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: [email protected] Suggested-by: Paul Moore <[email protected]> Signed-off-by: Christian Göttsche <[email protected]> --- v5: rename flag to CAP_OPT_NOAUDIT_ONDENY, suggested by Serge: https://lore.kernel.org/all/[email protected]/ --- 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
