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Diffstat (limited to 'security')
-rw-r--r--security/commoncap.c25
-rw-r--r--security/device_cgroup.c20
-rw-r--r--security/keys/key.c6
-rw-r--r--security/keys/keyctl.c15
-rw-r--r--security/keys/keyring.c10
-rw-r--r--security/keys/process_keys.c94
-rw-r--r--security/keys/request_key.c21
-rw-r--r--security/selinux/nlmsgtab.c3
-rw-r--r--security/smack/Kconfig6
-rw-r--r--security/smack/smackfs.c17
-rw-r--r--security/yama/yama_lsm.c100
11 files changed, 198 insertions, 119 deletions
diff --git a/security/commoncap.c b/security/commoncap.c
index 6dbae4650abe..7ee08c756d6b 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -76,24 +76,33 @@ int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
int cap, int audit)
{
- for (;;) {
- /* The owner of the user namespace has all caps. */
- if (targ_ns != &init_user_ns && uid_eq(targ_ns->owner, cred->euid))
- return 0;
+ struct user_namespace *ns = targ_ns;
+ /* See if cred has the capability in the target user namespace
+ * by examining the target user namespace and all of the target
+ * user namespace's parents.
+ */
+ for (;;) {
/* Do we have the necessary capabilities? */
- if (targ_ns == cred->user_ns)
+ if (ns == cred->user_ns)
return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
/* Have we tried all of the parent namespaces? */
- if (targ_ns == &init_user_ns)
+ if (ns == &init_user_ns)
return -EPERM;
+ /*
+ * The owner of the user namespace in the parent of the
+ * user namespace has all caps.
+ */
+ if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid))
+ return 0;
+
/*
- *If you have a capability in a parent user ns, then you have
+ * If you have a capability in a parent user ns, then you have
* it over all children user namespaces as well.
*/
- targ_ns = targ_ns->parent;
+ ns = ns->parent;
}
/* We never get here */
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index b08d20c66c2e..19ecc8de9e6b 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -82,6 +82,8 @@ static int dev_exceptions_copy(struct list_head *dest, struct list_head *orig)
{
struct dev_exception_item *ex, *tmp, *new;
+ lockdep_assert_held(&devcgroup_mutex);
+
list_for_each_entry(ex, orig, list) {
new = kmemdup(ex, sizeof(*ex), GFP_KERNEL);
if (!new)
@@ -107,6 +109,8 @@ static int dev_exception_add(struct dev_cgroup *dev_cgroup,
{
struct dev_exception_item *excopy, *walk;
+ lockdep_assert_held(&devcgroup_mutex);
+
excopy = kmemdup(ex, sizeof(*ex), GFP_KERNEL);
if (!excopy)
return -ENOMEM;
@@ -137,6 +141,8 @@ static void dev_exception_rm(struct dev_cgroup *dev_cgroup,
{
struct dev_exception_item *walk, *tmp;
+ lockdep_assert_held(&devcgroup_mutex);
+
list_for_each_entry_safe(walk, tmp, &dev_cgroup->exceptions, list) {
if (walk->type != ex->type)
continue;
@@ -163,6 +169,8 @@ static void dev_exception_clean(struct dev_cgroup *dev_cgroup)
{
struct dev_exception_item *ex, *tmp;
+ lockdep_assert_held(&devcgroup_mutex);
+
list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) {
list_del_rcu(&ex->list);
kfree_rcu(ex, rcu);
@@ -172,7 +180,7 @@ static void dev_exception_clean(struct dev_cgroup *dev_cgroup)
/*
* called from kernel/cgroup.c with cgroup_lock() held.
*/
-static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup)
+static struct cgroup_subsys_state *devcgroup_css_alloc(struct cgroup *cgroup)
{
struct dev_cgroup *dev_cgroup, *parent_dev_cgroup;
struct cgroup *parent_cgroup;
@@ -202,7 +210,7 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup)
return &dev_cgroup->css;
}
-static void devcgroup_destroy(struct cgroup *cgroup)
+static void devcgroup_css_free(struct cgroup *cgroup)
{
struct dev_cgroup *dev_cgroup;
@@ -298,6 +306,10 @@ static int may_access(struct dev_cgroup *dev_cgroup,
struct dev_exception_item *ex;
bool match = false;
+ rcu_lockdep_assert(rcu_read_lock_held() ||
+ lockdep_is_held(&devcgroup_mutex),
+ "device_cgroup::may_access() called without proper synchronization");
+
list_for_each_entry_rcu(ex, &dev_cgroup->exceptions, list) {
if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK))
continue;
@@ -552,8 +564,8 @@ static struct cftype dev_cgroup_files[] = {
struct cgroup_subsys devices_subsys = {
.name = "devices",
.can_attach = devcgroup_can_attach,
- .create = devcgroup_create,
- .destroy = devcgroup_destroy,
+ .css_alloc = devcgroup_css_alloc,
+ .css_free = devcgroup_css_free,
.subsys_id = devices_subsys_id,
.base_cftypes = dev_cgroup_files,
diff --git a/security/keys/key.c b/security/keys/key.c
index a15c9da8f971..8fb7c7bd4657 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -854,13 +854,13 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
/* if the client doesn't provide, decide on the permissions we want */
if (perm == KEY_PERM_UNDEF) {
perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
- perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
+ perm |= KEY_USR_VIEW;
if (ktype->read)
- perm |= KEY_POS_READ | KEY_USR_READ;
+ perm |= KEY_POS_READ;
if (ktype == &key_type_keyring || ktype->update)
- perm |= KEY_USR_WRITE;
+ perm |= KEY_POS_WRITE;
}
/* allocate a new key */
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 5d34b4e827d6..4b5c948eb414 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1132,12 +1132,12 @@ long keyctl_instantiate_key_iov(key_serial_t id,
ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
ARRAY_SIZE(iovstack), iovstack, &iov);
if (ret < 0)
- return ret;
+ goto err;
if (ret == 0)
goto no_payload_free;
ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
-
+err:
if (iov != iovstack)
kfree(iov);
return ret;
@@ -1495,7 +1495,8 @@ long keyctl_session_to_parent(void)
goto error_keyring;
newwork = &cred->rcu;
- cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
+ cred->session_keyring = key_ref_to_ptr(keyring_r);
+ keyring_r = NULL;
init_task_work(newwork, key_change_session_keyring);
me = current;
@@ -1519,7 +1520,7 @@ long keyctl_session_to_parent(void)
mycred = current_cred();
pcred = __task_cred(parent);
if (mycred == pcred ||
- mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) {
+ mycred->session_keyring == pcred->session_keyring) {
ret = 0;
goto unlock;
}
@@ -1535,9 +1536,9 @@ long keyctl_session_to_parent(void)
goto unlock;
/* the keyrings must have the same UID */
- if ((pcred->tgcred->session_keyring &&
- !uid_eq(pcred->tgcred->session_keyring->uid, mycred->euid)) ||
- !uid_eq(mycred->tgcred->session_keyring->uid, mycred->euid))
+ if ((pcred->session_keyring &&
+ !uid_eq(pcred->session_keyring->uid, mycred->euid)) ||
+ !uid_eq(mycred->session_keyring->uid, mycred->euid))
goto unlock;
/* cancel an already pending keyring replacement */
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 6e42df15a24c..6ece7f2e5707 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -257,17 +257,14 @@ error:
* Allocate a keyring and link into the destination keyring.
*/
struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
- const struct cred *cred, unsigned long flags,
- struct key *dest)
+ const struct cred *cred, key_perm_t perm,
+ unsigned long flags, struct key *dest)
{
struct key *keyring;
int ret;
keyring = key_alloc(&key_type_keyring, description,
- uid, gid, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
- flags);
-
+ uid, gid, cred, perm, flags);
if (!IS_ERR(keyring)) {
ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
if (ret < 0) {
@@ -278,6 +275,7 @@ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
return keyring;
}
+EXPORT_SYMBOL(keyring_alloc);
/**
* keyring_search_aux - Search a keyring tree for a key matching some criteria
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index a58f712605d8..58dfe0890947 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -45,10 +45,12 @@ int install_user_keyrings(void)
struct user_struct *user;
const struct cred *cred;
struct key *uid_keyring, *session_keyring;
+ key_perm_t user_keyring_perm;
char buf[20];
int ret;
uid_t uid;
+ user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL;
cred = current_cred();
user = cred->user;
uid = from_kuid(cred->user_ns, user->uid);
@@ -73,8 +75,8 @@ int install_user_keyrings(void)
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID,
- cred, KEY_ALLOC_IN_QUOTA,
- NULL);
+ cred, user_keyring_perm,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
goto error;
@@ -89,7 +91,8 @@ int install_user_keyrings(void)
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, INVALID_GID,
- cred, KEY_ALLOC_IN_QUOTA, NULL);
+ cred, user_keyring_perm,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error_release;
@@ -130,6 +133,7 @@ int install_thread_keyring_to_cred(struct cred *new)
struct key *keyring;
keyring = keyring_alloc("_tid", new->uid, new->gid, new,
+ KEY_POS_ALL | KEY_USR_VIEW,
KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
@@ -170,27 +174,18 @@ static int install_thread_keyring(void)
int install_process_keyring_to_cred(struct cred *new)
{
struct key *keyring;
- int ret;
- if (new->tgcred->process_keyring)
+ if (new->process_keyring)
return -EEXIST;
- keyring = keyring_alloc("_pid", new->uid, new->gid,
- new, KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ keyring = keyring_alloc("_pid", new->uid, new->gid, new,
+ KEY_POS_ALL | KEY_USR_VIEW,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
- spin_lock_irq(&new->tgcred->lock);
- if (!new->tgcred->process_keyring) {
- new->tgcred->process_keyring = keyring;
- keyring = NULL;
- ret = 0;
- } else {
- ret = -EEXIST;
- }
- spin_unlock_irq(&new->tgcred->lock);
- key_put(keyring);
- return ret;
+ new->process_keyring = keyring;
+ return 0;
}
/*
@@ -231,11 +226,12 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
/* create an empty session keyring */
if (!keyring) {
flags = KEY_ALLOC_QUOTA_OVERRUN;
- if (cred->tgcred->session_keyring)
+ if (cred->session_keyring)
flags = KEY_ALLOC_IN_QUOTA;
- keyring = keyring_alloc("_ses", cred->uid, cred->gid,
- cred, flags, NULL);
+ keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
+ KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
+ flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
} else {
@@ -243,17 +239,11 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
}
/* install the keyring */
- spin_lock_irq(&cred->tgcred->lock);
- old = cred->tgcred->session_keyring;
- rcu_assign_pointer(cred->tgcred->session_keyring, keyring);
- spin_unlock_irq(&cred->tgcred->lock);
-
- /* we're using RCU on the pointer, but there's no point synchronising
- * on it if it didn't previously point to anything */
- if (old) {
- synchronize_rcu();
+ old = cred->session_keyring;
+ rcu_assign_pointer(cred->session_keyring, keyring);
+
+ if (old)
key_put(old);
- }
return 0;
}
@@ -358,8 +348,6 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
switch (PTR_ERR(key_ref)) {
case -EAGAIN: /* no key */
- if (ret)
- break;
case -ENOKEY: /* negative key */
ret = key_ref;
break;
@@ -370,9 +358,9 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
}
/* search the process keyring second */
- if (cred->tgcred->process_keyring) {
+ if (cred->process_keyring) {
key_ref = keyring_search_aux(
- make_key_ref(cred->tgcred->process_keyring, 1),
+ make_key_ref(cred->process_keyring, 1),
cred, type, description, match, no_state_check);
if (!IS_ERR(key_ref))
goto found;
@@ -391,12 +379,10 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
}
/* search the session keyring */
- if (cred->tgcred->session_keyring) {
+ if (cred->session_keyring) {
rcu_read_lock();
key_ref = keyring_search_aux(
- make_key_ref(rcu_dereference(
- cred->tgcred->session_keyring),
- 1),
+ make_key_ref(rcu_dereference(cred->session_keyring), 1),
cred, type, description, match, no_state_check);
rcu_read_unlock();
@@ -566,7 +552,7 @@ try_again:
break;
case KEY_SPEC_PROCESS_KEYRING:
- if (!cred->tgcred->process_keyring) {
+ if (!cred->process_keyring) {
if (!(lflags & KEY_LOOKUP_CREATE))
goto error;
@@ -578,13 +564,13 @@ try_again:
goto reget_creds;
}
- key = cred->tgcred->process_keyring;
+ key = cred->process_keyring;
atomic_inc(&key->usage);
key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_SESSION_KEYRING:
- if (!cred->tgcred->session_keyring) {
+ if (!cred->session_keyring) {
/* always install a session keyring upon access if one
* doesn't exist yet */
ret = install_user_keyrings();
@@ -599,7 +585,7 @@ try_again:
if (ret < 0)
goto error;
goto reget_creds;
- } else if (cred->tgcred->session_keyring ==
+ } else if (cred->session_keyring ==
cred->user->session_keyring &&
lflags & KEY_LOOKUP_CREATE) {
ret = join_session_keyring(NULL);
@@ -609,7 +595,7 @@ try_again:
}
rcu_read_lock();
- key = rcu_dereference(cred->tgcred->session_keyring);
+ key = rcu_dereference(cred->session_keyring);
atomic_inc(&key->usage);
rcu_read_unlock();
key_ref = make_key_ref(key, 1);
@@ -769,12 +755,6 @@ long join_session_keyring(const char *name)
struct key *keyring;
long ret, serial;
- /* only permit this if there's a single thread in the thread group -
- * this avoids us having to adjust the creds on all threads and risking
- * ENOMEM */
- if (!current_is_single_threaded())
- return -EMLINK;
-
new = prepare_creds();
if (!new)
return -ENOMEM;
@@ -786,7 +766,7 @@ long join_session_keyring(const char *name)
if (ret < 0)
goto error;
- serial = new->tgcred->session_keyring->serial;
+ serial = new->session_keyring->serial;
ret = commit_creds(new);
if (ret == 0)
ret = serial;
@@ -800,8 +780,10 @@ long join_session_keyring(const char *name)
keyring = find_keyring_by_name(name, false);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, old->uid, old->gid, old,
- KEY_ALLOC_IN_QUOTA, NULL);
+ keyring = keyring_alloc(
+ name, old->uid, old->gid, old,
+ KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
@@ -809,6 +791,9 @@ long join_session_keyring(const char *name)
} else if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
+ } else if (keyring == new->session_keyring) {
+ ret = 0;
+ goto error2;
}
/* we've got a keyring - now to install it */
@@ -865,8 +850,7 @@ void key_change_session_keyring(struct callback_head *twork)
new->jit_keyring = old->jit_keyring;
new->thread_keyring = key_get(old->thread_keyring);
- new->tgcred->tgid = old->tgcred->tgid;
- new->tgcred->process_keyring = key_get(old->tgcred->process_keyring);
+ new->process_keyring = key_get(old->process_keyring);
security_transfer_creds(new, old);
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 66e21184b559..4bd6bdb74193 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -126,6 +126,7 @@ static int call_sbin_request_key(struct key_construction *cons,
cred = get_current_cred();
keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
+ KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
KEY_ALLOC_QUOTA_OVERRUN, NULL);
put_cred(cred);
if (IS_ERR(keyring)) {
@@ -150,12 +151,12 @@ static int call_sbin_request_key(struct key_construction *cons,
cred->thread_keyring ? cred->thread_keyring->serial : 0);
prkey = 0;
- if (cred->tgcred->process_keyring)
- prkey = cred->tgcred->process_keyring->serial;
+ if (cred->process_keyring)
+ prkey = cred->process_keyring->serial;
sprintf(keyring_str[1], "%d", prkey);
rcu_read_lock();
- session = rcu_dereference(cred->tgcred->session_keyring);
+ session = rcu_dereference(cred->session_keyring);
if (!session)
session = cred->user->session_keyring;
sskey = session->serial;
@@ -297,14 +298,14 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- dest_keyring = key_get(cred->tgcred->process_keyring);
+ dest_keyring = key_get(cred->process_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
rcu_read_lock();
dest_keyring = key_get(
- rcu_dereference(cred->tgcred->session_keyring));
+ rcu_dereference(cred->session_keyring));
rcu_read_unlock();
if (dest_keyring)
@@ -347,6 +348,7 @@ static int construct_alloc_key(struct key_type *type,
const struct cred *cred = current_cred();
unsigned long prealloc;
struct key *key;
+ key_perm_t perm;
key_ref_t key_ref;
int ret;
@@ -355,8 +357,15 @@ static int construct_alloc_key(struct key_type *type,
*_key = NULL;
mutex_lock(&user->cons_lock);
+ perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+ perm |= KEY_USR_VIEW;
+ if (type->read)
+ perm |= KEY_POS_READ;
+ if (type == &key_type_keyring || type->update)
+ perm |= KEY_POS_WRITE;
+
key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
- KEY_POS_ALL, flags);
+ perm, flags);
if (IS_ERR(key))
goto alloc_failed;
diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index d309e7f472d8..370a6468b3ba 100644
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -67,6 +67,9 @@ static struct nlmsg_perm nlmsg_route_perms[] =
{ RTM_GETADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_READ },
{ RTM_GETDCB, NETLINK_ROUTE_SOCKET__NLMSG_READ },
{ RTM_SETDCB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+ { RTM_NEWNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+ { RTM_GETNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_READ },
+ { RTM_GETMDB, NETLINK_ROUTE_SOCKET__NLMSG_READ },
};
static struct nlmsg_perm nlmsg_tcpdiag_perms[] =
diff --git a/security/smack/Kconfig b/security/smack/Kconfig
index 603b08784341..e69de9c642b7 100644
--- a/security/smack/Kconfig
+++ b/security/smack/Kconfig
@@ -1,6 +1,10 @@
config SECURITY_SMACK
bool "Simplified Mandatory Access Control Kernel Support"
- depends on NETLABEL && SECURITY_NETWORK
+ depends on NET
+ depends on INET
+ depends on SECURITY
+ select NETLABEL
+ select SECURITY_NETWORK
default n
help
This selects the Simplified Mandatory Access Control Kernel.
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 99929a50093a..76a5dca46404 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -2063,6 +2063,19 @@ static const struct file_operations smk_revoke_subj_ops = {
.llseek = generic_file_llseek,
};
+static struct kset *smackfs_kset;
+/**
+ * smk_init_sysfs - initialize /sys/fs/smackfs
+ *
+ */
+static int smk_init_sysfs(void)
+{
+ smackfs_kset = kset_create_and_add("smackfs", NULL, fs_kobj);
+ if (!smackfs_kset)
+ return -ENOMEM;
+ return 0;
+}
+
/**
* smk_fill_super - fill the /smackfs superblock
* @sb: the empty superblock
@@ -2183,6 +2196,10 @@ static int __init init_smk_fs(void)
if (!security_module_enable(&smack_ops))
return 0;
+ err = smk_init_sysfs();
+ if (err)
+ printk(KERN_ERR "smackfs: sysfs mountpoint problem.\n");
+
err = register_filesystem(&smk_fs_type);
if (!err) {
smackfs_mount = kern_mount(&smk_fs_type);
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index b4c29848b49d..23414b93771f 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -17,6 +17,7 @@
#include <linux/ptrace.h>
#include <linux/prctl.h>
#include <linux/ratelimit.h>
+#include <linux/workqueue.h>
#define YAMA_SCOPE_DISABLED 0
#define YAMA_SCOPE_RELATIONAL 1
@@ -29,12 +30,37 @@ static int ptrace_scope = YAMA_SCOPE_RELATIONAL;
struct ptrace_relation {
struct task_struct *tracer;
struct task_struct *tracee;
+ bool invalid;
struct list_head node;
+ struct rcu_head rcu;
};
static LIST_HEAD(ptracer_relations);
static DEFINE_SPINLOCK(ptracer_relations_lock);
+static void yama_relation_cleanup(struct work_struct *work);
+static DECLARE_WORK(yama_relation_work, yama_relation_cleanup);
+
+/**
+ * yama_relation_cleanup - remove invalid entries from the relation list
+ *
+ */
+static void yama_relation_cleanup(struct work_struct *work)
+{
+ struct ptrace_relation *relation;
+
+ spin_lock(&ptracer_relations_lock);
+ rcu_read_lock();
+ list_for_each_entry_rcu(relation, &ptracer_relations, node) {
+ if (relation->invalid) {
+ list_del_rcu(&relation->node);
+ kfree_rcu(relation, rcu);
+ }
+ }
+ rcu_read_unlock();
+ spin_unlock(&ptracer_relations_lock);
+}
+
/**
* yama_ptracer_add - add/replace an exception for this tracer/tracee pair
* @tracer: the task_struct of the process doing the ptrace
@@ -48,32 +74,34 @@ static DEFINE_SPINLOCK(ptracer_relations_lock);
static int yama_ptracer_add(struct task_struct *tracer,
struct task_struct *tracee)
{
- int rc = 0;
- struct ptrace_relation *added;
- struct ptrace_relation *entry, *relation = NULL;
+ struct ptrace_relation *relation, *added;
added = kmalloc(sizeof(*added), GFP_KERNEL);
if (!added)
return -ENOMEM;
- spin_lock_bh(&ptracer_relations_lock);
- list_for_each_entry(entry, &ptracer_relations, node)
- if (entry->tracee == tracee) {
- relation = entry;
- break;
+ added->tracee = tracee;
+ added->tracer = tracer;
+ added->invalid = false;
+
+ spin_lock(&ptracer_relations_lock);
+ rcu_read_lock();
+ list_for_each_entry_rcu(relation, &ptracer_relations, node) {
+ if (relation->invalid)
+ continue;
+ if (relation->tracee == tracee) {
+ list_replace_rcu(&relation->node, &added->node);
+ kfree_rcu(relation, rcu);
+ goto out;
}
- if (!relation) {
- relation = added;
- relation->tracee = tracee;
- list_add(&relation->node, &ptracer_relations);
}
- relation->tracer = tracer;
- spin_unlock_bh(&ptracer_relations_lock);
- if (added != relation)
- kfree(added);
+ list_add_rcu(&added->node, &ptracer_relations);
- return rc;
+out:
+ rcu_read_unlock();
+ spin_unlock(&ptracer_relations_lock);
+ return 0;
}
/**
@@ -84,16 +112,23 @@ static int yama_ptracer_add(struct task_struct *tracer,
static void yama_ptracer_del(struct task_struct *tracer,
struct task_struct *tracee)
{
- struct ptrace_relation *relation, *safe;
+ struct ptrace_relation *relation;
+ bool marked = false;
- spin_lock_bh(&ptracer_relations_lock);
- list_for_each_entry_safe(relation, safe, &ptracer_relations, node)
+ rcu_read_lock();
+ list_for_each_entry_rcu(relation, &ptracer_relations, node) {
+ if (relation->invalid)
+ continue;
if (relation->tracee == tracee ||
(tracer && relation->tracer == tracer)) {
- list_del(&relation->node);
- kfree(relation);
+ relation->invalid = true;
+ marked = true;
}
- spin_unlock_bh(&ptracer_relations_lock);
+ }
+ rcu_read_unlock();
+
+ if (marked)
+ schedule_work(&yama_relation_work);
}
/**
@@ -217,21 +252,22 @@ static int ptracer_exception_found(struct task_struct *tracer,
struct task_struct *parent = NULL;
bool found = false;
- spin_lock_bh(&ptracer_relations_lock);
rcu_read_lock();
if (!thread_group_leader(tracee))
tracee = rcu_dereference(tracee->group_leader);
- list_for_each_entry(relation, &ptracer_relations, node)
+ list_for_each_entry_rcu(relation, &ptracer_relations, node) {
+ if (relation->invalid)
+ continue;
if (relation->tracee == tracee) {
parent = relation->tracer;
found = true;
break;
}
+ }
if (found && (parent == NULL || task_is_descendant(parent, tracer)))
rc = 1;
rcu_read_unlock();
- spin_unlock_bh(&ptracer_relations_lock);
return rc;
}
@@ -262,14 +298,18 @@ int yama_ptrace_access_check(struct task_struct *child,
/* No additional restrictions. */
break;
case YAMA_SCOPE_RELATIONAL:
+ rcu_read_lock();
if (!task_is_descendant(current, child) &&
!ptracer_exception_found(current, child) &&
- !ns_capable(task_user_ns(child), CAP_SYS_PTRACE))
+ !ns_capable(__task_cred(child)->user_ns, CAP_SYS_PTRACE))
rc = -EPERM;
+ rcu_read_unlock();
break;
case YAMA_SCOPE_CAPABILITY:
- if (!ns_capable(task_user_ns(child), CAP_SYS_PTRACE))
+ rcu_read_lock();
+ if (!ns_capable(__task_cred(child)->user_ns, CAP_SYS_PTRACE))
rc = -EPERM;
+ rcu_read_unlock();
break;
case YAMA_SCOPE_NO_ATTACH:
default:
@@ -307,8 +347,10 @@ int yama_ptrace_traceme(struct task_struct *parent)
/* Only disallow PTRACE_TRACEME on more aggressive settings. */
switch (ptrace_scope) {
case YAMA_SCOPE_CAPABILITY:
- if (!ns_capable(task_user_ns(parent), CAP_SYS_PTRACE))
+ rcu_read_lock();
+ if (!ns_capable(__task_cred(parent)->user_ns, CAP_SYS_PTRACE))
rc = -EPERM;
+ rcu_read_unlock();
break;
case YAMA_SCOPE_NO_ATTACH:
rc = -EPERM;
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-09 08:41:13 +0000