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-rw-r--r--fs/ecryptfs/messaging.c81
1 files changed, 60 insertions, 21 deletions
diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
index c6038bd60897..1b5c20058acb 100644
--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -20,6 +20,8 @@
* 02111-1307, USA.
*/
#include <linux/sched.h>
+#include <linux/user_namespace.h>
+#include <linux/nsproxy.h>
#include "ecryptfs_kernel.h"
static LIST_HEAD(ecryptfs_msg_ctx_free_list);
@@ -103,6 +105,7 @@ void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx)
/**
* ecryptfs_find_daemon_by_euid
* @euid: The effective user id which maps to the desired daemon id
+ * @user_ns: The namespace in which @euid applies
* @daemon: If return value is zero, points to the desired daemon pointer
*
* Must be called with ecryptfs_daemon_hash_mux held.
@@ -111,7 +114,8 @@ void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx)
*
* Returns zero if the user id exists in the list; non-zero otherwise.
*/
-int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid)
+int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid,
+ struct user_namespace *user_ns)
{
struct hlist_node *elem;
int rc;
@@ -119,7 +123,7 @@ int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid)
hlist_for_each_entry(*daemon, elem,
&ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)],
euid_chain) {
- if ((*daemon)->euid == euid) {
+ if ((*daemon)->euid == euid && (*daemon)->user_ns == user_ns) {
rc = 0;
goto out;
}
@@ -186,6 +190,7 @@ out:
* ecryptfs_spawn_daemon - Create and initialize a new daemon struct
* @daemon: Pointer to set to newly allocated daemon struct
* @euid: Effective user id for the daemon
+ * @user_ns: The namespace in which @euid applies
* @pid: Process id for the daemon
*
* Must be called ceremoniously while in possession of
@@ -194,7 +199,8 @@ out:
* Returns zero on success; non-zero otherwise
*/
int
-ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid, pid_t pid)
+ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid,
+ struct user_namespace *user_ns, struct pid *pid)
{
int rc = 0;
@@ -206,7 +212,8 @@ ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid, pid_t pid)
goto out;
}
(*daemon)->euid = euid;
- (*daemon)->pid = pid;
+ (*daemon)->user_ns = get_user_ns(user_ns);
+ (*daemon)->pid = get_pid(pid);
(*daemon)->task = current;
mutex_init(&(*daemon)->mux);
INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue);
@@ -222,6 +229,7 @@ out:
* ecryptfs_process_helo
* @transport: The underlying transport (netlink, etc.)
* @euid: The user ID owner of the message
+ * @user_ns: The namespace in which @euid applies
* @pid: The process ID for the userspace program that sent the
* message
*
@@ -231,32 +239,33 @@ out:
* Returns zero after adding a new daemon to the hash list;
* non-zero otherwise.
*/
-int ecryptfs_process_helo(unsigned int transport, uid_t euid, pid_t pid)
+int ecryptfs_process_helo(unsigned int transport, uid_t euid,
+ struct user_namespace *user_ns, struct pid *pid)
{
struct ecryptfs_daemon *new_daemon;
struct ecryptfs_daemon *old_daemon;
int rc;
mutex_lock(&ecryptfs_daemon_hash_mux);
- rc = ecryptfs_find_daemon_by_euid(&old_daemon, euid);
+ rc = ecryptfs_find_daemon_by_euid(&old_daemon, euid, user_ns);
if (rc != 0) {
printk(KERN_WARNING "Received request from user [%d] "
- "to register daemon [%d]; unregistering daemon "
- "[%d]\n", euid, pid, old_daemon->pid);
+ "to register daemon [0x%p]; unregistering daemon "
+ "[0x%p]\n", euid, pid, old_daemon->pid);
rc = ecryptfs_send_raw_message(transport, ECRYPTFS_MSG_QUIT,
old_daemon);
if (rc)
printk(KERN_WARNING "Failed to send QUIT "
- "message to daemon [%d]; rc = [%d]\n",
+ "message to daemon [0x%p]; rc = [%d]\n",
old_daemon->pid, rc);
hlist_del(&old_daemon->euid_chain);
kfree(old_daemon);
}
- rc = ecryptfs_spawn_daemon(&new_daemon, euid, pid);
+ rc = ecryptfs_spawn_daemon(&new_daemon, euid, user_ns, pid);
if (rc)
printk(KERN_ERR "%s: The gods are displeased with this attempt "
- "to create a new daemon object for euid [%d]; pid [%d]; "
- "rc = [%d]\n", __func__, euid, pid, rc);
+ "to create a new daemon object for euid [%d]; pid "
+ "[0x%p]; rc = [%d]\n", __func__, euid, pid, rc);
mutex_unlock(&ecryptfs_daemon_hash_mux);
return rc;
}
@@ -277,7 +286,7 @@ int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon)
|| (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) {
rc = -EBUSY;
printk(KERN_WARNING "%s: Attempt to destroy daemon with pid "
- "[%d], but it is in the midst of a read or a poll\n",
+ "[0x%p], but it is in the midst of a read or a poll\n",
__func__, daemon->pid);
mutex_unlock(&daemon->mux);
goto out;
@@ -293,6 +302,10 @@ int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon)
hlist_del(&daemon->euid_chain);
if (daemon->task)
wake_up_process(daemon->task);
+ if (daemon->pid)
+ put_pid(daemon->pid);
+ if (daemon->user_ns)
+ put_user_ns(daemon->user_ns);
mutex_unlock(&daemon->mux);
memset(daemon, 0, sizeof(*daemon));
kfree(daemon);
@@ -303,6 +316,7 @@ out:
/**
* ecryptfs_process_quit
* @euid: The user ID owner of the message
+ * @user_ns: The namespace in which @euid applies
* @pid: The process ID for the userspace program that sent the
* message
*
@@ -310,17 +324,18 @@ out:
* it is the registered that is requesting the deletion. Returns zero
* after deleting the desired daemon; non-zero otherwise.
*/
-int ecryptfs_process_quit(uid_t euid, pid_t pid)
+int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns,
+ struct pid *pid)
{
struct ecryptfs_daemon *daemon;
int rc;
mutex_lock(&ecryptfs_daemon_hash_mux);
- rc = ecryptfs_find_daemon_by_euid(&daemon, euid);
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid, user_ns);
if (rc || !daemon) {
rc = -EINVAL;
printk(KERN_ERR "Received request from user [%d] to "
- "unregister unrecognized daemon [%d]\n", euid, pid);
+ "unregister unrecognized daemon [0x%p]\n", euid, pid);
goto out_unlock;
}
rc = ecryptfs_exorcise_daemon(daemon);
@@ -354,11 +369,14 @@ out_unlock:
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
- pid_t pid, u32 seq)
+ struct user_namespace *user_ns, struct pid *pid,
+ u32 seq)
{
struct ecryptfs_daemon *daemon;
struct ecryptfs_msg_ctx *msg_ctx;
size_t msg_size;
+ struct nsproxy *nsproxy;
+ struct user_namespace *current_user_ns;
int rc;
if (msg->index >= ecryptfs_message_buf_len) {
@@ -372,12 +390,25 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
msg_ctx = &ecryptfs_msg_ctx_arr[msg->index];
mutex_lock(&msg_ctx->mux);
mutex_lock(&ecryptfs_daemon_hash_mux);
- rc = ecryptfs_find_daemon_by_euid(&daemon, msg_ctx->task->euid);
+ rcu_read_lock();
+ nsproxy = task_nsproxy(msg_ctx->task);
+ if (nsproxy == NULL) {
+ rc = -EBADMSG;
+ printk(KERN_ERR "%s: Receiving process is a zombie. Dropping "
+ "message.\n", __func__);
+ rcu_read_unlock();
+ mutex_unlock(&ecryptfs_daemon_hash_mux);
+ goto wake_up;
+ }
+ current_user_ns = nsproxy->user_ns;
+ rc = ecryptfs_find_daemon_by_euid(&daemon, msg_ctx->task->euid,
+ current_user_ns);
+ rcu_read_unlock();
mutex_unlock(&ecryptfs_daemon_hash_mux);
if (rc) {
rc = -EBADMSG;
printk(KERN_WARNING "%s: User [%d] received a "
- "message response from process [%d] but does "
+ "message response from process [0x%p] but does "
"not have a registered daemon\n", __func__,
msg_ctx->task->euid, pid);
goto wake_up;
@@ -389,10 +420,17 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
euid, msg_ctx->task->euid);
goto unlock;
}
+ if (current_user_ns != user_ns) {
+ rc = -EBADMSG;
+ printk(KERN_WARNING "%s: Received message from user_ns "
+ "[0x%p]; expected message from user_ns [0x%p]\n",
+ __func__, user_ns, nsproxy->user_ns);
+ goto unlock;
+ }
if (daemon->pid != pid) {
rc = -EBADMSG;
printk(KERN_ERR "%s: User [%d] sent a message response "
- "from an unrecognized process [%d]\n",
+ "from an unrecognized process [0x%p]\n",
__func__, msg_ctx->task->euid, pid);
goto unlock;
}
@@ -446,7 +484,8 @@ ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
struct ecryptfs_daemon *daemon;
int rc;
- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid);
+ rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ current->nsproxy->user_ns);
if (rc || !daemon) {
rc = -ENOTCONN;
printk(KERN_ERR "%s: User [%d] does not have a daemon "
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 12:04:48 +0100