diff options
| -rw-r--r-- | security/selinux/avc.c | 52 |
1 files changed, 38 insertions, 14 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 6989472d0957..07620bc94e2a 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -741,6 +741,41 @@ int avc_ss_reset(u32 seqno) return rc; } +/* + * Slow-path helper function for avc_has_perm_noaudit, + * when the avc_node lookup fails. We get called with + * the RCU read lock held, and need to return with it + * still held, but drop if for the security compute. + * + * Don't inline this, since it's the slow-path and just + * results in a bigger stack frame. + */ +static noinline struct avc_node *avc_compute_av(u32 ssid, u32 tsid, + u16 tclass, struct av_decision *avd) +{ + rcu_read_unlock(); + security_compute_av(ssid, tsid, tclass, avd); + rcu_read_lock(); + return avc_insert(ssid, tsid, tclass, avd); +} + +static noinline int avc_denied(u32 ssid, u32 tsid, + u16 tclass, u32 requested, + unsigned flags, + struct av_decision *avd) +{ + if (flags & AVC_STRICT) + return -EACCES; + + if (selinux_enforcing && !(avd->flags & AVD_FLAGS_PERMISSIVE)) + return -EACCES; + + avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, + tsid, tclass, avd->seqno); + return 0; +} + + /** * avc_has_perm_noaudit - Check permissions but perform no auditing. * @ssid: source security identifier @@ -776,26 +811,15 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, node = avc_lookup(ssid, tsid, tclass); if (unlikely(!node)) { - rcu_read_unlock(); - security_compute_av(ssid, tsid, tclass, avd); - rcu_read_lock(); - node = avc_insert(ssid, tsid, tclass, avd); + node = avc_compute_av(ssid, tsid, tclass, avd); } else { memcpy(avd, &node->ae.avd, sizeof(*avd)); avd = &node->ae.avd; } denied = requested & ~(avd->allowed); - - if (denied) { - if (flags & AVC_STRICT) - rc = -EACCES; - else if (!selinux_enforcing || (avd->flags & AVD_FLAGS_PERMISSIVE)) - avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, - tsid, tclass, avd->seqno); - else - rc = -EACCES; - } + if (unlikely(denied)) + rc = avc_denied(ssid, tsid, tclass, requested, flags, avd); rcu_read_unlock(); return rc; |