Re: [PATCH 10/12] ima: Move validation of the keyrings conditional into ima_validate_rule()

From: Tyler Hicks
Date: Thu Jun 25 2020 - 15:50:41 EST


On 2020-06-22 19:32:34, Tyler Hicks wrote:
> Use ima_validate_rule() to ensure that the combination of a hook
> function and the keyrings conditional is valid and that the keyrings
> conditional is not specified without an explicit KEY_CHECK func
> conditional. This is a code cleanup and has no user-facing change.
>
> Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
> ---
> security/integrity/ima/ima_policy.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 514baf24d6a5..ae2ec2a9cdb9 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -999,6 +999,12 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
> case KEXEC_KERNEL_CHECK:
> case KEXEC_INITRAMFS_CHECK:
> case POLICY_CHECK:
> + if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
> + IMA_UID | IMA_FOWNER | IMA_FSUUID |
> + IMA_INMASK | IMA_EUID | IMA_PCR |
> + IMA_FSNAME))

I accidentally left these out:

(IMA_DIGSIG_REQUIRED | IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED | IMA_CHECK_BLACKLIST)

I'll add them in v2.

Tyler

> + return false;
> +
> break;
> case KEXEC_CMDLINE:
> if (entry->action & ~(MEASURE | DONT_MEASURE))
> @@ -1026,7 +1032,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
> default:
> return false;
> }
> - }
> + } else if (entry->flags & IMA_KEYRINGS)
> + return false;
>
> return true;
> }
> @@ -1208,7 +1215,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
> keyrings_len = strlen(args[0].from) + 1;
>
> if ((entry->keyrings) ||
> - (entry->func != KEY_CHECK) ||
> (keyrings_len < 2)) {
> result = -EINVAL;
> break;
> --
> 2.25.1