[userspace PATCH v2 2/2] Check exclude filter cred extension fields available in kernel
Richard Guy Briggs
rgb at redhat.com
Tue Oct 11 19:09:07 UTC 2016
On 2016-10-10 13:47, Steve Grubb wrote:
> On Thursday, August 18, 2016 2:33:20 PM EDT Richard Guy Briggs wrote:
> > Signed-off-by: Richard Guy Briggs <rgb at 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?
I was going to congratulate you on a nice catch, but
AUDIT_GET/SET_FEATURE and AUDIT_FEATURE_BITMAP are two different things.
The former gets and sets the state of features while the latter replaced
AUDIT_VERSION and simply checks for the presence of a backported
feature.
> -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
>
>
- RGB
--
Richard Guy Briggs <rgb at redhat.com>
Kernel Security Engineering, Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635
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