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Release 4.15 security/tomoyo/mount.c

Directory: security/tomoyo
// SPDX-License-Identifier: GPL-2.0
/*
 * security/tomoyo/mount.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include <linux/slab.h>
#include "common.h"

/* String table for special mount operations. */

static const char * const tomoyo_mounts[TOMOYO_MAX_SPECIAL_MOUNT] = {
	[TOMOYO_MOUNT_BIND]            = "--bind",
	[TOMOYO_MOUNT_MOVE]            = "--move",
	[TOMOYO_MOUNT_REMOUNT]         = "--remount",
	[TOMOYO_MOUNT_MAKE_UNBINDABLE] = "--make-unbindable",
	[TOMOYO_MOUNT_MAKE_PRIVATE]    = "--make-private",
	[TOMOYO_MOUNT_MAKE_SLAVE]      = "--make-slave",
	[TOMOYO_MOUNT_MAKE_SHARED]     = "--make-shared",
};

/**
 * tomoyo_audit_mount_log - Audit mount log.
 *
 * @r: Pointer to "struct tomoyo_request_info".
 *
 * Returns 0 on success, negative value otherwise.
 */

static int tomoyo_audit_mount_log(struct tomoyo_request_info *r) { return tomoyo_supervisor(r, "file mount %s %s %s 0x%lX\n", r->param.mount.dev->name, r->param.mount.dir->name, r->param.mount.type->name, r->param.mount.flags); }

Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa57100.00%3100.00%
Total57100.00%3100.00%

/** * tomoyo_check_mount_acl - Check permission for path path path number operation. * * @r: Pointer to "struct tomoyo_request_info". * @ptr: Pointer to "struct tomoyo_acl_info". * * Returns true if granted, false otherwise. */
static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r, const struct tomoyo_acl_info *ptr) { const struct tomoyo_mount_acl *acl = container_of(ptr, typeof(*acl), head); return tomoyo_compare_number_union(r->param.mount.flags, &acl->flags) && tomoyo_compare_name_union(r->param.mount.type, &acl->fs_type) && tomoyo_compare_name_union(r->param.mount.dir, &acl->dir_name) && (!r->param.mount.need_dev || tomoyo_compare_name_union(r->param.mount.dev, &acl->dev_name)); }

Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa112100.00%1100.00%
Total112100.00%1100.00%

/** * tomoyo_mount_acl - Check permission for mount() operation. * * @r: Pointer to "struct tomoyo_request_info". * @dev_name: Name of device file. Maybe NULL. * @dir: Pointer to "struct path". * @type: Name of filesystem type. * @flags: Mount options. * * Returns 0 on success, negative value otherwise. * * Caller holds tomoyo_read_lock(). */
static int tomoyo_mount_acl(struct tomoyo_request_info *r, const char *dev_name, const struct path *dir, const char *type, unsigned long flags) { struct tomoyo_obj_info obj = { }; struct path path; struct file_system_type *fstype = NULL; const char *requested_type = NULL; const char *requested_dir_name = NULL; const char *requested_dev_name = NULL; struct tomoyo_path_info rtype; struct tomoyo_path_info rdev; struct tomoyo_path_info rdir; int need_dev = 0; int error = -ENOMEM; r->obj = &obj; /* Get fstype. */ requested_type = tomoyo_encode(type); if (!requested_type) goto out; rtype.name = requested_type; tomoyo_fill_path_info(&rtype); /* Get mount point. */ obj.path2 = *dir; requested_dir_name = tomoyo_realpath_from_path(dir); if (!requested_dir_name) { error = -ENOMEM; goto out; } rdir.name = requested_dir_name; tomoyo_fill_path_info(&rdir); /* Compare fs name. */ if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]) { /* dev_name is ignored. */ } else if (type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE] || type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE] || type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE] || type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]) { /* dev_name is ignored. */ } else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND] || type == tomoyo_mounts[TOMOYO_MOUNT_MOVE]) { need_dev = -1; /* dev_name is a directory */ } else { fstype = get_fs_type(type); if (!fstype) { error = -ENODEV; goto out; } if (fstype->fs_flags & FS_REQUIRES_DEV) /* dev_name is a block device file. */ need_dev = 1; } if (need_dev) { /* Get mount point or device file. */ if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) { error = -ENOENT; goto out; } obj.path1 = path; requested_dev_name = tomoyo_realpath_from_path(&path); if (!requested_dev_name) { error = -ENOENT; goto out; } } else { /* Map dev_name to "<NULL>" if no dev_name given. */ if (!dev_name) dev_name = "<NULL>"; requested_dev_name = tomoyo_encode(dev_name); if (!requested_dev_name) { error = -ENOMEM; goto out; } } rdev.name = requested_dev_name; tomoyo_fill_path_info(&rdev); r->param_type = TOMOYO_TYPE_MOUNT_ACL; r->param.mount.need_dev = need_dev; r->param.mount.dev = &rdev; r->param.mount.dir = &rdir; r->param.mount.type = &rtype; r->param.mount.flags = flags; do { tomoyo_check_acl(r, tomoyo_check_mount_acl); error = tomoyo_audit_mount_log(r); } while (error == TOMOYO_RETRY_REQUEST); out: kfree(requested_dev_name); kfree(requested_dir_name); if (fstype) put_filesystem(fstype); kfree(requested_type); /* Drop refcount obtained by kern_path(). */ if (obj.path1.dentry) path_put(&obj.path1); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa51499.61%981.82%
Al Viro20.39%218.18%
Total516100.00%11100.00%

/** * tomoyo_mount_permission - Check permission for mount() operation. * * @dev_name: Name of device file. Maybe NULL. * @path: Pointer to "struct path". * @type: Name of filesystem type. Maybe NULL. * @flags: Mount options. * @data_page: Optional data. Maybe NULL. * * Returns 0 on success, negative value otherwise. */
int tomoyo_mount_permission(const char *dev_name, const struct path *path, const char *type, unsigned long flags, void *data_page) { struct tomoyo_request_info r; int error; int idx; if (tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_MOUNT) == TOMOYO_CONFIG_DISABLED) return 0; if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; if (flags & MS_REMOUNT) { type = tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]; flags &= ~MS_REMOUNT; } else if (flags & MS_BIND) { type = tomoyo_mounts[TOMOYO_MOUNT_BIND]; flags &= ~MS_BIND; } else if (flags & MS_SHARED) { if (flags & (MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) return -EINVAL; type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]; flags &= ~MS_SHARED; } else if (flags & MS_PRIVATE) { if (flags & (MS_SHARED | MS_SLAVE | MS_UNBINDABLE)) return -EINVAL; type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE]; flags &= ~MS_PRIVATE; } else if (flags & MS_SLAVE) { if (flags & (MS_SHARED | MS_PRIVATE | MS_UNBINDABLE)) return -EINVAL; type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE]; flags &= ~MS_SLAVE; } else if (flags & MS_UNBINDABLE) { if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE)) return -EINVAL; type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE]; flags &= ~MS_UNBINDABLE; } else if (flags & MS_MOVE) { type = tomoyo_mounts[TOMOYO_MOUNT_MOVE]; flags &= ~MS_MOVE; } if (!type) type = "<NULL>"; idx = tomoyo_read_lock(); error = tomoyo_mount_acl(&r, dev_name, path, type, flags); tomoyo_read_unlock(idx); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa31799.37%571.43%
Al Viro20.63%228.57%
Total319100.00%7100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Tetsuo Handa106699.53%1583.33%
Al Viro40.37%211.11%
Greg Kroah-Hartman10.09%15.56%
Total1071100.00%18100.00%
Directory: security/tomoyo
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