Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

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

1 files changed, 514 insertions, 0 deletions

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
new file mode 100644
index 000000000..07a6c8448
--- /dev/null
+++ b/fs/ecryptfs/mmap.c
@@ -0,0 +1,514 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * eCryptfs: Linux filesystem encryption layer
+ * This is where eCryptfs coordinates the symmetric encryption and
+ * decryption of the file data as it passes between the lower
+ * encrypted file and the upper decrypted file.
+ *
+ * Copyright (C) 1997-2003 Erez Zadok
+ * Copyright (C) 2001-2003 Stony Brook University
+ * Copyright (C) 2004-2007 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ */
+
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/page-flags.h>
+#include <linux/mount.h>
+#include <linux/file.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/unaligned.h>
+#include "ecryptfs_kernel.h"
+
+/*
+ * This is where we encrypt the data and pass the encrypted data to
+ * the lower filesystem.  In OpenPGP-compatible mode, we operate on
+ * entire underlying packets.
+ */
+static int ecryptfs_writepages(struct address_space *mapping,
+		struct writeback_control *wbc)
+{
+	struct folio *folio = NULL;
+	int error;
+
+	while ((folio = writeback_iter(mapping, wbc, folio, &error))) {
+		error = ecryptfs_encrypt_page(folio);
+		if (error) {
+			ecryptfs_printk(KERN_WARNING,
+				"Error encrypting folio (index [0x%.16lx])\n",
+				folio->index);
+			folio_clear_uptodate(folio);
+			mapping_set_error(mapping, error);
+		}
+		folio_unlock(folio);
+	}
+
+	return error;
+}
+
+static void strip_xattr_flag(char *page_virt,
+			     struct ecryptfs_crypt_stat *crypt_stat)
+{
+	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+		size_t written;
+
+		crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;
+		ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat,
+						&written);
+		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+	}
+}
+
+/*
+ *   Header Extent:
+ *     Octets 0-7:        Unencrypted file size (big-endian)
+ *     Octets 8-15:       eCryptfs special marker
+ *     Octets 16-19:      Flags
+ *      Octet 16:         File format version number (between 0 and 255)
+ *      Octets 17-18:     Reserved
+ *      Octet 19:         Bit 1 (lsb): Reserved
+ *                        Bit 2: Encrypted?
+ *                        Bits 3-8: Reserved
+ *     Octets 20-23:      Header extent size (big-endian)
+ *     Octets 24-25:      Number of header extents at front of file
+ *                        (big-endian)
+ *     Octet  26:         Begin RFC 2440 authentication token packet set
+ */
+
+/**
+ * ecryptfs_copy_up_encrypted_with_header
+ * @folio: Sort of a ``virtual'' representation of the encrypted lower
+ *        file. The actual lower file does not have the metadata in
+ *        the header. This is locked.
+ * @crypt_stat: The eCryptfs inode's cryptographic context
+ *
+ * The ``view'' is the version of the file that userspace winds up
+ * seeing, with the header information inserted.
+ */
+static int
+ecryptfs_copy_up_encrypted_with_header(struct folio *folio,
+				       struct ecryptfs_crypt_stat *crypt_stat)
+{
+	loff_t extent_num_in_page = 0;
+	loff_t num_extents_per_page = (PAGE_SIZE
+				       / crypt_stat->extent_size);
+	int rc = 0;
+
+	while (extent_num_in_page < num_extents_per_page) {
+		loff_t view_extent_num = ((loff_t)folio->index
+					   * num_extents_per_page)
+					  + extent_num_in_page;
+		size_t num_header_extents_at_front =
+			(crypt_stat->metadata_size / crypt_stat->extent_size);
+
+		if (view_extent_num < num_header_extents_at_front) {
+			/* This is a header extent */
+			char *page_virt;
+
+			page_virt = kmap_local_folio(folio, 0);
+			memset(page_virt, 0, PAGE_SIZE);
+			/* TODO: Support more than one header extent */
+			if (view_extent_num == 0) {
+				size_t written;
+
+				rc = ecryptfs_read_xattr_region(
+					page_virt, folio->mapping->host);
+				strip_xattr_flag(page_virt + 16, crypt_stat);
+				ecryptfs_write_header_metadata(page_virt + 20,
+							       crypt_stat,
+							       &written);
+			}
+			kunmap_local(page_virt);
+			flush_dcache_folio(folio);
+			if (rc) {
+				printk(KERN_ERR "%s: Error reading xattr "
+				       "region; rc = [%d]\n", __func__, rc);
+				goto out;
+			}
+		} else {
+			/* This is an encrypted data extent */
+			loff_t lower_offset =
+				((view_extent_num * crypt_stat->extent_size)
+				 - crypt_stat->metadata_size);
+
+			rc = ecryptfs_read_lower_page_segment(
+				folio, (lower_offset >> PAGE_SHIFT),
+				(lower_offset & ~PAGE_MASK),
+				crypt_stat->extent_size, folio->mapping->host);
+			if (rc) {
+				printk(KERN_ERR "%s: Error attempting to read "
+				       "extent at offset [%lld] in the lower "
+				       "file; rc = [%d]\n", __func__,
+				       lower_offset, rc);
+				goto out;
+			}
+		}
+		extent_num_in_page++;
+	}
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_read_folio
+ * @file: An eCryptfs file
+ * @folio: Folio from eCryptfs inode mapping into which to stick the read data
+ *
+ * Read in a folio, decrypting if necessary.
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int ecryptfs_read_folio(struct file *file, struct folio *folio)
+{
+	struct inode *inode = folio->mapping->host;
+	struct ecryptfs_crypt_stat *crypt_stat =
+		&ecryptfs_inode_to_private(inode)->crypt_stat;
+	int err = 0;
+
+	if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+		err = ecryptfs_read_lower_page_segment(folio, folio->index, 0,
+				folio_size(folio), inode);
+	} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
+		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+			err = ecryptfs_copy_up_encrypted_with_header(folio,
+					crypt_stat);
+			if (err) {
+				printk(KERN_ERR "%s: Error attempting to copy "
+				       "the encrypted content from the lower "
+				       "file whilst inserting the metadata "
+				       "from the xattr into the header; err = "
+				       "[%d]\n", __func__, err);
+				goto out;
+			}
+
+		} else {
+			err = ecryptfs_read_lower_page_segment(folio,
+					folio->index, 0, folio_size(folio),
+					inode);
+			if (err) {
+				printk(KERN_ERR "Error reading page; err = "
+				       "[%d]\n", err);
+				goto out;
+			}
+		}
+	} else {
+		err = ecryptfs_decrypt_page(folio);
+		if (err) {
+			ecryptfs_printk(KERN_ERR, "Error decrypting page; "
+					"err = [%d]\n", err);
+			goto out;
+		}
+	}
+out:
+	ecryptfs_printk(KERN_DEBUG, "Unlocking folio with index = [0x%.16lx]\n",
+			folio->index);
+	folio_end_read(folio, err == 0);
+	return err;
+}
+
+/*
+ * Called with lower inode mutex held.
+ */
+static int fill_zeros_to_end_of_page(struct folio *folio, unsigned int to)
+{
+	struct inode *inode = folio->mapping->host;
+	int end_byte_in_page;
+
+	if ((i_size_read(inode) / PAGE_SIZE) != folio->index)
+		goto out;
+	end_byte_in_page = i_size_read(inode) % PAGE_SIZE;
+	if (to > end_byte_in_page)
+		end_byte_in_page = to;
+	folio_zero_segment(folio, end_byte_in_page, PAGE_SIZE);
+out:
+	return 0;
+}
+
+/**
+ * ecryptfs_write_begin
+ * @iocb: I/O control block for the eCryptfs file
+ * @mapping: The eCryptfs object
+ * @pos: The file offset at which to start writing
+ * @len: Length of the write
+ * @foliop: Pointer to return the folio
+ * @fsdata: Pointer to return fs data (unused)
+ *
+ * This function must zero any hole we create
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_write_begin(const struct kiocb *iocb,
+			struct address_space *mapping,
+			loff_t pos, unsigned len,
+			struct folio **foliop, void **fsdata)
+{
+	pgoff_t index = pos >> PAGE_SHIFT;
+	struct folio *folio;
+	loff_t prev_page_end_size;
+	int rc = 0;
+
+	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
+			mapping_gfp_mask(mapping));
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
+	*foliop = folio;
+
+	prev_page_end_size = ((loff_t)index << PAGE_SHIFT);
+	if (!folio_test_uptodate(folio)) {
+		struct ecryptfs_crypt_stat *crypt_stat =
+			&ecryptfs_inode_to_private(mapping->host)->crypt_stat;
+
+		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+			rc = ecryptfs_read_lower_page_segment(
+				folio, index, 0, PAGE_SIZE, mapping->host);
+			if (rc) {
+				printk(KERN_ERR "%s: Error attempting to read "
+				       "lower page segment; rc = [%d]\n",
+				       __func__, rc);
+				folio_clear_uptodate(folio);
+				goto out;
+			} else
+				folio_mark_uptodate(folio);
+		} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
+			if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+				rc = ecryptfs_copy_up_encrypted_with_header(
+					folio, crypt_stat);
+				if (rc) {
+					printk(KERN_ERR "%s: Error attempting "
+					       "to copy the encrypted content "
+					       "from the lower file whilst "
+					       "inserting the metadata from "
+					       "the xattr into the header; rc "
+					       "= [%d]\n", __func__, rc);
+					folio_clear_uptodate(folio);
+					goto out;
+				}
+				folio_mark_uptodate(folio);
+			} else {
+				rc = ecryptfs_read_lower_page_segment(
+					folio, index, 0, PAGE_SIZE,
+					mapping->host);
+				if (rc) {
+					printk(KERN_ERR "%s: Error reading "
+					       "page; rc = [%d]\n",
+					       __func__, rc);
+					folio_clear_uptodate(folio);
+					goto out;
+				}
+				folio_mark_uptodate(folio);
+			}
+		} else {
+			if (prev_page_end_size
+			    >= i_size_read(mapping->host)) {
+				folio_zero_range(folio, 0, PAGE_SIZE);
+				folio_mark_uptodate(folio);
+			} else if (len < PAGE_SIZE) {
+				rc = ecryptfs_decrypt_page(folio);
+				if (rc) {
+					printk(KERN_ERR "%s: Error decrypting "
+					       "page at index [%ld]; "
+					       "rc = [%d]\n",
+					       __func__, folio->index, rc);
+					folio_clear_uptodate(folio);
+					goto out;
+				}
+				folio_mark_uptodate(folio);
+			}
+		}
+	}
+	/* If creating a page or more of holes, zero them out via truncate.
+	 * Note, this will increase i_size. */
+	if (index != 0) {
+		if (prev_page_end_size > i_size_read(mapping->host)) {
+			rc = ecryptfs_truncate(iocb->ki_filp->f_path.dentry,
+					       prev_page_end_size);
+			if (rc) {
+				printk(KERN_ERR "%s: Error on attempt to "
+				       "truncate to (higher) offset [%lld];"
+				       " rc = [%d]\n", __func__,
+				       prev_page_end_size, rc);
+				goto out;
+			}
+		}
+	}
+	/* Writing to a new page, and creating a small hole from start
+	 * of page?  Zero it out. */
+	if ((i_size_read(mapping->host) == prev_page_end_size)
+	    && (pos != 0))
+		folio_zero_range(folio, 0, PAGE_SIZE);
+out:
+	if (unlikely(rc)) {
+		folio_unlock(folio);
+		folio_put(folio);
+	}
+	return rc;
+}
+
+/*
+ * ecryptfs_write_inode_size_to_header
+ *
+ * Writes the lower file size to the first 8 bytes of the header.
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
+{
+	__be64 file_size;
+	int rc;
+
+	file_size = cpu_to_be64(i_size_read(ecryptfs_inode));
+	rc = ecryptfs_write_lower(ecryptfs_inode, (char *)&file_size, 0,
+				  sizeof(file_size));
+	if (rc < 0)
+		printk(KERN_ERR "%s: Error writing file size to header; "
+		       "rc = [%d]\n", __func__, rc);
+	else
+		rc = 0;
+	return rc;
+}
+
+struct kmem_cache *ecryptfs_xattr_cache;
+
+static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
+{
+	ssize_t size;
+	void *xattr_virt;
+	struct dentry *lower_dentry =
+		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_path.dentry;
+	struct inode *lower_inode = d_inode(lower_dentry);
+	int rc;
+
+	if (!(lower_inode->i_opflags & IOP_XATTR)) {
+		printk(KERN_WARNING
+		       "No support for setting xattr in lower filesystem\n");
+		rc = -ENOSYS;
+		goto out;
+	}
+	xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL);
+	if (!xattr_virt) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	inode_lock(lower_inode);
+	size = __vfs_getxattr(lower_dentry, lower_inode, ECRYPTFS_XATTR_NAME,
+			      xattr_virt, PAGE_SIZE);
+	if (size < 0)
+		size = 8;
+	put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
+	rc = __vfs_setxattr(&nop_mnt_idmap, lower_dentry, lower_inode,
+			    ECRYPTFS_XATTR_NAME, xattr_virt, size, 0);
+	inode_unlock(lower_inode);
+	if (rc)
+		printk(KERN_ERR "Error whilst attempting to write inode size "
+		       "to lower file xattr; rc = [%d]\n", rc);
+	kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
+out:
+	return rc;
+}
+
+int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
+{
+	struct ecryptfs_crypt_stat *crypt_stat;
+
+	crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+	BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
+	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+		return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode);
+	else
+		return ecryptfs_write_inode_size_to_header(ecryptfs_inode);
+}
+
+/**
+ * ecryptfs_write_end
+ * @iocb: I/O control block for the eCryptfs file
+ * @mapping: The eCryptfs object
+ * @pos: The file position
+ * @len: The length of the data (unused)
+ * @copied: The amount of data copied
+ * @folio: The eCryptfs folio
+ * @fsdata: The fsdata (unused)
+ */
+static int ecryptfs_write_end(const struct kiocb *iocb,
+			struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct folio *folio, void *fsdata)
+{
+	pgoff_t index = pos >> PAGE_SHIFT;
+	unsigned from = pos & (PAGE_SIZE - 1);
+	unsigned to = from + copied;
+	struct inode *ecryptfs_inode = mapping->host;
+	struct ecryptfs_crypt_stat *crypt_stat =
+		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+	int rc;
+
+	ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
+			"(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
+	if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+		rc = ecryptfs_write_lower_page_segment(ecryptfs_inode,
+				folio, 0, to);
+		if (!rc) {
+			rc = copied;
+			fsstack_copy_inode_size(ecryptfs_inode,
+				ecryptfs_inode_to_lower(ecryptfs_inode));
+		}
+		goto out;
+	}
+	if (!folio_test_uptodate(folio)) {
+		if (copied < PAGE_SIZE) {
+			rc = 0;
+			goto out;
+		}
+		folio_mark_uptodate(folio);
+	}
+	/* Fills in zeros if 'to' goes beyond inode size */
+	rc = fill_zeros_to_end_of_page(folio, to);
+	if (rc) {
+		ecryptfs_printk(KERN_WARNING, "Error attempting to fill "
+			"zeros in page with index = [0x%.16lx]\n", index);
+		goto out;
+	}
+	rc = ecryptfs_encrypt_page(folio);
+	if (rc) {
+		ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
+				"index [0x%.16lx])\n", index);
+		goto out;
+	}
+	if (pos + copied > i_size_read(ecryptfs_inode)) {
+		i_size_write(ecryptfs_inode, pos + copied);
+		ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
+			"[0x%.16llx]\n",
+			(unsigned long long)i_size_read(ecryptfs_inode));
+	}
+	rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
+	if (rc)
+		printk(KERN_ERR "Error writing inode size to metadata; "
+		       "rc = [%d]\n", rc);
+	else
+		rc = copied;
+out:
+	folio_unlock(folio);
+	folio_put(folio);
+	return rc;
+}
+
+static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
+	int ret = bmap(lower_inode, &block);
+
+	if (ret)
+		return 0;
+	return block;
+}
+
+const struct address_space_operations ecryptfs_aops = {
+	.dirty_folio	= filemap_dirty_folio,
+	.writepages = ecryptfs_writepages,
+	.read_folio = ecryptfs_read_folio,
+	.write_begin = ecryptfs_write_begin,
+	.write_end = ecryptfs_write_end,
+	.migrate_folio = filemap_migrate_folio,
+	.bmap = ecryptfs_bmap,
+};