Messages in this thread | | | Subject | Re: [PATCH v2 11/11] ima: Support additional conditionals in the KEXEC_CMDLINE hook function | From | Lakshmi Ramasubramanian <> | Date | Sat, 27 Jun 2020 17:03:11 -0700 |
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On 6/26/20 3:39 PM, Tyler Hicks wrote: > Take the properties of the kexec kernel's inode and the current task > ownership into consideration when matching a KEXEC_CMDLINE operation to > the rules in the IMA policy. This allows for some uniformity when > writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK, > and KEXEC_CMDLINE operations. > > Prior to this patch, it was not possible to write a set of rules like > this: > > dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t > dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t > dont_measure func=KEXEC_CMDLINE obj_type=foo_t > measure func=KEXEC_KERNEL_CHECK > measure func=KEXEC_INITRAMFS_CHECK > measure func=KEXEC_CMDLINE > > The inode information associated with the kernel being loaded by a > kexec_kernel_load(2) syscall can now be included in the decision to > measure or not > > Additonally, the uid, euid, and subj_* conditionals can also now be > used in KEXEC_CMDLINE rules. There was no technical reason as to why > those conditionals weren't being considered previously other than > ima_match_rules() didn't have a valid inode to use so it immediately > bailed out for KEXEC_CMDLINE operations rather than going through the > full list of conditional comparisons. > > Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> > Cc: Eric Biederman <ebiederm@xmission.com> > Cc: kexec@lists.infradead.org > --- > > * v2 > - Moved the inode parameter of process_buffer_measurement() to be the > first parameter so that it more closely matches process_masurement() > > include/linux/ima.h | 4 ++-- > kernel/kexec_file.c | 2 +- > security/integrity/ima/ima.h | 2 +- > security/integrity/ima/ima_api.c | 2 +- > security/integrity/ima/ima_appraise.c | 2 +- > security/integrity/ima/ima_asymmetric_keys.c | 2 +- > security/integrity/ima/ima_main.c | 23 +++++++++++++++----- > security/integrity/ima/ima_policy.c | 17 +++++---------- > security/integrity/ima/ima_queue_keys.c | 2 +- > 9 files changed, 31 insertions(+), 25 deletions(-) >
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
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