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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /security/inode.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'security/inode.c')
-rw-r--r--security/inode.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/security/inode.c b/security/inode.c
new file mode 100644
index 000000000..080402367
--- /dev/null
+++ b/security/inode.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * inode.c - securityfs
+ *
+ * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ * Based on fs/debugfs/inode.c which had the following copyright notice:
+ * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2004 IBM Inc.
+ */
+
+/* #define DEBUG */
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+#include <linux/lsm_hooks.h>
+#include <linux/magic.h>
+
+#include "lsm.h"
+
+static struct vfsmount *mount;
+static int mount_count;
+
+static void securityfs_free_inode(struct inode *inode)
+{
+ if (S_ISLNK(inode->i_mode))
+ kfree_const(inode->i_link);
+ free_inode_nonrcu(inode);
+}
+
+static const struct super_operations securityfs_super_operations = {
+ .statfs = simple_statfs,
+ .free_inode = securityfs_free_inode,
+};
+
+static int securityfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+ static const struct tree_descr files[] = {{""}};
+ int error;
+
+ error = simple_fill_super(sb, SECURITYFS_MAGIC, files);
+ if (error)
+ return error;
+
+ sb->s_op = &securityfs_super_operations;
+
+ return 0;
+}
+
+static int securityfs_get_tree(struct fs_context *fc)
+{
+ return get_tree_single(fc, securityfs_fill_super);
+}
+
+static const struct fs_context_operations securityfs_context_ops = {
+ .get_tree = securityfs_get_tree,
+};
+
+static int securityfs_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &securityfs_context_ops;
+ return 0;
+}
+
+static struct file_system_type fs_type = {
+ .owner = THIS_MODULE,
+ .name = "securityfs",
+ .init_fs_context = securityfs_init_fs_context,
+ .kill_sb = kill_anon_super,
+};
+
+/**
+ * securityfs_create_dentry - create a dentry in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is %NULL, then the
+ * file will be created in the root of the securityfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ * @iops: a point to a struct of inode_operations that should be used for
+ * this file/dir
+ *
+ * This is the basic "create a file/dir/symlink" function for
+ * securityfs. It allows for a wide range of flexibility in creating
+ * a file, or a directory (if you want to create a directory, the
+ * securityfs_create_dir() function is recommended to be used
+ * instead).
+ *
+ * This function returns a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the securityfs_remove() function when the
+ * file is to be removed (no automatic cleanup happens if your module
+ * is unloaded, you are responsible here). If an error occurs, the
+ * function will return the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops,
+ const struct inode_operations *iops)
+{
+ struct dentry *dentry;
+ struct inode *dir, *inode;
+ int error;
+ bool pinned = false;
+
+ if (!(mode & S_IFMT))
+ mode = (mode & S_IALLUGO) | S_IFREG;
+
+ pr_debug("securityfs: creating file '%s'\n",name);
+
+ if (!parent) {
+ error = simple_pin_fs(&fs_type, &mount, &mount_count);
+ if (error)
+ return ERR_PTR(error);
+ pinned = true;
+ parent = mount->mnt_root;
+ }
+
+ inode = new_inode(parent->d_sb);
+ if (unlikely(!inode)) {
+ dentry = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ dir = d_inode(parent);
+
+ dentry = simple_start_creating(parent, name);
+ if (IS_ERR(dentry)) {
+ iput(inode);
+ goto out;
+ }
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ simple_inode_init_ts(inode);
+ inode->i_private = data;
+ if (S_ISDIR(mode)) {
+ inode->i_op = &simple_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inc_nlink(inode);
+ inc_nlink(dir);
+ } else if (S_ISLNK(mode)) {
+ inode->i_op = iops ? iops : &simple_symlink_inode_operations;
+ inode->i_link = data;
+ } else {
+ inode->i_fop = fops;
+ }
+ d_make_persistent(dentry, inode);
+ simple_done_creating(dentry);
+ return dentry; // borrowed
+
+out:
+ if (pinned)
+ simple_release_fs(&mount, &mount_count);
+ return dentry;
+}
+
+/**
+ * securityfs_create_file - create a file in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is %NULL, then the
+ * file will be created in the root of the securityfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ *
+ * This function creates a file in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here). If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops)
+{
+ return securityfs_create_dentry(name, mode, parent, data, fops, NULL);
+}
+EXPORT_SYMBOL_GPL(securityfs_create_file);
+
+/**
+ * securityfs_create_dir - create a directory in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the directory to
+ * create.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is %NULL, then the
+ * directory will be created in the root of the securityfs filesystem.
+ *
+ * This function creates a directory in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here). If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
+{
+ return securityfs_create_file(name, S_IFDIR | 0755, parent, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(securityfs_create_dir);
+
+/**
+ * securityfs_create_symlink - create a symlink in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the symlink to
+ * create.
+ * @parent: a pointer to the parent dentry for the symlink. This should be a
+ * directory dentry if set. If this parameter is %NULL, then the
+ * directory will be created in the root of the securityfs filesystem.
+ * @target: a pointer to a string containing the name of the symlink's target.
+ * If this parameter is %NULL, then the @iops parameter needs to be
+ * setup to handle .readlink and .get_link inode_operations.
+ * @iops: a pointer to the struct inode_operations to use for the symlink. If
+ * this parameter is %NULL, then the default simple_symlink_inode
+ * operations will be used.
+ *
+ * This function creates a symlink in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here). If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_symlink(const char *name,
+ struct dentry *parent,
+ const char *target,
+ const struct inode_operations *iops)
+{
+ struct dentry *dent;
+ const char *link = NULL;
+
+ if (target) {
+ link = kstrdup_const(target, GFP_KERNEL);
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ }
+ dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent,
+ (void *)link, NULL, iops);
+ if (IS_ERR(dent))
+ kfree_const(link);
+
+ return dent;
+}
+EXPORT_SYMBOL_GPL(securityfs_create_symlink);
+
+static void remove_one(struct dentry *victim)
+{
+ if (victim->d_parent == victim->d_sb->s_root)
+ simple_release_fs(&mount, &mount_count);
+}
+
+/**
+ * securityfs_remove - removes a file or directory from the securityfs filesystem
+ *
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
+ *
+ * This function removes a file or directory in securityfs that was previously
+ * created with a call to another securityfs function (like
+ * securityfs_create_file() or variants thereof.)
+ *
+ * This function is required to be called in order for the file to be
+ * removed. No automatic cleanup of files will happen when a module is
+ * removed; you are responsible here.
+ *
+ * AV: when applied to directory it will take all children out; no need to call
+ * it for descendents if ancestor is getting killed.
+ */
+void securityfs_remove(struct dentry *dentry)
+{
+ if (IS_ERR_OR_NULL(dentry))
+ return;
+
+ simple_pin_fs(&fs_type, &mount, &mount_count);
+ simple_recursive_removal(dentry, remove_one);
+ simple_release_fs(&mount, &mount_count);
+}
+EXPORT_SYMBOL_GPL(securityfs_remove);
+
+#ifdef CONFIG_SECURITY
+#include <linux/spinlock.h>
+
+static struct dentry *lsm_dentry;
+
+static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ int i;
+ static char *str;
+ static size_t len;
+ static DEFINE_SPINLOCK(lock);
+
+ /* NOTE: we never free or modify the string once it is set */
+
+ if (unlikely(!str || !len)) {
+ char *str_tmp;
+ size_t len_tmp = 0;
+
+ for (i = 0; i < lsm_active_cnt; i++)
+ /* the '+ 1' accounts for either a comma or a NUL */
+ len_tmp += strlen(lsm_idlist[i]->name) + 1;
+
+ str_tmp = kmalloc(len_tmp, GFP_KERNEL);
+ if (!str_tmp)
+ return -ENOMEM;
+ str_tmp[0] = '\0';
+
+ for (i = 0; i < lsm_active_cnt; i++) {
+ if (i > 0)
+ strcat(str_tmp, ",");
+ strcat(str_tmp, lsm_idlist[i]->name);
+ }
+
+ spin_lock(&lock);
+ if (!str) {
+ str = str_tmp;
+ len = len_tmp - 1;
+ } else
+ kfree(str_tmp);
+ spin_unlock(&lock);
+ }
+
+ return simple_read_from_buffer(buf, count, ppos, str, len);
+}
+
+static const struct file_operations lsm_ops = {
+ .read = lsm_read,
+ .llseek = generic_file_llseek,
+};
+#endif
+
+int __init securityfs_init(void)
+{
+ int retval;
+
+ retval = sysfs_create_mount_point(kernel_kobj, "security");
+ if (retval)
+ return retval;
+
+ retval = register_filesystem(&fs_type);
+ if (retval) {
+ sysfs_remove_mount_point(kernel_kobj, "security");
+ return retval;
+ }
+#ifdef CONFIG_SECURITY
+ lsm_dentry = securityfs_create_file("lsm", 0444, NULL, NULL,
+ &lsm_ops);
+#endif
+ return 0;
+}