst_run diff --git a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh index da49eb1b2..08aa5300a 100644 --- a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh +++ b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh @@ -64,14 +64,14 @@ print_ima_config() local config="/boot/config-$(uname -r)" local i - tst_res TINFO "/proc/cmdline: $(cat /proc/cmdline)" - if [ -r "$config" ]; then tst_res TINFO "IMA kernel config:" for i in $(grep ^CONFIG_IMA $config); do tst_res TINFO "$i" done fi + + tst_res TINFO "/proc/cmdline: $(cat /proc/cmdline)" } ima_setup() -- 2.21.0
