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Diffstat (limited to 'security/apparmor/lsm.c')
-rw-r--r--security/apparmor/lsm.c305
1 files changed, 284 insertions, 21 deletions
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 366cdfd6a7..608a849a74 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -49,12 +49,19 @@ union aa_buffer {
DECLARE_FLEX_ARRAY(char, buffer);
};
+struct aa_local_cache {
+ unsigned int hold;
+ unsigned int count;
+ struct list_head head;
+};
+
#define RESERVE_COUNT 2
static int reserve_count = RESERVE_COUNT;
static int buffer_count;
static LIST_HEAD(aa_global_buffers);
static DEFINE_SPINLOCK(aa_buffers_lock);
+static DEFINE_PER_CPU(struct aa_local_cache, aa_local_buffers);
/*
* LSM hook functions
@@ -582,6 +589,114 @@ static int apparmor_file_mprotect(struct vm_area_struct *vma,
false);
}
+#ifdef CONFIG_IO_URING
+static const char *audit_uring_mask(u32 mask)
+{
+ if (mask & AA_MAY_CREATE_SQPOLL)
+ return "sqpoll";
+ if (mask & AA_MAY_OVERRIDE_CRED)
+ return "override_creds";
+ return "";
+}
+
+static void audit_uring_cb(struct audit_buffer *ab, void *va)
+{
+ struct apparmor_audit_data *ad = aad_of_va(va);
+
+ if (ad->request & AA_URING_PERM_MASK) {
+ audit_log_format(ab, " requested=\"%s\"",
+ audit_uring_mask(ad->request));
+ if (ad->denied & AA_URING_PERM_MASK) {
+ audit_log_format(ab, " denied=\"%s\"",
+ audit_uring_mask(ad->denied));
+ }
+ }
+ if (ad->uring.target) {
+ audit_log_format(ab, " tcontext=");
+ aa_label_xaudit(ab, labels_ns(ad->subj_label),
+ ad->uring.target,
+ FLAGS_NONE, GFP_ATOMIC);
+ }
+}
+
+static int profile_uring(struct aa_profile *profile, u32 request,
+ struct aa_label *new, int cap,
+ struct apparmor_audit_data *ad)
+{
+ unsigned int state;
+ struct aa_ruleset *rules;
+ int error = 0;
+
+ AA_BUG(!profile);
+
+ rules = list_first_entry(&profile->rules, typeof(*rules), list);
+ state = RULE_MEDIATES(rules, AA_CLASS_IO_URING);
+ if (state) {
+ struct aa_perms perms = { };
+
+ if (new) {
+ aa_label_match(profile, rules, new, state,
+ false, request, &perms);
+ } else {
+ perms = *aa_lookup_perms(rules->policy, state);
+ }
+ aa_apply_modes_to_perms(profile, &perms);
+ error = aa_check_perms(profile, &perms, request, ad,
+ audit_uring_cb);
+ }
+
+ return error;
+}
+
+/**
+ * apparmor_uring_override_creds - check the requested cred override
+ * @new: the target creds
+ *
+ * Check to see if the current task is allowed to override it's credentials
+ * to service an io_uring operation.
+ */
+static int apparmor_uring_override_creds(const struct cred *new)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error;
+ DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
+ OP_URING_OVERRIDE);
+
+ ad.uring.target = cred_label(new);
+ label = __begin_current_label_crit_section();
+ error = fn_for_each(label, profile,
+ profile_uring(profile, AA_MAY_OVERRIDE_CRED,
+ cred_label(new), CAP_SYS_ADMIN, &ad));
+ __end_current_label_crit_section(label);
+
+ return error;
+}
+
+/**
+ * apparmor_uring_sqpoll - check if a io_uring polling thread can be created
+ *
+ * Check to see if the current task is allowed to create a new io_uring
+ * kernel polling thread.
+ */
+static int apparmor_uring_sqpoll(void)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error;
+ DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
+ OP_URING_SQPOLL);
+
+ label = __begin_current_label_crit_section();
+ error = fn_for_each(label, profile,
+ profile_uring(profile, AA_MAY_CREATE_SQPOLL,
+ NULL, CAP_SYS_ADMIN, &ad));
+ __end_current_label_crit_section(label);
+
+ return error;
+}
+#endif /* CONFIG_IO_URING */
+
static int apparmor_sb_mount(const char *dev_name, const struct path *path,
const char *type, unsigned long flags, void *data)
{
@@ -765,7 +880,7 @@ fail:
* apparmor_bprm_committing_creds - do task cleanup on committing new creds
* @bprm: binprm for the exec (NOT NULL)
*/
-static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
+static void apparmor_bprm_committing_creds(const struct linux_binprm *bprm)
{
struct aa_label *label = aa_current_raw_label();
struct aa_label *new_label = cred_label(bprm->cred);
@@ -787,7 +902,7 @@ static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
* apparmor_bprm_committed_creds() - do cleanup after new creds committed
* @bprm: binprm for the exec (NOT NULL)
*/
-static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
+static void apparmor_bprm_committed_creds(const struct linux_binprm *bprm)
{
/* clear out temporary/transitional state from the context */
aa_clear_task_ctx_trans(task_ctx(current));
@@ -797,9 +912,9 @@ static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
static void apparmor_current_getsecid_subj(u32 *secid)
{
- struct aa_label *label = aa_get_current_label();
+ struct aa_label *label = __begin_current_label_crit_section();
*secid = label->secid;
- aa_put_label(label);
+ __end_current_label_crit_section(label);
}
static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid)
@@ -850,6 +965,27 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo
return error;
}
+static int apparmor_userns_create(const struct cred *cred)
+{
+ struct aa_label *label;
+ struct aa_profile *profile;
+ int error = 0;
+ DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_TASK, AA_CLASS_NS,
+ OP_USERNS_CREATE);
+
+ ad.subj_cred = current_cred();
+
+ label = begin_current_label_crit_section();
+ if (!unconfined(label)) {
+ error = fn_for_each(label, profile,
+ aa_profile_ns_perm(profile, &ad,
+ AA_USERNS_CREATE));
+ }
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
/**
* apparmor_sk_alloc_security - allocate and attach the sk_security field
*/
@@ -861,7 +997,7 @@ static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
if (!ctx)
return -ENOMEM;
- SK_CTX(sk) = ctx;
+ sk->sk_security = ctx;
return 0;
}
@@ -871,9 +1007,9 @@ static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
*/
static void apparmor_sk_free_security(struct sock *sk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
- SK_CTX(sk) = NULL;
+ sk->sk_security = NULL;
aa_put_label(ctx->label);
aa_put_label(ctx->peer);
kfree(ctx);
@@ -885,8 +1021,8 @@ static void apparmor_sk_free_security(struct sock *sk)
static void apparmor_sk_clone_security(const struct sock *sk,
struct sock *newsk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
- struct aa_sk_ctx *new = SK_CTX(newsk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
+ struct aa_sk_ctx *new = aa_sock(newsk);
if (new->label)
aa_put_label(new->label);
@@ -940,7 +1076,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family,
label = aa_get_current_label();
if (sock->sk) {
- struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
+ struct aa_sk_ctx *ctx = aa_sock(sock->sk);
aa_put_label(ctx->label);
ctx->label = aa_get_label(label);
@@ -1125,7 +1261,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
*/
static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
if (!skb->secmark)
return 0;
@@ -1138,7 +1274,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
static struct aa_label *sk_peer_label(struct sock *sk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
if (ctx->peer)
return ctx->peer;
@@ -1219,7 +1355,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock,
*/
static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
if (!ctx->label)
ctx->label = aa_get_current_label();
@@ -1229,7 +1365,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
if (!skb->secmark)
return 0;
@@ -1328,6 +1464,7 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj),
LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
LSM_HOOK_INIT(task_kill, apparmor_task_kill),
+ LSM_HOOK_INIT(userns_create, apparmor_userns_create),
#ifdef CONFIG_AUDIT
LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
@@ -1339,6 +1476,11 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
+
+#ifdef CONFIG_IO_URING
+ LSM_HOOK_INIT(uring_override_creds, apparmor_uring_override_creds),
+ LSM_HOOK_INIT(uring_sqpoll, apparmor_uring_sqpoll),
+#endif
};
/*
@@ -1669,11 +1811,32 @@ static int param_set_mode(const char *val, const struct kernel_param *kp)
char *aa_get_buffer(bool in_atomic)
{
union aa_buffer *aa_buf;
+ struct aa_local_cache *cache;
bool try_again = true;
gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+ /* use per cpu cached buffers first */
+ cache = get_cpu_ptr(&aa_local_buffers);
+ if (!list_empty(&cache->head)) {
+ aa_buf = list_first_entry(&cache->head, union aa_buffer, list);
+ list_del(&aa_buf->list);
+ cache->hold--;
+ cache->count--;
+ put_cpu_ptr(&aa_local_buffers);
+ return &aa_buf->buffer[0];
+ }
+ put_cpu_ptr(&aa_local_buffers);
+
+ if (!spin_trylock(&aa_buffers_lock)) {
+ cache = get_cpu_ptr(&aa_local_buffers);
+ cache->hold += 1;
+ put_cpu_ptr(&aa_local_buffers);
+ spin_lock(&aa_buffers_lock);
+ } else {
+ cache = get_cpu_ptr(&aa_local_buffers);
+ put_cpu_ptr(&aa_local_buffers);
+ }
retry:
- spin_lock(&aa_buffers_lock);
if (buffer_count > reserve_count ||
(in_atomic && !list_empty(&aa_global_buffers))) {
aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
@@ -1699,6 +1862,7 @@ retry:
if (!aa_buf) {
if (try_again) {
try_again = false;
+ spin_lock(&aa_buffers_lock);
goto retry;
}
pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
@@ -1710,15 +1874,34 @@ retry:
void aa_put_buffer(char *buf)
{
union aa_buffer *aa_buf;
+ struct aa_local_cache *cache;
if (!buf)
return;
aa_buf = container_of(buf, union aa_buffer, buffer[0]);
- spin_lock(&aa_buffers_lock);
- list_add(&aa_buf->list, &aa_global_buffers);
- buffer_count++;
- spin_unlock(&aa_buffers_lock);
+ cache = get_cpu_ptr(&aa_local_buffers);
+ if (!cache->hold) {
+ put_cpu_ptr(&aa_local_buffers);
+
+ if (spin_trylock(&aa_buffers_lock)) {
+ /* put back on global list */
+ list_add(&aa_buf->list, &aa_global_buffers);
+ buffer_count++;
+ spin_unlock(&aa_buffers_lock);
+ cache = get_cpu_ptr(&aa_local_buffers);
+ put_cpu_ptr(&aa_local_buffers);
+ return;
+ }
+ /* contention on global list, fallback to percpu */
+ cache = get_cpu_ptr(&aa_local_buffers);
+ cache->hold += 1;
+ }
+
+ /* cache in percpu list */
+ list_add(&aa_buf->list, &cache->head);
+ cache->count++;
+ put_cpu_ptr(&aa_local_buffers);
}
/*
@@ -1761,6 +1944,15 @@ static int __init alloc_buffers(void)
int i, num;
/*
+ * per cpu set of cached allocated buffers used to help reduce
+ * lock contention
+ */
+ for_each_possible_cpu(i) {
+ per_cpu(aa_local_buffers, i).hold = 0;
+ per_cpu(aa_local_buffers, i).count = 0;
+ INIT_LIST_HEAD(&per_cpu(aa_local_buffers, i).head);
+ }
+ /*
* A function may require two buffers at once. Usually the buffers are
* used for a short period of time and are shared. On UP kernel buffers
* two should be enough, with more CPUs it is possible that more
@@ -1799,6 +1991,7 @@ static int apparmor_dointvec(struct ctl_table *table, int write,
}
static struct ctl_table apparmor_sysctl_table[] = {
+#ifdef CONFIG_USER_NS
{
.procname = "unprivileged_userns_apparmor_policy",
.data = &unprivileged_userns_apparmor_policy,
@@ -1806,6 +1999,7 @@ static struct ctl_table apparmor_sysctl_table[] = {
.mode = 0600,
.proc_handler = apparmor_dointvec,
},
+#endif /* CONFIG_USER_NS */
{
.procname = "apparmor_display_secid_mode",
.data = &apparmor_display_secid_mode,
@@ -1813,7 +2007,13 @@ static struct ctl_table apparmor_sysctl_table[] = {
.mode = 0600,
.proc_handler = apparmor_dointvec,
},
-
+ {
+ .procname = "apparmor_restrict_unprivileged_unconfined",
+ .data = &aa_unprivileged_unconfined_restricted,
+ .maxlen = sizeof(int),
+ .mode = 0600,
+ .proc_handler = apparmor_dointvec,
+ },
{ }
};
@@ -1843,7 +2043,7 @@ static unsigned int apparmor_ip_postroute(void *priv,
if (sk == NULL)
return NF_ACCEPT;
- ctx = SK_CTX(sk);
+ ctx = aa_sock(sk);
if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
skb->secmark, sk))
return NF_ACCEPT;
@@ -1902,6 +2102,69 @@ static int __init apparmor_nf_ip_init(void)
__initcall(apparmor_nf_ip_init);
#endif
+static char nulldfa_src[] = {
+ #include "nulldfa.in"
+};
+struct aa_dfa *nulldfa;
+
+static char stacksplitdfa_src[] = {
+ #include "stacksplitdfa.in"
+};
+struct aa_dfa *stacksplitdfa;
+struct aa_policydb *nullpdb;
+
+static int __init aa_setup_dfa_engine(void)
+{
+ int error = -ENOMEM;
+
+ nullpdb = aa_alloc_pdb(GFP_KERNEL);
+ if (!nullpdb)
+ return -ENOMEM;
+
+ nulldfa = aa_dfa_unpack(nulldfa_src, sizeof(nulldfa_src),
+ TO_ACCEPT1_FLAG(YYTD_DATA32) |
+ TO_ACCEPT2_FLAG(YYTD_DATA32));
+ if (IS_ERR(nulldfa)) {
+ error = PTR_ERR(nulldfa);
+ goto fail;
+ }
+ nullpdb->dfa = aa_get_dfa(nulldfa);
+ nullpdb->perms = kcalloc(2, sizeof(struct aa_perms), GFP_KERNEL);
+ if (!nullpdb->perms)
+ goto fail;
+ nullpdb->size = 2;
+
+ stacksplitdfa = aa_dfa_unpack(stacksplitdfa_src,
+ sizeof(stacksplitdfa_src),
+ TO_ACCEPT1_FLAG(YYTD_DATA32) |
+ TO_ACCEPT2_FLAG(YYTD_DATA32));
+ if (IS_ERR(stacksplitdfa)) {
+ error = PTR_ERR(stacksplitdfa);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ aa_put_pdb(nullpdb);
+ aa_put_dfa(nulldfa);
+ nullpdb = NULL;
+ nulldfa = NULL;
+ stacksplitdfa = NULL;
+
+ return error;
+}
+
+static void __init aa_teardown_dfa_engine(void)
+{
+ aa_put_dfa(stacksplitdfa);
+ aa_put_dfa(nulldfa);
+ aa_put_pdb(nullpdb);
+ nullpdb = NULL;
+ stacksplitdfa = NULL;
+ nulldfa = NULL;
+}
+
static int __init apparmor_init(void)
{
int error;
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-08 16:27:17 +0000