From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- fs/ecryptfs/miscdev.c | 499 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 499 insertions(+) create mode 100644 fs/ecryptfs/miscdev.c (limited to 'fs/ecryptfs/miscdev.c') diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c new file mode 100644 index 000000000..68804399a --- /dev/null +++ b/fs/ecryptfs/miscdev.c @@ -0,0 +1,499 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * eCryptfs: Linux filesystem encryption layer + * + * Copyright (C) 2008 International Business Machines Corp. + * Author(s): Michael A. Halcrow + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "ecryptfs_kernel.h" + +static atomic_t ecryptfs_num_miscdev_opens; + +/** + * ecryptfs_miscdev_poll + * @file: dev file + * @pt: dev poll table (ignored) + * + * Returns the poll mask + */ +static __poll_t +ecryptfs_miscdev_poll(struct file *file, poll_table *pt) +{ + struct ecryptfs_daemon *daemon = file->private_data; + __poll_t mask = 0; + + mutex_lock(&daemon->mux); + if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { + printk(KERN_WARNING "%s: Attempt to poll on zombified " + "daemon\n", __func__); + goto out_unlock_daemon; + } + if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) + goto out_unlock_daemon; + if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL) + goto out_unlock_daemon; + daemon->flags |= ECRYPTFS_DAEMON_IN_POLL; + mutex_unlock(&daemon->mux); + poll_wait(file, &daemon->wait, pt); + mutex_lock(&daemon->mux); + if (!list_empty(&daemon->msg_ctx_out_queue)) + mask |= EPOLLIN | EPOLLRDNORM; +out_unlock_daemon: + daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL; + mutex_unlock(&daemon->mux); + return mask; +} + +/** + * ecryptfs_miscdev_open + * @inode: inode of miscdev handle (ignored) + * @file: file for miscdev handle + * + * Returns zero on success; non-zero otherwise + */ +static int +ecryptfs_miscdev_open(struct inode *inode, struct file *file) +{ + struct ecryptfs_daemon *daemon = NULL; + int rc; + + mutex_lock(&ecryptfs_daemon_hash_mux); + rc = ecryptfs_find_daemon_by_euid(&daemon); + if (!rc) { + rc = -EINVAL; + goto out_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->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) { + rc = -EBUSY; + 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_unlock_daemon_list: + mutex_unlock(&ecryptfs_daemon_hash_mux); + return rc; +} + +/** + * ecryptfs_miscdev_release + * @inode: inode of 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. + * + * Returns zero on success; non-zero otherwise + */ +static int +ecryptfs_miscdev_release(struct inode *inode, struct file *file) +{ + struct ecryptfs_daemon *daemon = file->private_data; + int rc; + + mutex_lock(&daemon->mux); + 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(); + } + return rc; +} + +/** + * ecryptfs_send_miscdev + * @data: Data to send to daemon; may be NULL + * @data_size: Amount of data to send to daemon + * @msg_ctx: Message context, which is used to handle the reply. If + * this is NULL, then we do not expect a reply. + * @msg_type: Type of message + * @msg_flags: Flags for message + * @daemon: eCryptfs daemon object + * + * Add msg_ctx to queue and then, if it exists, notify the blocked + * miscdevess about the data being available. Must be called with + * ecryptfs_daemon_hash_mux held. + * + * Returns zero on success; non-zero otherwise + */ +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) +{ + struct ecryptfs_message *msg; + size_t msg_size; + + msg_size = struct_size(msg, data, data_size); + msg = kmalloc(msg_size, GFP_KERNEL); + if (!msg) + 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 = msg_size; + 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); + + 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: 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) + * + * Pulls the most recent message from the daemon queue, formats it for + * being sent via a miscdevfs handle, and copies it into @buf + * + * Returns the number of bytes copied into the user buffer + */ +static ssize_t +ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + struct ecryptfs_daemon *daemon = file->private_data; + struct ecryptfs_msg_ctx *msg_ctx; + size_t packet_length_size; + char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE]; + size_t i; + size_t total_length; + int rc; + + mutex_lock(&daemon->mux); + if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { + rc = 0; + 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; + goto out_unlock_daemon; + } + /* This daemon will not go away so long as this flag is set */ + daemon->flags |= ECRYPTFS_DAEMON_IN_READ; +check_list: + if (list_empty(&daemon->msg_ctx_out_queue)) { + mutex_unlock(&daemon->mux); + rc = wait_event_interruptible( + daemon->wait, !list_empty(&daemon->msg_ctx_out_queue)); + mutex_lock(&daemon->mux); + if (rc < 0) { + rc = 0; + goto out_unlock_daemon; + } + } + if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { + rc = 0; + goto out_unlock_daemon; + } + if (list_empty(&daemon->msg_ctx_out_queue)) { + /* Something else jumped in since the + * wait_event_interruptable() and removed the + * message from the queue; try again */ + goto check_list; + } + msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue, + struct ecryptfs_msg_ctx, daemon_out_list); + BUG_ON(!msg_ctx); + mutex_lock(&msg_ctx->mux); + if (msg_ctx->msg) { + rc = ecryptfs_write_packet_length(packet_length, + msg_ctx->msg_size, + &packet_length_size); + if (rc) { + rc = 0; + printk(KERN_WARNING "%s: Error writing packet length; " + "rc = [%d]\n", __func__, rc); + goto out_unlock_msg_ctx; + } + } else { + packet_length_size = 0; + msg_ctx->msg_size = 0; + } + 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 " + "size [%zd], but we need [%zd] to read the " + "pending message\n", __func__, count, total_length); + goto out_unlock_msg_ctx; + } + 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[PKT_CTR_OFFSET]))) + goto out_unlock_msg_ctx; + 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; + i += packet_length_size; + if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size)) + goto out_unlock_msg_ctx; + i += msg_ctx->msg_size; + } + rc = i; + list_del(&msg_ctx->daemon_out_list); + kfree(msg_ctx->msg); + msg_ctx->msg = NULL; + /* We do not expect a reply from the userspace daemon for any + * message type other than ECRYPTFS_MSG_REQUEST */ + if (msg_ctx->type != ECRYPTFS_MSG_REQUEST) + ecryptfs_msg_ctx_alloc_to_free(msg_ctx); +out_unlock_msg_ctx: + mutex_unlock(&msg_ctx->mux); +out_unlock_daemon: + daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ; + mutex_unlock(&daemon->mux); + return rc; +} + +/** + * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon + * @daemon: eCryptfs daemon object + * @data: Bytes comprising struct ecryptfs_message + * @data_size: sizeof(struct ecryptfs_message) + data len + * @seq: Sequence number for miscdev response packet + * + * Returns zero on success; non-zero otherwise + */ +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; + + if ((sizeof(*msg) + msg->data_len) != data_size) { + printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = " + "[%zd]; data_size = [%zd]. Invalid packet.\n", __func__, + (sizeof(*msg) + msg->data_len), data_size); + rc = -EINVAL; + goto out; + } + rc = ecryptfs_process_response(daemon, msg, seq); + if (rc) + printk(KERN_ERR + "Error processing response message; rc = [%d]\n", rc); +out: + return rc; +} + +/** + * ecryptfs_miscdev_write - handle write to daemon miscdev handle + * @file: File for misc dev handle + * @buf: Buffer containing user data + * @count: Amount of data in @buf + * @ppos: Pointer to offset in file (ignored) + * + * Returns the number of bytes read from @buf + */ +static ssize_t +ecryptfs_miscdev_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + __be32 counter_nbo; + u32 seq; + size_t packet_size, packet_size_length; + char *data; + unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE] = { }; + ssize_t rc; + + 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].\n", + __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count); + return -EINVAL; + } + + if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET], + min_t(size_t, count - 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)); + return PTR_ERR(data); + } + switch (data[PKT_TYPE_OFFSET]) { + case ECRYPTFS_MSG_RESPONSE: + 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__, + (MIN_MSG_PKT_SIZE + + sizeof(struct ecryptfs_message)), count); + rc = -EINVAL; + goto out_free; + } + memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE); + seq = be32_to_cpu(counter_nbo); + rc = ecryptfs_miscdev_response(file->private_data, + &data[PKT_LEN_OFFSET + packet_size_length], + packet_size, seq); + if (rc) { + printk(KERN_WARNING "%s: Failed to deliver miscdev " + "response to requesting operation; rc = [%zd]\n", + __func__, rc); + goto out_free; + } + break; + case ECRYPTFS_MSG_HELO: + case ECRYPTFS_MSG_QUIT: + break; + default: + ecryptfs_printk(KERN_WARNING, "Dropping miscdev " + "message of unrecognized type [%d]\n", + data[0]); + rc = -EINVAL; + goto out_free; + } + rc = count; +out_free: + kfree(data); + 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 = { + .minor = MISC_DYNAMIC_MINOR, + .name = "ecryptfs", + .fops = &ecryptfs_miscdev_fops +}; + +/** + * ecryptfs_init_ecryptfs_miscdev + * + * Messages sent to the userspace daemon from the kernel are placed on + * a queue associated with the daemon. The next read against the + * miscdev handle by that daemon will return the oldest message placed + * on the message queue for the daemon. + * + * Returns zero on success; non-zero otherwise + */ +int __init ecryptfs_init_ecryptfs_miscdev(void) +{ + int rc; + + atomic_set(&ecryptfs_num_miscdev_opens, 0); + rc = misc_register(&ecryptfs_miscdev); + if (rc) + printk(KERN_ERR "%s: Failed to register miscellaneous device " + "for communications with userspace daemons; rc = [%d]\n", + __func__, rc); + return rc; +} + +/** + * ecryptfs_destroy_ecryptfs_miscdev + * + * All of the daemons must be exorcised prior to calling this + * function. + */ +void ecryptfs_destroy_ecryptfs_miscdev(void) +{ + BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0); + misc_deregister(&ecryptfs_miscdev); +} -- cgit v1.3.1