| Message ID | 20200727223041.13110-5-pvorel@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IMA: kexec cmdline measurement | expand |
Hi Petr, This patch removes the test of the `--reuse-cmdline` option of kexec. Go ahead and merge this, and then I'll post a patch that adds `--reuse-cmdline` back. Thank you, Lachlan On 7/27/20 6:30 PM, Petr Vorel wrote: > From: Lachlan Sneff <t-josne@linux.microsoft.com> > > IMA policy can be set to measure the command line passed in the kexec > system call. Add a testcase that verifies that the IMA subsystem > correctly measure the cmdline specified during a kexec. > > Reviewed-by: Petr Vorel <pvorel@suse.cz> > Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> > Signed-off-by: Lachlan Sneff <t-josne@linux.microsoft.com> > [ pvorel: improved setup, various LTP API cleanup ] > Signed-off-by: Petr Vorel <pvorel@suse.cz> > --- > Changes v4->v5: > > * added kexec.policy, please check it (for lazy people, I still plan > some automatic mechanism for loading policies on CONFIG_IMA_WRITE_POLICY) > > * rewritten checks in setup: > - simplify secure boot bootctl verification > - try dmesg when bootctl not available > - check on failure also ^appraise.*func=KEXEC_KERNEL_CHECK policy > - improve logic for func=KEXEC_CMDLINE check (instead of requiring > policy to be readable check only when readable, otherwise TWARN, ...) > - TWARN on failures in setup => TWARN is kind of error as it exit with > non-zero, but these cases are failures thus don't hide them) > > * added cleanup commit (adding helpers) > > * various LTP API cleanup: > - added setup into separate function > - reuse test code with kexec_test() > > Kind regards, > Petr > > runtest/ima | 1 + > .../kernel/security/integrity/ima/README.md | 8 ++ > .../integrity/ima/datafiles/kexec.policy | 1 + > .../security/integrity/ima/tests/ima_kexec.sh | 111 ++++++++++++++++++ > 4 files changed, 121 insertions(+) > create mode 100644 testcases/kernel/security/integrity/ima/datafiles/kexec.policy > create mode 100755 testcases/kernel/security/integrity/ima/tests/ima_kexec.sh > > diff --git a/runtest/ima b/runtest/ima > index 309d47420..5f4b4a7a1 100644 > --- a/runtest/ima > +++ b/runtest/ima > @@ -4,4 +4,5 @@ ima_policy ima_policy.sh > ima_tpm ima_tpm.sh > ima_violations ima_violations.sh > ima_keys ima_keys.sh > +ima_kexec ima_kexec.sh > evm_overlay evm_overlay.sh > diff --git a/testcases/kernel/security/integrity/ima/README.md b/testcases/kernel/security/integrity/ima/README.md > index 732cd912f..d4644ba39 100644 > --- a/testcases/kernel/security/integrity/ima/README.md > +++ b/testcases/kernel/security/integrity/ima/README.md > @@ -36,6 +36,14 @@ CONFIG_SYSTEM_TRUSTED_KEYS="/etc/keys/ima-local-ca.pem" > > Test also requires loaded policy with `func=KEY_CHECK`, see example in `keycheck.policy`. > > +### IMA kexec test > + > +`ima_kexec.sh` requires loaded policy which contains `measure func=KEXEC_CMDLINE`, > +see example in `kexec.policy`. > + > +The test attempts to kexec the existing running kernel image. > +To kexec a different kernel image export `IMA_KEXEC_IMAGE=<pathname>`. > + > ## EVM tests > > `evm_overlay.sh` requires a builtin IMA appraise tcb policy (e.g. `ima_policy=appraise_tcb` > diff --git a/testcases/kernel/security/integrity/ima/datafiles/kexec.policy b/testcases/kernel/security/integrity/ima/datafiles/kexec.policy > new file mode 100644 > index 000000000..58d66369e > --- /dev/null > +++ b/testcases/kernel/security/integrity/ima/datafiles/kexec.policy > @@ -0,0 +1 @@ > +measure func=KEXEC_CMDLINE > diff --git a/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh b/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh > new file mode 100755 > index 000000000..fbad9b425 > --- /dev/null > +++ b/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh > @@ -0,0 +1,111 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0-or-later > +# Copyright (c) 2020 Microsoft Corporation > +# Copyright (c) 2020 Petr Vorel <pvorel@suse.cz> > +# Author: Lachlan Sneff <t-josne@linux.microsoft.com> > +# > +# Verify that kexec cmdline is measured correctly. > +# Test attempts to kexec the existing running kernel image. > +# To kexec a different kernel image export IMA_KEXEC_IMAGE=<pathname>. > + > +TST_NEEDS_CMDS="grep kexec sed" > +TST_CNT=2 > +TST_NEEDS_DEVICE=1 > +TST_SETUP="setup" > + > +. ima_setup.sh > + > +IMA_KEXEC_IMAGE="${IMA_KEXEC_IMAGE:-/boot/vmlinuz-$(uname -r)}" > + > +measure() > +{ > + local cmdline="$1" > + local algorithm digest expected_digest found > + > + printf "$cmdline" > file1 > + grep "kexec-cmdline" $ASCII_MEASUREMENTS > file2 > + > + while read found > + do > + algorithm=$(echo "$found" | cut -d' ' -f4 | cut -d':' -f1) > + digest=$(echo "$found" | cut -d' ' -f4 | cut -d':' -f2) > + > + expected_digest=$(compute_digest $algorithm file1) > + > + if [ "$digest" = "$expected_digest" ]; then > + return 0 > + fi > + done < file2 > + > + return 1 > +} > + > +setup() > +{ > + local cmdline="$(sed 's/BOOT_IMAGE=[^ ]* //' /proc/cmdline)" > + local res=TBROK > + local sb_enabled > + > + if [ ! -f "$IMA_KEXEC_IMAGE" ]; then > + tst_brk TCONF "kernel image not found, specify path in \$IMA_KEXEC_IMAGE" > + fi > + > + if check_policy_readable; then > + require_ima_policy_content '^measure.*func=KEXEC_CMDLINE' > + res=TFAIL > + fi > + > + tst_res TINFO "loading kernel $IMA_KEXEC_IMAGE, cmdline: $cmdline" > + if kexec -s -l $IMA_KEXEC_IMAGE --reuse-cmdline 2>err; then > + ROD kexec -su > + if ! measure "$cmdline"; then > + if [ "$res" = TBROK ]; then > + tst_res TWARN "policy not readable, it might not contain required measure func=KEXEC_CMDLINE" > + fi > + tst_brk $res "unable to find a correct entry for --reuse-cmdline" > + fi > + return > + fi > + > + if tst_cmd_available bootctl; then > + if bootctl status 2>/dev/null | grep -qi 'Secure Boot: enabled'; then > + sb_enabled=1 > + fi > + elif tst_cmd_available dmesg; then > + if dmesg | grep -qi 'Secure boot enabled'; then > + sb_enabled=1 > + fi > + fi > + if [ "$sb_enabled" ]; then > + tst_res TWARN "secure boot is enabled, kernel image may not be signed" > + fi > + > + if check_ima_policy_content '^appraise.*func=KEXEC_KERNEL_CHECK'; then > + tst_res TWARN "'func=KEXEC_KERNEL_CHECK' appraise policy loaded, kernel image may not be signed" > + fi > + > + tst_brk TBROK "kexec failed: $(cat err)" > +} > + > +kexec_test() > +{ > + local cmdline="$1" > + local param="$2" > + > + EXPECT_PASS_BRK kexec -s -l $IMA_KEXEC_IMAGE $param=$cmdline > + ROD kexec -su > + if ! measure "$cmdline"; then > + tst_brk TFAIL "unable to find a correct entry for $param=$cmdline" > + fi > + tst_res TPASS "kexec cmdline for $param=$cmdline was measured correctly" > +} > + > +test() > +{ > + case $1 in > + 1) kexec_test 'foo' '--append';; > + 2) kexec_test 'bar' '--command-line';; > + esac > +} > + > +tst_run
Hi Lachlan, > This patch removes the test of the `--reuse-cmdline` option of kexec. > Go ahead and merge this, and then I'll post a patch that adds > `--reuse-cmdline` back. Thanks for the report, I'll send v6. Kind regards, Petr
diff --git a/runtest/ima b/runtest/ima index 309d47420..5f4b4a7a1 100644 --- a/runtest/ima +++ b/runtest/ima @@ -4,4 +4,5 @@ ima_policy ima_policy.sh ima_tpm ima_tpm.sh ima_violations ima_violations.sh ima_keys ima_keys.sh +ima_kexec ima_kexec.sh evm_overlay evm_overlay.sh diff --git a/testcases/kernel/security/integrity/ima/README.md b/testcases/kernel/security/integrity/ima/README.md index 732cd912f..d4644ba39 100644 --- a/testcases/kernel/security/integrity/ima/README.md +++ b/testcases/kernel/security/integrity/ima/README.md @@ -36,6 +36,14 @@ CONFIG_SYSTEM_TRUSTED_KEYS="/etc/keys/ima-local-ca.pem" Test also requires loaded policy with `func=KEY_CHECK`, see example in `keycheck.policy`. +### IMA kexec test + +`ima_kexec.sh` requires loaded policy which contains `measure func=KEXEC_CMDLINE`, +see example in `kexec.policy`. + +The test attempts to kexec the existing running kernel image. +To kexec a different kernel image export `IMA_KEXEC_IMAGE=<pathname>`. + ## EVM tests `evm_overlay.sh` requires a builtin IMA appraise tcb policy (e.g. `ima_policy=appraise_tcb` diff --git a/testcases/kernel/security/integrity/ima/datafiles/kexec.policy b/testcases/kernel/security/integrity/ima/datafiles/kexec.policy new file mode 100644 index 000000000..58d66369e --- /dev/null +++ b/testcases/kernel/security/integrity/ima/datafiles/kexec.policy @@ -0,0 +1 @@ +measure func=KEXEC_CMDLINE diff --git a/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh b/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh new file mode 100755 index 000000000..fbad9b425 --- /dev/null +++ b/testcases/kernel/security/integrity/ima/tests/ima_kexec.sh @@ -0,0 +1,111 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2020 Microsoft Corporation +# Copyright (c) 2020 Petr Vorel <pvorel@suse.cz> +# Author: Lachlan Sneff <t-josne@linux.microsoft.com> +# +# Verify that kexec cmdline is measured correctly. +# Test attempts to kexec the existing running kernel image. +# To kexec a different kernel image export IMA_KEXEC_IMAGE=<pathname>. + +TST_NEEDS_CMDS="grep kexec sed" +TST_CNT=2 +TST_NEEDS_DEVICE=1 +TST_SETUP="setup" + +. ima_setup.sh + +IMA_KEXEC_IMAGE="${IMA_KEXEC_IMAGE:-/boot/vmlinuz-$(uname -r)}" + +measure() +{ + local cmdline="$1" + local algorithm digest expected_digest found + + printf "$cmdline" > file1 + grep "kexec-cmdline" $ASCII_MEASUREMENTS > file2 + + while read found + do + algorithm=$(echo "$found" | cut -d' ' -f4 | cut -d':' -f1) + digest=$(echo "$found" | cut -d' ' -f4 | cut -d':' -f2) + + expected_digest=$(compute_digest $algorithm file1) + + if [ "$digest" = "$expected_digest" ]; then + return 0 + fi + done < file2 + + return 1 +} + +setup() +{ + local cmdline="$(sed 's/BOOT_IMAGE=[^ ]* //' /proc/cmdline)" + local res=TBROK + local sb_enabled + + if [ ! -f "$IMA_KEXEC_IMAGE" ]; then + tst_brk TCONF "kernel image not found, specify path in \$IMA_KEXEC_IMAGE" + fi + + if check_policy_readable; then + require_ima_policy_content '^measure.*func=KEXEC_CMDLINE' + res=TFAIL + fi + + tst_res TINFO "loading kernel $IMA_KEXEC_IMAGE, cmdline: $cmdline" + if kexec -s -l $IMA_KEXEC_IMAGE --reuse-cmdline 2>err; then + ROD kexec -su + if ! measure "$cmdline"; then + if [ "$res" = TBROK ]; then + tst_res TWARN "policy not readable, it might not contain required measure func=KEXEC_CMDLINE" + fi + tst_brk $res "unable to find a correct entry for --reuse-cmdline" + fi + return + fi + + if tst_cmd_available bootctl; then + if bootctl status 2>/dev/null | grep -qi 'Secure Boot: enabled'; then + sb_enabled=1 + fi + elif tst_cmd_available dmesg; then + if dmesg | grep -qi 'Secure boot enabled'; then + sb_enabled=1 + fi + fi + if [ "$sb_enabled" ]; then + tst_res TWARN "secure boot is enabled, kernel image may not be signed" + fi + + if check_ima_policy_content '^appraise.*func=KEXEC_KERNEL_CHECK'; then + tst_res TWARN "'func=KEXEC_KERNEL_CHECK' appraise policy loaded, kernel image may not be signed" + fi + + tst_brk TBROK "kexec failed: $(cat err)" +} + +kexec_test() +{ + local cmdline="$1" + local param="$2" + + EXPECT_PASS_BRK kexec -s -l $IMA_KEXEC_IMAGE $param=$cmdline + ROD kexec -su + if ! measure "$cmdline"; then + tst_brk TFAIL "unable to find a correct entry for $param=$cmdline" + fi + tst_res TPASS "kexec cmdline for $param=$cmdline was measured correctly" +} + +test() +{ + case $1 in + 1) kexec_test 'foo' '--append';; + 2) kexec_test 'bar' '--command-line';; + esac +} + +tst_run