Re: [RFC PATCH 3/3] ima: additional ToMToU violation tests

[Petr Vorel <pvorel@suse.cz>]

Hi Mimi,

> Hi Mimi,

> > Kernel patch "ima: limit the number of ToMToU integrity violations"
> > prevents superfluous ToMToU violations.  Add corresponding LTP tests.

> > Link: https://lore.kernel.org/linux-integrity/20250219162131.416719-3-zohar@linux.ibm.com/
> > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

> Unfortunately tests fail on both mainline kernel and kernel with your patches.

> Any hint what could be wrong?

> Mainline kernel (on kernel with your patches it looks the same):

I'm sorry, I accidentally tested only on vanilla kernel. Rerunning tests with
updated kernel.

Is it this considered as a security feature? If yes, than failures on vanilla
kernel are ok, we just need to later add kernel hashes to let testers know about
missing backports. If it's a feature (not to be backported) we should test new
feature only on newer kernels.

Kind regards,
Petr

> ima_violations 1 TINFO: Running: ima_violations.sh
> ima_violations 1 TINFO: Tested kernel: Linux ts 6.13.0-2.g0127a37-default #1 SMP PREEMPT_DYNAMIC Thu Jan 23 11:21:55 UTC 2025 (0127a37) x86_64 x86_64 x86_64 GNU/Linux
> ima_violations 1 TINFO: Using /tmp/LTP_ima_violations.cKm34XVZk2 as tmpdir (tmpfs filesystem)
> tst_device.c:99: TINFO: Found free device 0 '/dev/loop0'
> ima_violations 1 TINFO: Formatting ext3 with opts='/dev/loop0'
> ima_violations 1 TINFO: Mounting device: mount -t ext3 /dev/loop0 /tmp/LTP_ima_violations.cKm34XVZk2/mntpoint
> ima_violations 1 TINFO: timeout per run is 0h 5m 0s
> ima_violations 1 TINFO: IMA kernel config:
> ima_violations 1 TINFO: CONFIG_IMA=y
> ima_violations 1 TINFO: CONFIG_IMA_MEASURE_PCR_IDX=10
> ima_violations 1 TINFO: CONFIG_IMA_LSM_RULES=y
> ima_violations 1 TINFO: CONFIG_IMA_NG_TEMPLATE=y
> ima_violations 1 TINFO: CONFIG_IMA_DEFAULT_TEMPLATE="ima-ng"
> ima_violations 1 TINFO: CONFIG_IMA_DEFAULT_HASH_SHA256=y
> ima_violations 1 TINFO: CONFIG_IMA_DEFAULT_HASH="sha256"
> ima_violations 1 TINFO: CONFIG_IMA_READ_POLICY=y
> ima_violations 1 TINFO: CONFIG_IMA_APPRAISE=y
> ima_violations 1 TINFO: CONFIG_IMA_ARCH_POLICY=y
> ima_violations 1 TINFO: CONFIG_IMA_APPRAISE_BOOTPARAM=y
> ima_violations 1 TINFO: CONFIG_IMA_APPRAISE_MODSIG=y
> ima_violations 1 TINFO: CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS=y
> ima_violations 1 TINFO: CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS=y
> ima_violations 1 TINFO: CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT=y
> ima_violations 1 TINFO: CONFIG_IMA_DISABLE_HTABLE=y
> ima_violations 1 TINFO: /proc/cmdline: BOOT_IMAGE=/boot/vmlinuz-6.13.0-2.g0127a37-default root=UUID=e36b2366-1af2-4408-903c-1fca82c60f4c splash=silent video=1024x768 plymouth.ignore-serial-consoles console=ttyS0 console=tty kernel.softlockup_panic=1 resume=/dev/disk/by-uuid/c3b865f9-5d5b-410e-a6d1-9ebcf721584c mitigations=auto security=apparmor ignore_loglevel
> ima_violations 1 TINFO: $TMPDIR is on tmpfs => run on loop device
> ima_violations 1 TINFO: test requires IMA policy:
> measure func=FILE_CHECK mask=^MAY_READ euid=0
> measure func=FILE_CHECK mask=^MAY_READ uid=0
> ima_violations 1 TINFO: SUT has required policy content
> ima_violations 1 TINFO: using log /var/log/audit/audit.log
> ima_violations 1 TINFO: verify open writers violation
> ima_violations 1 TFAIL: open_writers too many violations added
> ima_violations 2 TINFO: verify ToMToU violation
> ima_violations 2 TFAIL: ToMToU too many violations added
> ima_violations 3 TINFO: verify open_writers using mmapped files
> tst_test.c:1900: TINFO: LTP version: 20250130-22-gcd2215702f
> tst_test.c:1904: TINFO: Tested kernel: 6.13.0-2.g0127a37-default #1 SMP PREEMPT_DYNAMIC Thu Jan 23 11:21:55 UTC 2025 (0127a37) x86_64
> tst_kconfig.c:88: TINFO: Parsing kernel config '/proc/config.gz'
> tst_kconfig.c:676: TINFO: CONFIG_FAULT_INJECTION kernel option detected which might slow the execution
> tst_test.c:1722: TINFO: Overall timeout per run is 0h 02m 00s
> ima_mmap.c:38: TINFO: sleep 3s
> ima_violations 3 TFAIL: open_writers too many violations added
> ima_mmap.c:41: TPASS: test completed

> Summary:
> passed   1
> failed   0
> broken   0
> skipped  0
> warnings 0
> ima_violations 4 TINFO: verify limiting single open writer violation
> ima_violations 4 TFAIL: open_writers too many violations added
> ima_violations 5 TINFO: verify limiting multiple open writers violations
> ima_violations 5 TFAIL: open_writers too many violations added
> ima_violations 6 TINFO: verify new open writer causes additional violation
> ima_violations 6 TFAIL: open_writers too many violations added
> ima_violations 7 TINFO: verify limiting single open reader ToMToU violations
> ima_violations 7 TFAIL: ToMToU too many violations added
> ima_violations 8 TINFO: verify new open reader causes additional ToMToU violation
> ima_violations 8 TFAIL: ToMToU too many violations added

> Kind regards,
> Petr