Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 635e5c1..ecd3829 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Implementation of the kernel access vector cache (AVC).
*
@@ -8,10 +9,6 @@
* Replaced the avc_lock spinlock by RCU.
*
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2,
- * as published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/stddef.h>
@@ -130,75 +127,6 @@
}
/**
- * avc_dump_av - Display an access vector in human-readable form.
- * @tclass: target security class
- * @av: access vector
- */
-static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
-{
- const char **perms;
- int i, perm;
-
- if (av == 0) {
- audit_log_format(ab, " null");
- return;
- }
-
- BUG_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map));
- perms = secclass_map[tclass-1].perms;
-
- audit_log_format(ab, " {");
- i = 0;
- perm = 1;
- while (i < (sizeof(av) * 8)) {
- if ((perm & av) && perms[i]) {
- audit_log_format(ab, " %s", perms[i]);
- av &= ~perm;
- }
- i++;
- perm <<= 1;
- }
-
- if (av)
- audit_log_format(ab, " 0x%x", av);
-
- audit_log_format(ab, " }");
-}
-
-/**
- * avc_dump_query - Display a SID pair and a class in human-readable form.
- * @ssid: source security identifier
- * @tsid: target security identifier
- * @tclass: target security class
- */
-static void avc_dump_query(struct audit_buffer *ab, struct selinux_state *state,
- u32 ssid, u32 tsid, u16 tclass)
-{
- int rc;
- char *scontext;
- u32 scontext_len;
-
- rc = security_sid_to_context(state, ssid, &scontext, &scontext_len);
- if (rc)
- audit_log_format(ab, "ssid=%d", ssid);
- else {
- audit_log_format(ab, "scontext=%s", scontext);
- kfree(scontext);
- }
-
- rc = security_sid_to_context(state, tsid, &scontext, &scontext_len);
- if (rc)
- audit_log_format(ab, " tsid=%d", tsid);
- else {
- audit_log_format(ab, " tcontext=%s", scontext);
- kfree(scontext);
- }
-
- BUG_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map));
- audit_log_format(ab, " tclass=%s", secclass_map[tclass-1].name);
-}
-
-/**
* avc_init - Initialize the AVC.
*
* Initialize the access vector cache.
@@ -735,11 +663,36 @@
static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
{
struct common_audit_data *ad = a;
- audit_log_format(ab, "avc: %s ",
- ad->selinux_audit_data->denied ? "denied" : "granted");
- avc_dump_av(ab, ad->selinux_audit_data->tclass,
- ad->selinux_audit_data->audited);
- audit_log_format(ab, " for ");
+ struct selinux_audit_data *sad = ad->selinux_audit_data;
+ u32 av = sad->audited;
+ const char **perms;
+ int i, perm;
+
+ audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted");
+
+ if (av == 0) {
+ audit_log_format(ab, " null");
+ return;
+ }
+
+ perms = secclass_map[sad->tclass-1].perms;
+
+ audit_log_format(ab, " {");
+ i = 0;
+ perm = 1;
+ while (i < (sizeof(av) * 8)) {
+ if ((perm & av) && perms[i]) {
+ audit_log_format(ab, " %s", perms[i]);
+ av &= ~perm;
+ }
+ i++;
+ perm <<= 1;
+ }
+
+ if (av)
+ audit_log_format(ab, " 0x%x", av);
+
+ audit_log_format(ab, " } for ");
}
/**
@@ -751,14 +704,53 @@
static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
{
struct common_audit_data *ad = a;
- audit_log_format(ab, " ");
- avc_dump_query(ab, ad->selinux_audit_data->state,
- ad->selinux_audit_data->ssid,
- ad->selinux_audit_data->tsid,
- ad->selinux_audit_data->tclass);
- if (ad->selinux_audit_data->denied) {
- audit_log_format(ab, " permissive=%u",
- ad->selinux_audit_data->result ? 0 : 1);
+ struct selinux_audit_data *sad = ad->selinux_audit_data;
+ char *scontext;
+ u32 scontext_len;
+ int rc;
+
+ rc = security_sid_to_context(sad->state, sad->ssid, &scontext,
+ &scontext_len);
+ if (rc)
+ audit_log_format(ab, " ssid=%d", sad->ssid);
+ else {
+ audit_log_format(ab, " scontext=%s", scontext);
+ kfree(scontext);
+ }
+
+ rc = security_sid_to_context(sad->state, sad->tsid, &scontext,
+ &scontext_len);
+ if (rc)
+ audit_log_format(ab, " tsid=%d", sad->tsid);
+ else {
+ audit_log_format(ab, " tcontext=%s", scontext);
+ kfree(scontext);
+ }
+
+ audit_log_format(ab, " tclass=%s", secclass_map[sad->tclass-1].name);
+
+ if (sad->denied)
+ audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1);
+
+ /* in case of invalid context report also the actual context string */
+ rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext,
+ &scontext_len);
+ if (!rc && scontext) {
+ if (scontext_len && scontext[scontext_len - 1] == '\0')
+ scontext_len--;
+ audit_log_format(ab, " srawcon=");
+ audit_log_n_untrustedstring(ab, scontext, scontext_len);
+ kfree(scontext);
+ }
+
+ rc = security_sid_to_context_inval(sad->state, sad->tsid, &scontext,
+ &scontext_len);
+ if (!rc && scontext) {
+ if (scontext_len && scontext[scontext_len - 1] == '\0')
+ scontext_len--;
+ audit_log_format(ab, " trawcon=");
+ audit_log_n_untrustedstring(ab, scontext, scontext_len);
+ kfree(scontext);
}
}
@@ -772,6 +764,9 @@
struct common_audit_data stack_data;
struct selinux_audit_data sad;
+ if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map)))
+ return -EINVAL;
+
if (!a) {
a = &stack_data;
a->type = LSM_AUDIT_DATA_NONE;
@@ -838,6 +833,7 @@
* @ssid,@tsid,@tclass : identifier of an AVC entry
* @seqno : sequence number when decision was made
* @xpd: extended_perms_decision to be added to the node
+ * @flags: the AVC_* flags, e.g. AVC_NONBLOCKING, AVC_EXTENDED_PERMS, or 0.
*
* if a valid AVC entry doesn't exist,this function returns -ENOENT.
* if kmalloc() called internal returns NULL, this function returns -ENOMEM.
@@ -856,6 +852,22 @@
struct hlist_head *head;
spinlock_t *lock;
+ /*
+ * If we are in a non-blocking code path, e.g. VFS RCU walk,
+ * then we must not add permissions to a cache entry
+ * because we cannot safely audit the denial. Otherwise,
+ * during the subsequent blocking retry (e.g. VFS ref walk), we
+ * will find the permissions already granted in the cache entry
+ * and won't audit anything at all, leading to silent denials in
+ * permissive mode that only appear when in enforcing mode.
+ *
+ * See the corresponding handling in slow_avc_audit(), and the
+ * logic in selinux_inode_permission for the MAY_NOT_BLOCK flag,
+ * which is transliterated into AVC_NONBLOCKING.
+ */
+ if (flags & AVC_NONBLOCKING)
+ return 0;
+
node = avc_alloc_node(avc);
if (!node) {
rc = -ENOMEM;
@@ -1050,7 +1062,8 @@
int rc = 0, rc2;
xp_node = &local_xp_node;
- BUG_ON(!requested);
+ if (WARN_ON(!requested))
+ return -EACCES;
rcu_read_lock();
@@ -1115,7 +1128,7 @@
* @tsid: target security identifier
* @tclass: target security class
* @requested: requested permissions, interpreted based on @tclass
- * @flags: AVC_STRICT or 0
+ * @flags: AVC_STRICT, AVC_NONBLOCKING, or 0
* @avd: access vector decisions
*
* Check the AVC to determine whether the @requested permissions are granted
@@ -1140,7 +1153,8 @@
int rc = 0;
u32 denied;
- BUG_ON(!requested);
+ if (WARN_ON(!requested))
+ return -EACCES;
rcu_read_lock();
@@ -1191,24 +1205,6 @@
return rc;
}
-int avc_has_perm_flags(struct selinux_state *state,
- u32 ssid, u32 tsid, u16 tclass, u32 requested,
- struct common_audit_data *auditdata,
- int flags)
-{
- struct av_decision avd;
- int rc, rc2;
-
- rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested, 0,
- &avd);
-
- rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc,
- auditdata, flags);
- if (rc2)
- return rc2;
- return rc;
-}
-
u32 avc_policy_seqno(struct selinux_state *state)
{
return state->avc->avc_cache.latest_notif;