Re: [userspace PATCH v2 2/2] Check exclude filter cred extension fields available in kernel

[Steve Grubb <sgrubb@redhat.com>]

On Thursday, August 18, 2016 2:33:20 PM EDT Richard Guy Briggs wrote:
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  trunk/lib/errormsg.h |    2 +-
>  trunk/lib/libaudit.c |   39 ++++++++++++++++++++++-----------------
>  trunk/lib/libaudit.h |    3 +++
>  3 files changed, 26 insertions(+), 18 deletions(-)
> 
> diff --git a/trunk/lib/errormsg.h b/trunk/lib/errormsg.h
> index 84bfdb3..4a897be 100644
> --- a/trunk/lib/errormsg.h
> +++ b/trunk/lib/errormsg.h
> @@ -47,7 +47,7 @@ static const struct msg_tab err_msgtab[] = {
>      { -9,    0,    "msgtype field can only be used with exclude filter
> list" }, { -10,    0,    "Failed upgrading rule" },
>      { -11,    0,    "String value too long" },
> -    { -12,    0,    "Only msgtype field can be used with exclude filter" },
> +    { -12,    0,    "Only msgtype, uid, gid, auid*, subj* fields can be
> used with exclude filter" }, { -13,    1,    "only takes = or != operators"
> },
>      { -14,    0,    "Permission can only contain  \'rwxa\'" },
>      { -15,    2,    "-F unknown errno -"},
> diff --git a/trunk/lib/libaudit.c b/trunk/lib/libaudit.c
> index 798b3c8..5ffc38c 100644
> --- a/trunk/lib/libaudit.c
> +++ b/trunk/lib/libaudit.c
> @@ -1401,23 +1401,28 @@ int audit_rule_fieldpair_data(struct audit_rule_data
> **rulep, const char *pair, return -2;
> 
>  	/* Exclude filter can be used only with MSGTYPE and cred fields */
> -	if (flags == AUDIT_FILTER_EXCLUDE)
> -		switch(field) {
> -			case AUDIT_PID:
> -			case AUDIT_UID:
> -			case AUDIT_GID:
> -			case AUDIT_LOGINUID:
> -			case AUDIT_LOGINUID_SET:
> -			case AUDIT_MSGTYPE:
> -			case AUDIT_SUBJ_USER:
> -			case AUDIT_SUBJ_ROLE:
> -			case AUDIT_SUBJ_TYPE:
> -			case AUDIT_SUBJ_SEN:
> -			case AUDIT_SUBJ_CLR:
> -				break;
> -			default:
> -				return -12;
> -		}
> +	if (flags == AUDIT_FILTER_EXCLUDE) {
> +		if ((features & AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND) == 0) {

One question, why is this being and'ed directly? I was told that we have to go 
through AUDIT_FEATURE_TO_MASK() to convert the value to a mask which can then 
be and'ed. Is this macro now deprecated?

-Steve

> +			if (field != AUDIT_MSGTYPE)
> +				return -30;
> +		} else
> +			switch(field) {
> +				case AUDIT_PID:
> +				case AUDIT_UID:
> +				case AUDIT_GID:
> +				case AUDIT_LOGINUID:
> +				case AUDIT_LOGINUID_SET:
> +				case AUDIT_MSGTYPE:
> +				case AUDIT_SUBJ_USER:
> +				case AUDIT_SUBJ_ROLE:
> +				case AUDIT_SUBJ_TYPE:
> +				case AUDIT_SUBJ_SEN:
> +				case AUDIT_SUBJ_CLR:
> +					break;
> +				default:
> +					return -12;
> +			}
> +	}
> 
>  	rule->fields[rule->field_count] = field;
>  	rule->fieldflags[rule->field_count] = op;
> diff --git a/trunk/lib/libaudit.h b/trunk/lib/libaudit.h
> index 0852bcc..f77691f 100644
> --- a/trunk/lib/libaudit.h
> +++ b/trunk/lib/libaudit.h
> @@ -278,6 +278,9 @@ extern "C" {
>  #ifndef AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH
>  #define AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH    0x00000004
>  #endif
> +#ifndef AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND
> +#define AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND	0x00000008
> +#endif
> 
>  /* Defines for interfield comparison update */
>  #ifndef AUDIT_OBJ_UID