On Fri, Mar 15, 2024 at 12:37:22PM +0100, Christian Göttsche wrote: > Introduce a new capable flag, CAP_OPT_NOAUDIT_ONDENY, to not generate > an audit event if the requested capability is not granted. This will be > used in a new capable_any() functionality to reduce the number of > necessary capable calls. > > Handle the flag accordingly in AppArmor and SELinux. > > CC: linux-block@xxxxxxxxxxxxxxx > Suggested-by: Paul Moore <paul@xxxxxxxxxxxxxx> > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx> Thanks. Reviewed-by: Serge Hallyn <serge@xxxxxxxxxx> > --- > v5: > rename flag to CAP_OPT_NOAUDIT_ONDENY, suggested by Serge: > https://lore.kernel.org/all/20230606190013.GA640488@xxxxxxxxxxxxxxx/ > --- > include/linux/security.h | 2 ++ > security/apparmor/capability.c | 8 +++++--- > security/selinux/hooks.c | 14 ++++++++------ > 3 files changed, 15 insertions(+), 9 deletions(-) > > diff --git a/include/linux/security.h b/include/linux/security.h > index 41a8f667bdfa..c60cae78ff8b 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -70,6 +70,8 @@ struct lsm_ctx; > #define CAP_OPT_NOAUDIT BIT(1) > /* If capable is being called by a setid function */ > #define CAP_OPT_INSETID BIT(2) > +/* If capable should audit the security request for authorized requests only */ > +#define CAP_OPT_NOAUDIT_ONDENY BIT(3) > > /* LSM Agnostic defines for security_sb_set_mnt_opts() flags */ > #define SECURITY_LSM_NATIVE_LABELS 1 > diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c > index 9934df16c843..08c9c9a0fc19 100644 > --- a/security/apparmor/capability.c > +++ b/security/apparmor/capability.c > @@ -108,7 +108,8 @@ static int audit_caps(struct apparmor_audit_data *ad, struct aa_profile *profile > * profile_capable - test if profile allows use of capability @cap > * @profile: profile being enforced (NOT NULL, NOT unconfined) > * @cap: capability to test if allowed > - * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated > + * @opts: CAP_OPT_NOAUDIT/CAP_OPT_NOAUDIT_ONDENY bit determines whether audit > + * record is generated > * @ad: audit data (MAY BE NULL indicating no auditing) > * > * Returns: 0 if allowed else -EPERM > @@ -126,7 +127,7 @@ static int profile_capable(struct aa_profile *profile, int cap, > else > error = -EPERM; > > - if (opts & CAP_OPT_NOAUDIT) { > + if ((opts & CAP_OPT_NOAUDIT) || ((opts & CAP_OPT_NOAUDIT_ONDENY) && error)) { > if (!COMPLAIN_MODE(profile)) > return error; > /* audit the cap request in complain mode but note that it > @@ -143,7 +144,8 @@ static int profile_capable(struct aa_profile *profile, int cap, > * @subj_cred: cred we are testing capability against > * @label: label being tested for capability (NOT NULL) > * @cap: capability to be tested > - * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated > + * @opts: CAP_OPT_NOAUDIT/CAP_OPT_NOAUDIT_ONDENY bit determines whether audit > + * record is generated > * > * Look up capability in profile capability set. > * > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 3448454c82d0..1a2c7c1a89be 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -1624,7 +1624,7 @@ static int cred_has_capability(const struct cred *cred, > u16 sclass; > u32 sid = cred_sid(cred); > u32 av = CAP_TO_MASK(cap); > - int rc; > + int rc, rc2; > > ad.type = LSM_AUDIT_DATA_CAP; > ad.u.cap = cap; > @@ -1643,11 +1643,13 @@ static int cred_has_capability(const struct cred *cred, > } > > rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); > - if (!(opts & CAP_OPT_NOAUDIT)) { > - int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); > - if (rc2) > - return rc2; > - } > + if ((opts & CAP_OPT_NOAUDIT) || ((opts & CAP_OPT_NOAUDIT_ONDENY) && rc)) > + return rc; > + > + rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); > + if (rc2) > + return rc2; > + > return rc; > } > > -- > 2.43.0 > >
