Hi, everyone Now I'm testing ima-evm security module to see if it can be applied my embedded system board. (not using TPM) The kernel version is 5.4.91 (based on beaglebone black board). But, unfortunately I cannot verify the functions of ima-evm correctly. When I apply "appraise", kernel panic happens. This is what happened: (1) I set ima-evm keys as follows :     # dd if=/dev/urandom bs=1 count=32 status=none | keyctl padd user kmk-user @u     # keyctl link @u @s     #keyctl pipe `key search @u user kmk-user` > /etc/keys/kmk-user.blob     #keycl add encrypted evm-key "new user:kmk-user 32" @u     #keyctl pipe `keyctl search @u encrypted evm-key` > /etc/keys/evm-user.blob     # openssl genrsa -out /etc/keys/rsa_private.pem 1024     # openssl rsa -pubout -in /etc/keys/rsa_private.pem -out /etc/keys/rsa_public.pem (2) I set kernel parameters with *"ima_policy=appraise_tcb ima_appraise=fix evm=fix"* (3) After boot, I loaded the keys lik this:     # keyctl add user kmk-user "`cat /etc/keys/kmk-user.blob`" @u     # keyctl link @u @s     # keyctl add encrypted evm-key "load `cat /etc/keys/evm-user.blob`" @u     # evmctl import --rsa /etc/keys/rsa_public.pem $(keyctl newring _ima @u)     # evmctl import --rsa /etc/keys/rsa_public.pem $(keyctl newring _evm @u)     # echo 1 > /sys/kernel/security/evm (4) I created the ima-evm digital signatures :     # find / -type f -exec evmctl ima_sign --key /etc/keys/rsa_private.pem '{}' \; (5) I changed the kernel parameter as this : *"ima_policy=appraise_tcb ima_appraise=enforce"* (6) When the board reboot, it stop because of kernel panic : *[    3.546536] audit: type=1800 audit(946688023.636:2): pid=1 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=appraise_data cause=unknown comm="swapper" name="/lib/systemd/systemd" dev="mmcblk0p1" ino=5684 res=0* When the kernel parameter is "ima_policy=tcb ima_appraise=enforce", kernel panic does not happen, but after boot, any executable file is not blocked although its contents is changed. Please give me an advice. Thanks in advance, J.Hwan Kim