1 files changed, 124 insertions, 138 deletions

diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 4ec8f61ccf5..e4141f25749 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -24,6 +24,7 @@
 #include <linux/random.h>
 #include <linux/miscdevice.h>
 #include <linux/poll.h>
+#include <linux/slab.h>
 #include <linux/wait.h>
 #include <linux/module.h>
 #include "ecryptfs_kernel.h"
@@ -32,7 +33,7 @@ static atomic_t ecryptfs_num_miscdev_opens;
 
 /**
  * ecryptfs_miscdev_poll
- * @file: dev file (ignored)
+ * @file: dev file
  * @pt: dev poll table (ignored)
  *
  * Returns the poll mask
@@ -40,17 +41,10 @@ static atomic_t ecryptfs_num_miscdev_opens;
 static unsigned int
 ecryptfs_miscdev_poll(struct file *file, poll_table *pt)
 {
-	struct ecryptfs_daemon *daemon;
+	struct ecryptfs_daemon *daemon = file->private_data;
 	unsigned int mask = 0;
-	uid_t euid = current_euid();
-	int rc;
 
-	mutex_lock(&ecryptfs_daemon_hash_mux);
-	/* TODO: Just use file->private_data? */
-	rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
-	BUG_ON(rc || !daemon);
 	mutex_lock(&daemon->mux);
-	mutex_unlock(&ecryptfs_daemon_hash_mux);
 	if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
 		printk(KERN_WARNING "%s: Attempt to poll on zombified "
 		       "daemon\n", __func__);
@@ -75,7 +69,7 @@ out_unlock_daemon:
 /**
  * ecryptfs_miscdev_open
  * @inode: inode of miscdev handle (ignored)
- * @file: file for miscdev handle (ignored)
+ * @file: file for miscdev handle
  *
  * Returns zero on success; non-zero otherwise
  */
@@ -83,50 +77,30 @@ static int
 ecryptfs_miscdev_open(struct inode *inode, struct file *file)
 {
 	struct ecryptfs_daemon *daemon = NULL;
-	uid_t euid = current_euid();
 	int rc;
 
 	mutex_lock(&ecryptfs_daemon_hash_mux);
-	rc = try_module_get(THIS_MODULE);
-	if (rc == 0) {
-		rc = -EIO;
-		printk(KERN_ERR "%s: Error attempting to increment module use "
-		       "count; rc = [%d]\n", __func__, rc);
+	rc = ecryptfs_find_daemon_by_euid(&daemon);
+	if (!rc) {
+		rc = -EINVAL;
 		goto out_unlock_daemon_list;
 	}
-	rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
-	if (rc || !daemon) {
-		rc = ecryptfs_spawn_daemon(&daemon, euid, current_user_ns(),
-					   task_pid(current));
-		if (rc) {
-			printk(KERN_ERR "%s: Error attempting to spawn daemon; "
-			       "rc = [%d]\n", __func__, rc);
-			goto out_module_put_unlock_daemon_list;
-		}
+	rc = ecryptfs_spawn_daemon(&daemon, file);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to spawn daemon; "
+		       "rc = [%d]\n", __func__, rc);
+		goto out_unlock_daemon_list;
 	}
 	mutex_lock(&daemon->mux);
-	if (daemon->pid != task_pid(current)) {
-		rc = -EINVAL;
-		printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], "
-		       "but pid [0x%p] has attempted to open the handle "
-		       "instead\n", __func__, daemon->pid, daemon->euid,
-		       task_pid(current));
-		goto out_unlock_daemon;
-	}
 	if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
 		rc = -EBUSY;
-		printk(KERN_ERR "%s: Miscellaneous device handle may only be "
-		       "opened once per daemon; pid [0x%p] already has this "
-		       "handle open\n", __func__, daemon->pid);
 		goto out_unlock_daemon;
 	}
 	daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN;
+	file->private_data = daemon;
 	atomic_inc(&ecryptfs_num_miscdev_opens);
 out_unlock_daemon:
 	mutex_unlock(&daemon->mux);
-out_module_put_unlock_daemon_list:
-	if (rc)
-		module_put(THIS_MODULE);
 out_unlock_daemon_list:
 	mutex_unlock(&ecryptfs_daemon_hash_mux);
 	return rc;
@@ -135,7 +109,7 @@ out_unlock_daemon_list:
 /**
  * ecryptfs_miscdev_release
  * @inode: inode of fs/ecryptfs/euid handle (ignored)
- * @file: file for fs/ecryptfs/euid handle (ignored)
+ * @file: file for fs/ecryptfs/euid handle
  *
  * This keeps the daemon registered until the daemon sends another
  * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters.
@@ -145,28 +119,24 @@ out_unlock_daemon_list:
 static int
 ecryptfs_miscdev_release(struct inode *inode, struct file *file)
 {
-	struct ecryptfs_daemon *daemon = NULL;
-	uid_t euid = current_euid();
+	struct ecryptfs_daemon *daemon = file->private_data;
 	int rc;
 
-	mutex_lock(&ecryptfs_daemon_hash_mux);
-	rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
-	BUG_ON(rc || !daemon);
 	mutex_lock(&daemon->mux);
-	BUG_ON(daemon->pid != task_pid(current));
 	BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN));
 	daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN;
 	atomic_dec(&ecryptfs_num_miscdev_opens);
 	mutex_unlock(&daemon->mux);
+
+	mutex_lock(&ecryptfs_daemon_hash_mux);
 	rc = ecryptfs_exorcise_daemon(daemon);
+	mutex_unlock(&ecryptfs_daemon_hash_mux);
 	if (rc) {
 		printk(KERN_CRIT "%s: Fatal error whilst attempting to "
 		       "shut down daemon; rc = [%d]. Please report this "
 		       "bug.\n", __func__, rc);
 		BUG();
 	}
-	module_put(THIS_MODULE);
-	mutex_unlock(&ecryptfs_daemon_hash_mux);
 	return rc;
 }
 
@@ -190,36 +160,60 @@ int ecryptfs_send_miscdev(char *data, size_t data_size,
 			  struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
 			  u16 msg_flags, struct ecryptfs_daemon *daemon)
 {
-	int rc = 0;
+	struct ecryptfs_message *msg;
 
-	mutex_lock(&msg_ctx->mux);
-	msg_ctx->msg = kmalloc((sizeof(*msg_ctx->msg) + data_size),
-			       GFP_KERNEL);
-	if (!msg_ctx->msg) {
-		rc = -ENOMEM;
+	msg = kmalloc((sizeof(*msg) + data_size), GFP_KERNEL);
+	if (!msg) {
 		printk(KERN_ERR "%s: Out of memory whilst attempting "
 		       "to kmalloc(%zd, GFP_KERNEL)\n", __func__,
-		       (sizeof(*msg_ctx->msg) + data_size));
-		goto out_unlock;
+		       (sizeof(*msg) + data_size));
+		return -ENOMEM;
 	}
+
+	mutex_lock(&msg_ctx->mux);
+	msg_ctx->msg = msg;
 	msg_ctx->msg->index = msg_ctx->index;
 	msg_ctx->msg->data_len = data_size;
 	msg_ctx->type = msg_type;
 	memcpy(msg_ctx->msg->data, data, data_size);
 	msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size);
-	mutex_lock(&daemon->mux);
 	list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue);
+	mutex_unlock(&msg_ctx->mux);
+
+	mutex_lock(&daemon->mux);
 	daemon->num_queued_msg_ctx++;
 	wake_up_interruptible(&daemon->wait);
 	mutex_unlock(&daemon->mux);
-out_unlock:
-	mutex_unlock(&msg_ctx->mux);
-	return rc;
+
+	return 0;
 }
 
+/*
+ * miscdevfs packet format:
+ *  Octet 0: Type
+ *  Octets 1-4: network byte order msg_ctx->counter
+ *  Octets 5-N0: Size of struct ecryptfs_message to follow
+ *  Octets N0-N1: struct ecryptfs_message (including data)
+ *
+ *  Octets 5-N1 not written if the packet type does not include a message
+ */
+#define PKT_TYPE_SIZE		1
+#define PKT_CTR_SIZE		4
+#define MIN_NON_MSG_PKT_SIZE	(PKT_TYPE_SIZE + PKT_CTR_SIZE)
+#define MIN_MSG_PKT_SIZE	(PKT_TYPE_SIZE + PKT_CTR_SIZE \
+				 + ECRYPTFS_MIN_PKT_LEN_SIZE)
+/* 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES comes from tag 65 packet format */
+#define MAX_MSG_PKT_SIZE	(PKT_TYPE_SIZE + PKT_CTR_SIZE \
+				 + ECRYPTFS_MAX_PKT_LEN_SIZE \
+				 + sizeof(struct ecryptfs_message) \
+				 + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES)
+#define PKT_TYPE_OFFSET		0
+#define PKT_CTR_OFFSET		PKT_TYPE_SIZE
+#define PKT_LEN_OFFSET		(PKT_TYPE_SIZE + PKT_CTR_SIZE)
+
 /**
  * ecryptfs_miscdev_read - format and send message from queue
- * @file: fs/ecryptfs/euid miscdevfs handle (ignored)
+ * @file: miscdevfs handle
  * @buf: User buffer into which to copy the next message on the daemon queue
  * @count: Amount of space available in @buf
  * @ppos: Offset in file (ignored)
@@ -233,35 +227,27 @@ static ssize_t
 ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
 		      loff_t *ppos)
 {
-	struct ecryptfs_daemon *daemon;
+	struct ecryptfs_daemon *daemon = file->private_data;
 	struct ecryptfs_msg_ctx *msg_ctx;
 	size_t packet_length_size;
-	char packet_length[3];
+	char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE];
 	size_t i;
 	size_t total_length;
-	uid_t euid = current_euid();
 	int rc;
 
-	mutex_lock(&ecryptfs_daemon_hash_mux);
-	/* TODO: Just use file->private_data? */
-	rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
-	BUG_ON(rc || !daemon);
 	mutex_lock(&daemon->mux);
 	if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
 		rc = 0;
-		mutex_unlock(&ecryptfs_daemon_hash_mux);
 		printk(KERN_WARNING "%s: Attempt to read from zombified "
 		       "daemon\n", __func__);
 		goto out_unlock_daemon;
 	}
 	if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) {
 		rc = 0;
-		mutex_unlock(&ecryptfs_daemon_hash_mux);
 		goto out_unlock_daemon;
 	}
 	/* This daemon will not go away so long as this flag is set */
 	daemon->flags |= ECRYPTFS_DAEMON_IN_READ;
-	mutex_unlock(&ecryptfs_daemon_hash_mux);
 check_list:
 	if (list_empty(&daemon->msg_ctx_out_queue)) {
 		mutex_unlock(&daemon->mux);
@@ -283,9 +269,6 @@ check_list:
 		 * message from the queue; try again */
 		goto check_list;
 	}
-	BUG_ON(euid != daemon->euid);
-	BUG_ON(current_user_ns() != daemon->user_ns);
-	BUG_ON(task_pid(current) != daemon->pid);
 	msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
 				   struct ecryptfs_msg_ctx, daemon_out_list);
 	BUG_ON(!msg_ctx);
@@ -304,15 +287,8 @@ check_list:
 		packet_length_size = 0;
 		msg_ctx->msg_size = 0;
 	}
-	/* miscdevfs packet format:
-	 *  Octet 0: Type
-	 *  Octets 1-4: network byte order msg_ctx->counter
-	 *  Octets 5-N0: Size of struct ecryptfs_message to follow
-	 *  Octets N0-N1: struct ecryptfs_message (including data)
-	 *
-	 *  Octets 5-N1 not written if the packet type does not
-	 *  include a message */
-	total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size);
+	total_length = (PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_length_size
+			+ msg_ctx->msg_size);
 	if (count < total_length) {
 		rc = 0;
 		printk(KERN_WARNING "%s: Only given user buffer of "
@@ -323,9 +299,10 @@ check_list:
 	rc = -EFAULT;
 	if (put_user(msg_ctx->type, buf))
 		goto out_unlock_msg_ctx;
-	if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1)))
+	if (put_user(cpu_to_be32(msg_ctx->counter),
+		     (__be32 __user *)(&buf[PKT_CTR_OFFSET])))
 		goto out_unlock_msg_ctx;
-	i = 5;
+	i = PKT_TYPE_SIZE + PKT_CTR_SIZE;
 	if (msg_ctx->msg) {
 		if (copy_to_user(&buf[i], packet_length, packet_length_size))
 			goto out_unlock_msg_ctx;
@@ -354,16 +331,12 @@ out_unlock_daemon:
  * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon
  * @data: Bytes comprising struct ecryptfs_message
  * @data_size: sizeof(struct ecryptfs_message) + data len
- * @euid: Effective user id of miscdevess sending the miscdev response
- * @user_ns: The namespace in which @euid applies
- * @pid: Miscdevess id of miscdevess sending the miscdev response
  * @seq: Sequence number for miscdev response packet
  *
  * Returns zero on success; non-zero otherwise
  */
-static int ecryptfs_miscdev_response(char *data, size_t data_size,
-				     uid_t euid, struct user_namespace *user_ns,
-				     struct pid *pid, u32 seq)
+static int ecryptfs_miscdev_response(struct ecryptfs_daemon *daemon, char *data,
+				     size_t data_size, u32 seq)
 {
 	struct ecryptfs_message *msg = (struct ecryptfs_message *)data;
 	int rc;
@@ -375,7 +348,7 @@ static int ecryptfs_miscdev_response(char *data, size_t data_size,
 		rc = -EINVAL;
 		goto out;
 	}
-	rc = ecryptfs_process_response(msg, euid, user_ns, pid, seq);
+	rc = ecryptfs_process_response(daemon, msg, seq);
 	if (rc)
 		printk(KERN_ERR
 		       "Error processing response message; rc = [%d]\n", rc);
@@ -385,17 +358,11 @@ out:
 
 /**
  * ecryptfs_miscdev_write - handle write to daemon miscdev handle
- * @file: File for misc dev handle (ignored)
+ * @file: File for misc dev handle
  * @buf: Buffer containing user data
  * @count: Amount of data in @buf
  * @ppos: Pointer to offset in file (ignored)
  *
- * miscdevfs packet format:
- *  Octet 0: Type
- *  Octets 1-4: network byte order msg_ctx->counter (0's for non-response)
- *  Octets 5-N0: Size of struct ecryptfs_message to follow
- *  Octets N0-N1: struct ecryptfs_message (including data)
- *
  * Returns the number of bytes read from @buf
  */
 static ssize_t
@@ -404,60 +371,76 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
 {
 	__be32 counter_nbo;
 	u32 seq;
-	size_t packet_size, packet_size_length, i;
-	ssize_t sz = 0;
+	size_t packet_size, packet_size_length;
 	char *data;
-	uid_t euid = current_euid();
-	int rc;
+	unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE];
+	ssize_t rc;
 
-	if (count == 0)
-		goto out;
+	if (count == 0) {
+		return 0;
+	} else if (count == MIN_NON_MSG_PKT_SIZE) {
+		/* Likely a harmless MSG_HELO or MSG_QUIT - no packet length */
+		goto memdup;
+	} else if (count < MIN_MSG_PKT_SIZE || count > MAX_MSG_PKT_SIZE) {
+		printk(KERN_WARNING "%s: Acceptable packet size range is "
+		       "[%d-%zu], but amount of data written is [%zu].",
+		       __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count);
+		return -EINVAL;
+	}
+
+	if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET],
+			   sizeof(packet_size_peek))) {
+		printk(KERN_WARNING "%s: Error while inspecting packet size\n",
+		       __func__);
+		return -EFAULT;
+	}
+
+	rc = ecryptfs_parse_packet_length(packet_size_peek, &packet_size,
+					  &packet_size_length);
+	if (rc) {
+		printk(KERN_WARNING "%s: Error parsing packet length; "
+		       "rc = [%zd]\n", __func__, rc);
+		return rc;
+	}
+
+	if ((PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_size_length + packet_size)
+	    != count) {
+		printk(KERN_WARNING "%s: Invalid packet size [%zu]\n", __func__,
+		       packet_size);
+		return -EINVAL;
+	}
 
+memdup:
 	data = memdup_user(buf, count);
 	if (IS_ERR(data)) {
 		printk(KERN_ERR "%s: memdup_user returned error [%ld]\n",
 		       __func__, PTR_ERR(data));
-		goto out;
+		return PTR_ERR(data);
 	}
-	sz = count;
-	i = 0;
-	switch (data[i++]) {
+	switch (data[PKT_TYPE_OFFSET]) {
 	case ECRYPTFS_MSG_RESPONSE:
-		if (count < (1 + 4 + 1 + sizeof(struct ecryptfs_message))) {
+		if (count < (MIN_MSG_PKT_SIZE
+			     + sizeof(struct ecryptfs_message))) {
 			printk(KERN_WARNING "%s: Minimum acceptable packet "
 			       "size is [%zd], but amount of data written is "
 			       "only [%zd]. Discarding response packet.\n",
 			       __func__,
-			       (1 + 4 + 1 + sizeof(struct ecryptfs_message)),
-			       count);
+			       (MIN_MSG_PKT_SIZE
+				+ sizeof(struct ecryptfs_message)), count);
+			rc = -EINVAL;
 			goto out_free;
 		}
-		memcpy(&counter_nbo, &data[i], 4);
+		memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE);
 		seq = be32_to_cpu(counter_nbo);
-		i += 4;
-		rc = ecryptfs_parse_packet_length(&data[i], &packet_size,
-						  &packet_size_length);
+		rc = ecryptfs_miscdev_response(file->private_data,
+				&data[PKT_LEN_OFFSET + packet_size_length],
+				packet_size, seq);
 		if (rc) {
-			printk(KERN_WARNING "%s: Error parsing packet length; "
-			       "rc = [%d]\n", __func__, rc);
-			goto out_free;
-		}
-		i += packet_size_length;
-		if ((1 + 4 + packet_size_length + packet_size) != count) {
-			printk(KERN_WARNING "%s: (1 + packet_size_length([%zd])"
-			       " + packet_size([%zd]))([%zd]) != "
-			       "count([%zd]). Invalid packet format.\n",
-			       __func__, packet_size_length, packet_size,
-			       (1 + packet_size_length + packet_size), count);
-			goto out_free;
-		}
-		rc = ecryptfs_miscdev_response(&data[i], packet_size,
-					       euid, current_user_ns(),
-					       task_pid(current), seq);
-		if (rc)
 			printk(KERN_WARNING "%s: Failed to deliver miscdev "
-			       "response to requesting operation; rc = [%d]\n",
+			       "response to requesting operation; rc = [%zd]\n",
 			       __func__, rc);
+			goto out_free;
+		}
 		break;
 	case ECRYPTFS_MSG_HELO:
 	case ECRYPTFS_MSG_QUIT:
@@ -466,21 +449,24 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
 		ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
 				"message of unrecognized type [%d]\n",
 				data[0]);
-		break;
+		rc = -EINVAL;
+		goto out_free;
 	}
+	rc = count;
 out_free:
 	kfree(data);
-out:
-	return sz;
+	return rc;
 }
 
 
 static const struct file_operations ecryptfs_miscdev_fops = {
+	.owner   = THIS_MODULE,
 	.open    = ecryptfs_miscdev_open,
 	.poll    = ecryptfs_miscdev_poll,
 	.read    = ecryptfs_miscdev_read,
 	.write   = ecryptfs_miscdev_write,
 	.release = ecryptfs_miscdev_release,
+	.llseek  = noop_llseek,
 };
 
 static struct miscdevice ecryptfs_miscdev = {
@@ -499,7 +485,7 @@ static struct miscdevice ecryptfs_miscdev = {
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_init_ecryptfs_miscdev(void)
+int __init ecryptfs_init_ecryptfs_miscdev(void)
 {
 	int rc;