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    Subject[PATCH 7/7] AppArmor: Add the ability to mediate mount
    Date
    Add the ability for apparmor to do mediation of mount operations. Mount
    rules require an updated apparmor_parser (2.8 series) for policy compilation.

    The basic form of the rules are.

    [audit] [deny] mount [conds]* [device] [ -> [conds] path],
    [audit] [deny] remount [conds]* [path],
    [audit] [deny] umount [conds]* [path],
    [audit] [deny] pivotroot [oldroot=<value>] <path>

    remount is just a short cut for mount options=remount

    where [conds] can be
    fstype=<expr>
    options=<expr>

    Example mount commands
    mount, # allow all mounts, but not umount or pivotroot

    mount fstype=procfs, # allow mounting procfs anywhere

    mount options=(bind, ro) /foo -> /bar, # readonly bind mount

    mount /dev/sda -> /mnt,

    mount /dev/sd** -> /mnt/**,

    mount fstype=overlayfs options=(rw,upperdir=/tmp/upper/,lowerdir=/) -> /mnt/

    umount,

    umount /m*,

    See the apparmor userspace for full documentation

    Signed-off-by: John Johansen <john.johansen@canonical.com>
    Acked-by: Kees Cook <kees@ubuntu.com>
    ---
    include/linux/lsm_audit.h | 7 +
    security/apparmor/Makefile | 3 +-
    security/apparmor/apparmorfs.c | 13 +
    security/apparmor/audit.c | 4 +
    security/apparmor/domain.c | 2 +-
    security/apparmor/include/apparmor.h | 3 +-
    security/apparmor/include/audit.h | 4 +
    security/apparmor/include/domain.h | 2 +
    security/apparmor/include/mount.h | 53 +++
    security/apparmor/lsm.c | 59 ++++
    security/apparmor/mount.c | 600 ++++++++++++++++++++++++++++++++++
    11 files changed, 746 insertions(+), 4 deletions(-)
    create mode 100644 security/apparmor/include/mount.h
    create mode 100644 security/apparmor/mount.c

    diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
    index 88e78de..7611a42 100644
    --- a/include/linux/lsm_audit.h
    +++ b/include/linux/lsm_audit.h
    @@ -119,6 +119,13 @@ struct common_audit_data {
    unsigned long max;
    } rlim;
    struct {
    + const char *src_name;
    + const char *type;
    + const char *trans;
    + const char *data;
    + unsigned long flags;
    + } mnt;
    + struct {
    const char *target;
    u32 request;
    u32 denied;
    diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
    index 86103ce..30cf9b2 100644
    --- a/security/apparmor/Makefile
    +++ b/security/apparmor/Makefile
    @@ -4,11 +4,10 @@ obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o

    apparmor-y := apparmorfs.o audit.o capability.o context.o ipc.o lib.o match.o \
    path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \
    - resource.o sid.o file.o
    + resource.o sid.o file.o mount.o

    clean-files := capability_names.h rlim_names.h

    -
    # Build a lower case string table of capability names
    # Transforms lines from
    # #define CAP_DAC_OVERRIDE 1
    diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
    index 16c15ec..f38a259 100644
    --- a/security/apparmor/apparmorfs.c
    +++ b/security/apparmor/apparmorfs.c
    @@ -198,9 +198,22 @@ static struct aa_fs_entry aa_fs_entry_domain[] = {
    { }
    };

    +static struct aa_fs_entry aa_fs_entry_mount[] = {
    + AA_FS_FILE_STRING("mask", "mount umount"),
    + { }
    +};
    +
    +static struct aa_fs_entry aa_fs_entry_namespaces[] = {
    + AA_FS_FILE_BOOLEAN("profile", 1),
    + AA_FS_FILE_BOOLEAN("pivot_root", 1),
    + { }
    +};
    +
    static struct aa_fs_entry aa_fs_entry_features[] = {
    AA_FS_DIR("domain", aa_fs_entry_domain),
    AA_FS_DIR("file", aa_fs_entry_file),
    + AA_FS_DIR("mount", aa_fs_entry_mount),
    + AA_FS_DIR("namespaces", aa_fs_entry_namespaces),
    AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK),
    AA_FS_DIR("rlimit", aa_fs_entry_rlimit),
    { }
    diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
    index 61344b5..d63cfb6 100644
    --- a/security/apparmor/audit.c
    +++ b/security/apparmor/audit.c
    @@ -44,6 +44,10 @@ const char *op_table[] = {
    "file_mmap",
    "file_mprotect",

    + "pivotroot",
    + "mount",
    + "umount",
    +
    "create",
    "post_create",
    "bind",
    diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
    index 7c69599..6fc18d1 100644
    --- a/security/apparmor/domain.c
    +++ b/security/apparmor/domain.c
    @@ -242,7 +242,7 @@ static const char *next_name(int xtype, const char *name)
    *
    * Returns: refcounted profile, or NULL on failure (MAYBE NULL)
    */
    -static struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex)
    +struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex)
    {
    struct aa_profile *new_profile = NULL;
    struct aa_namespace *ns = profile->ns;
    diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
    index 40aedd9..e243d96 100644
    --- a/security/apparmor/include/apparmor.h
    +++ b/security/apparmor/include/apparmor.h
    @@ -29,8 +29,9 @@
    #define AA_CLASS_NET 4
    #define AA_CLASS_RLIMITS 5
    #define AA_CLASS_DOMAIN 6
    +#define AA_CLASS_MOUNT 7

    -#define AA_CLASS_LAST AA_CLASS_DOMAIN
    +#define AA_CLASS_LAST AA_CLASS_MOUNT

    /* Control parameters settable through module/boot flags */
    extern enum audit_mode aa_g_audit;
    diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
    index 9317cd8..0e8689d 100644
    --- a/security/apparmor/include/audit.h
    +++ b/security/apparmor/include/audit.h
    @@ -73,6 +73,10 @@ enum aa_ops {
    OP_FMMAP,
    OP_FMPROT,

    + OP_PIVOTROOT,
    + OP_MOUNT,
    + OP_UMOUNT,
    +
    OP_CREATE,
    OP_POST_CREATE,
    OP_BIND,
    diff --git a/security/apparmor/include/domain.h b/security/apparmor/include/domain.h
    index de04464..a3f70c5 100644
    --- a/security/apparmor/include/domain.h
    +++ b/security/apparmor/include/domain.h
    @@ -23,6 +23,8 @@ struct aa_domain {
    char **table;
    };

    +struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex);
    +
    int apparmor_bprm_set_creds(struct linux_binprm *bprm);
    int apparmor_bprm_secureexec(struct linux_binprm *bprm);
    void apparmor_bprm_committing_creds(struct linux_binprm *bprm);
    diff --git a/security/apparmor/include/mount.h b/security/apparmor/include/mount.h
    new file mode 100644
    index 0000000..6f936bc
    --- /dev/null
    +++ b/security/apparmor/include/mount.h
    @@ -0,0 +1,53 @@
    +/*
    + * AppArmor security module
    + *
    + * This file contains AppArmor file mediation function definitions.
    + *
    + * Copyright 2012 Canonical Ltd.
    + *
    + * This program is free software; you can redistribute it and/or
    + * modify it under the terms of the GNU General Public License as
    + * published by the Free Software Foundation, version 2 of the
    + * License.
    + */
    +
    +#ifndef __AA_MOUNT_H
    +#define __AA_MOUNT_H
    +
    +#include <linux/fs.h>
    +#include <linux/path.h>
    +
    +#include "domain.h"
    +#include "policy.h"
    +
    +/* mount perms */
    +#define AA_MAY_PIVOTROOT 0x01
    +#define AA_MAY_MOUNT 0x02
    +#define AA_MAY_UMOUNT 0x04
    +
    +#define AA_MS_IGNORE_MASK (MS_KERNMOUNT | MS_NOSEC | MS_ACTIVE | MS_BORN)
    +
    +
    +int aa_remount(struct aa_profile *profile, struct path *path,
    + unsigned long flags, void *data);
    +
    +int aa_bind_mount(struct aa_profile *profile, struct path *path,
    + const char *old_name, unsigned long flags);
    +
    +
    +int aa_mount_change_type(struct aa_profile *profile, struct path *path,
    + unsigned long flags);
    +
    +int aa_move_mount(struct aa_profile *profile, struct path *path,
    + const char *old_name);
    +
    +int aa_new_mount(struct aa_profile *profile, const char *dev_name,
    + struct path *path, const char *type, unsigned long flags,
    + void *data);
    +
    +int aa_umount(struct aa_profile *profile, struct vfsmount *mnt, int flags);
    +
    +int aa_pivotroot(struct aa_profile *profile, struct path *old_path,
    + struct path *new_path);
    +
    +#endif /* __AA_MOUNT_H */
    diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
    index 97ce8fa..08e0fa5 100644
    --- a/security/apparmor/lsm.c
    +++ b/security/apparmor/lsm.c
    @@ -35,6 +35,7 @@
    #include "include/path.h"
    #include "include/policy.h"
    #include "include/procattr.h"
    +#include "include/mount.h"

    /* Flag indicating whether initialization completed */
    int apparmor_initialized __initdata;
    @@ -511,6 +512,60 @@ static int apparmor_file_mprotect(struct vm_area_struct *vma,
    !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
    }

    +static int apparmor_sb_mount(char *dev_name, struct path *path, char *type,
    + unsigned long flags, void *data)
    +{
    + struct aa_profile *profile;
    + int error = 0;
    +
    + /* Discard magic */
    + if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
    + flags &= ~MS_MGC_MSK;
    +
    + flags &= ~AA_MS_IGNORE_MASK;
    +
    + profile = __aa_current_profile();
    + if (!unconfined(profile)) {
    + if (flags & MS_REMOUNT)
    + error = aa_remount(profile, path, flags, data);
    + else if (flags & MS_BIND)
    + error = aa_bind_mount(profile, path, dev_name, flags);
    + else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
    + MS_UNBINDABLE))
    + error = aa_mount_change_type(profile, path, flags);
    + else if (flags & MS_MOVE)
    + error = aa_move_mount(profile, path, dev_name);
    + else
    + error = aa_new_mount(profile, dev_name, path, type,
    + flags, data);
    + }
    + return error;
    +}
    +
    +static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
    +{
    + struct aa_profile *profile;
    + int error = 0;
    +
    + profile = __aa_current_profile();
    + if (!unconfined(profile))
    + error = aa_umount(profile, mnt, flags);
    +
    + return error;
    +}
    +
    +static int apparmor_sb_pivotroot(struct path *old_path, struct path *new_path)
    +{
    + struct aa_profile *profile;
    + int error = 0;
    +
    + profile = __aa_current_profile();
    + if (!unconfined(profile))
    + error = aa_pivotroot(profile, old_path, new_path);
    +
    + return error;
    +}
    +
    static int apparmor_getprocattr(struct task_struct *task, char *name,
    char **value)
    {
    @@ -628,6 +683,10 @@ static struct security_operations apparmor_ops = {
    .capget = apparmor_capget,
    .capable = apparmor_capable,

    + .sb_mount = apparmor_sb_mount,
    + .sb_umount = apparmor_sb_umount,
    + .sb_pivotroot = apparmor_sb_pivotroot,
    +
    .path_link = apparmor_path_link,
    .path_unlink = apparmor_path_unlink,
    .path_symlink = apparmor_path_symlink,
    diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c
    new file mode 100644
    index 0000000..1352d60
    --- /dev/null
    +++ b/security/apparmor/mount.c
    @@ -0,0 +1,600 @@
    +/*
    + * AppArmor security module
    + *
    + * This file contains AppArmor mediation of files
    + *
    + * Copyright (C) 1998-2008 Novell/SUSE
    + * Copyright 2009-2012 Canonical Ltd.
    + *
    + * This program is free software; you can redistribute it and/or
    + * modify it under the terms of the GNU General Public License as
    + * published by the Free Software Foundation, version 2 of the
    + * License.
    + */
    +
    +#include <linux/fs.h>
    +#include <linux/mount.h>
    +#include <linux/namei.h>
    +
    +#include "include/apparmor.h"
    +#include "include/audit.h"
    +#include "include/context.h"
    +#include "include/domain.h"
    +#include "include/file.h"
    +#include "include/match.h"
    +#include "include/mount.h"
    +#include "include/path.h"
    +#include "include/policy.h"
    +
    +
    +static void audit_mnt_flags(struct audit_buffer *ab, unsigned long flags)
    +{
    + if (flags & MS_RDONLY)
    + audit_log_format(ab, "ro");
    + else
    + audit_log_format(ab, "rw");
    + if (flags & MS_NOSUID)
    + audit_log_format(ab, ", nosuid");
    + if (flags & MS_NODEV)
    + audit_log_format(ab, ", nodev");
    + if (flags & MS_NOEXEC)
    + audit_log_format(ab, ", noexec");
    + if (flags & MS_SYNCHRONOUS)
    + audit_log_format(ab, ", sync");
    + if (flags & MS_REMOUNT)
    + audit_log_format(ab, ", remount");
    + if (flags & MS_MANDLOCK)
    + audit_log_format(ab, ", mand");
    + if (flags & MS_DIRSYNC)
    + audit_log_format(ab, ", dirsync");
    + if (flags & MS_NOATIME)
    + audit_log_format(ab, ", noatime");
    + if (flags & MS_NODIRATIME)
    + audit_log_format(ab, ", nodiratime");
    + if (flags & MS_BIND)
    + audit_log_format(ab, flags & MS_REC ? ", rbind" : ", bind");
    + if (flags & MS_MOVE)
    + audit_log_format(ab, ", move");
    + if (flags & MS_SILENT)
    + audit_log_format(ab, ", silent");
    + if (flags & MS_POSIXACL)
    + audit_log_format(ab, ", acl");
    + if (flags & MS_UNBINDABLE)
    + audit_log_format(ab, flags & MS_REC ? ", runbindable" :
    + ", unbindable");
    + if (flags & MS_PRIVATE)
    + audit_log_format(ab, flags & MS_REC ? ", rprivate" :
    + ", private");
    + if (flags & MS_UNBINDABLE)
    + audit_log_format(ab, flags & MS_REC ? ", rslave" :
    + ", slave");
    + if (flags & MS_UNBINDABLE)
    + audit_log_format(ab, flags & MS_REC ? ", rshared" :
    + ", shared");
    + if (flags & MS_RELATIME)
    + audit_log_format(ab, ", relatime");
    + if (flags & MS_I_VERSION)
    + audit_log_format(ab, ", iversion");
    + if (flags & MS_STRICTATIME)
    + audit_log_format(ab, ", strictatime");
    + if (flags & MS_NOUSER)
    + audit_log_format(ab, ", nouser");
    +}
    +
    +/**
    + * mount_audit_cb - call back for mount specific audit fields
    + * @ab: audit_buffer (NOT NULL)
    + * @va: audit struct to audit values of (NOT NULL)
    + */
    +static void mount_audit_cb(struct audit_buffer *ab, void *va)
    +{
    + struct common_audit_data *sa = va;
    +
    + if (sa->aad.mnt.type) {
    + audit_log_format(ab, " fstype=");
    + audit_log_untrustedstring(ab, sa->aad.mnt.type);
    + }
    + if (sa->aad.mnt.src_name) {
    + audit_log_format(ab, " src_name=");
    + audit_log_untrustedstring(ab, sa->aad.mnt.src_name);
    + }
    + if (sa->aad.mnt.trans) {
    + audit_log_format(ab, " trans=");
    + audit_log_untrustedstring(ab, sa->aad.mnt.trans);
    + }
    + if (sa->aad.mnt.flags || sa->aad.op == OP_MOUNT) {
    + audit_log_format(ab, " flags=\"");
    + audit_mnt_flags(ab, sa->aad.mnt.flags);
    + audit_log_format(ab, "\"");
    + }
    + if (sa->aad.mnt.data) {
    + audit_log_format(ab, " options=");
    + audit_log_untrustedstring(ab, sa->aad.mnt.data);
    + }
    +}
    +
    +/**
    + * aa_audit_file - handle the auditing of file operations
    + * @profile: the profile being enforced (NOT NULL)
    + * @gfp: allocation flags
    + * @op: operation being mediated
    + * @name: name of object being mediated (MAYBE NULL)
    + * @src_name: src_name of object being mediated (MAYBE_NULL)
    + * @type: type of filesystem
    + * @trans: name of trans (MAYBE NULL)
    + * @flags: filesystem idependent mount flags
    + * @data: filesystem mount flags
    + * @request: permissions requested
    + * @perms: the permissions computed for the request (NOT NULL)
    + * @info: extra information message (MAYBE NULL)
    + * @error: 0 if operation allowed else failure error code
    + *
    + * Returns: %0 or error on failure
    + */
    +int aa_audit_mount(struct aa_profile *profile, gfp_t gfp, int op,
    + const char *name, const char *src_name, const char *type,
    + const char *trans, unsigned long flags, void *data,
    + u32 request, struct file_perms *perms, const char *info,
    + int error)
    +{
    + int audit_type = AUDIT_APPARMOR_AUTO;
    + struct common_audit_data sa;
    +
    + if (likely(!error)) {
    + u32 mask = perms->audit;
    +
    + if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL))
    + mask = 0xffff;
    +
    + /* mask off perms that are not being force audited */
    + request &= mask;
    +
    + if (likely(!request))
    + return 0;
    + audit_type = AUDIT_APPARMOR_AUDIT;
    + } else {
    + /* only report permissions that were denied */
    + request = request & ~perms->allow;
    +
    + if (request & perms->kill)
    + audit_type = AUDIT_APPARMOR_KILL;
    +
    + /* quiet known rejects, assumes quiet and kill do not overlap */
    + if ((request & perms->quiet) &&
    + AUDIT_MODE(profile) != AUDIT_NOQUIET &&
    + AUDIT_MODE(profile) != AUDIT_ALL)
    + request &= ~perms->quiet;
    +
    + if (!request)
    + return COMPLAIN_MODE(profile) ? 0 : error;
    + }
    +
    + COMMON_AUDIT_DATA_INIT(&sa, NONE);
    + sa.aad.op = op,
    + sa.aad.name = name;
    + sa.aad.info = info;
    + sa.aad.error = error;
    + sa.aad.mnt.src_name = src_name;
    + sa.aad.mnt.type = type;
    + sa.aad.mnt.trans = trans;
    + sa.aad.mnt.flags = flags;
    + sa.aad.mnt.data = data;
    +
    + return aa_audit(audit_type, profile, gfp, &sa, mount_audit_cb);
    +}
    +
    +
    +/**
    + * match_mnt_flags - Do an ordered match on mount flags
    + * @dfa: dfa to match against
    + * @state: state to start in
    + * @flags: mount flags to match against
    + *
    + * Mount flags are encoded as an ordered match. This is done instead of
    + * checking against a simple bitmask, to allow for logical operations
    + * on the flags.
    + *
    + * Returns: next state after flags match
    + */
    +static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state,
    + unsigned long flags)
    +{
    + unsigned int i;
    +
    + for (i = 0; i <= 31 ; ++i) {
    + if ((1 << i) & flags)
    + state = aa_dfa_next(dfa, state, i + 1);
    + }
    + return state;
    +}
    +
    +/**
    + * compute_mnt_perms - compute mount permission associated with @state
    + * @dfa: dfa to match against (NOT NULL)
    + * @state: state match finished in
    + *
    + * Returns: mount permissions
    + */
    +static struct file_perms compute_mnt_perms(struct aa_dfa *dfa,
    + unsigned int state)
    +{
    + struct file_perms perms;
    +
    + perms.kill = 0;
    + perms.allow = dfa_user_allow(dfa, state);
    + perms.audit = dfa_user_audit(dfa, state);
    + perms.quiet = dfa_user_quiet(dfa, state);
    + perms.xindex = dfa_user_xindex(dfa, state);
    +
    + return perms;
    +}
    +
    +static int path_flags(struct aa_profile *profile, struct path *path)
    +{
    + return profile->path_flags |
    + S_ISDIR(path->dentry->d_inode->i_mode) ? PATH_IS_DIR : 0;
    +}
    +
    +int aa_remount(struct aa_profile *profile, struct path *path,
    + unsigned long flags, void *data)
    +{
    + struct file_perms perms;
    + const char *name, *info = NULL;
    + char *buffer = NULL;
    + int binarydata, error;
    +
    + binarydata = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA;
    +
    + error = aa_path_name(path, path_flags(profile, path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip device */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip type */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = match_mnt_flags(profile->policy.dfa, state, flags);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + if (data && !binarydata)
    + state = aa_dfa_match(profile->policy.dfa, state,
    + data);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_MOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_MOUNT, name,
    + NULL, NULL, NULL, flags, data, AA_MAY_MOUNT,
    + &perms, info, error);
    + kfree(buffer);
    +
    + return error;
    +}
    +
    +int aa_bind_mount(struct aa_profile *profile, struct path *path,
    + const char *dev_name, unsigned long flags)
    +{
    + struct file_perms perms = { };
    + char *buffer = NULL, *old_buffer = NULL;
    + const char *name, *old_name, *info = NULL;
    + struct path old_path;
    + int error;
    +
    + if (!dev_name || !*dev_name)
    + return -EINVAL;
    +
    + flags &= MS_REC | MS_BIND;
    +
    + error = aa_path_name(path, path_flags(profile, path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
    + if (error)
    + goto audit;
    +
    + error = aa_path_name(&old_path, path_flags(profile, &old_path),
    + &old_buffer, &old_name, &info);
    + path_put(&old_path);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = aa_dfa_match(profile->policy.dfa, state, old_name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip type */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = match_mnt_flags(profile->policy.dfa, state, flags);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_MOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_MOUNT, name,
    + old_name, NULL, NULL, flags, NULL,
    + AA_MAY_MOUNT, &perms, info, error);
    +
    + kfree(buffer);
    + kfree(old_buffer);
    +
    + return error;
    +}
    +
    +int aa_mount_change_type(struct aa_profile *profile, struct path *path,
    + unsigned long flags)
    +{
    + struct file_perms perms = { };
    + char *buffer = NULL;
    + const char *name, *info = NULL;
    + int error;
    +
    + flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE |
    + MS_UNBINDABLE);
    +
    + error = aa_path_name(path, path_flags(profile, path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip device */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip type */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = match_mnt_flags(profile->policy.dfa, state, flags);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_MOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_MOUNT, name,
    + NULL, NULL, NULL, flags, NULL,
    + AA_MAY_MOUNT, &perms, info, error);
    + kfree(buffer);
    +
    + return error;
    +}
    +
    +int aa_move_mount(struct aa_profile *profile, struct path *path,
    + const char *orig_name)
    +{
    + struct file_perms perms = { };
    + char *buffer = NULL, *old_buffer = NULL;
    + const char *name, *old_name, *info = NULL;
    + struct path old_path;
    + int error;
    +
    + if (!orig_name || !*orig_name)
    + return -EINVAL;
    +
    + error = aa_path_name(path, path_flags(profile, path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path);
    + if (error)
    + goto audit;
    +
    + error = aa_path_name(&old_path, path_flags(profile, &old_path),
    + &old_buffer, &old_name, &info);
    + path_put(&old_path);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = aa_dfa_match(profile->policy.dfa, state, old_name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + /* skip type */
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = match_mnt_flags(profile->policy.dfa, state, MS_MOVE);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_MOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_MOUNT, name,
    + old_name, NULL, NULL, MS_MOVE, NULL,
    + AA_MAY_MOUNT, &perms, info, error);
    +
    + kfree(buffer);
    + kfree(old_buffer);
    +
    + return error;
    +}
    +
    +int aa_new_mount(struct aa_profile *profile, const char *orig_dev_name,
    + struct path *path, const char *type, unsigned long flags,
    + void *data)
    +{
    + struct file_system_type *fstype = NULL;
    + struct file_perms perms = { };
    + char *buffer = NULL, *dev_buffer = NULL;
    + const char *name, *dev_name, *info = NULL;
    + struct path dev_path;
    + int binary_data, error;
    +
    + fstype = get_fs_type(type);
    + if (!fstype) {
    + error = -ENODEV;
    + goto out;
    + }
    + binary_data = fstype->fs_flags & FS_BINARY_MOUNTDATA;
    +
    + if (fstype->fs_flags & FS_REQUIRES_DEV) {
    + if (!dev_name) {
    + error = -ENOENT;
    + goto out;
    + }
    +
    + error = kern_path(orig_dev_name, LOOKUP_FOLLOW, &dev_path);
    + if (error)
    + goto audit;
    +
    + error = aa_path_name(&dev_path, path_flags(profile, &dev_path),
    + &dev_buffer, &dev_name, &info);
    + path_put(&dev_path);
    + if (error)
    + goto audit;
    + } else
    + dev_name = orig_dev_name;
    +
    + error = aa_path_name(path, path_flags(profile, path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + if (dev_name)
    + state = aa_dfa_match(profile->policy.dfa, state,
    + dev_name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = aa_dfa_match(profile->policy.dfa, state, type);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = match_mnt_flags(profile->policy.dfa, state, flags);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + if (data && !binary_data)
    + state = aa_dfa_match(profile->policy.dfa, state,
    + data);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_MOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_MOUNT, name, dev_name,
    + type, NULL, flags, data, AA_MAY_MOUNT,
    + &perms, info, error);
    + kfree(buffer);
    + kfree(dev_buffer);
    +
    +out:
    + if (fstype)
    + put_filesystem(fstype);
    +
    + return error;
    +
    +}
    +
    +int aa_umount(struct aa_profile *profile, struct vfsmount *mnt, int flags)
    +{
    + struct file_perms perms = { };
    + char *buffer = NULL;
    + const char *name, *info = NULL;
    + int error;
    +
    + struct path path = { mnt, mnt->mnt_root };
    + error = aa_path_name(&path, path_flags(profile, &path), &buffer, &name,
    + &info);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + name);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_UMOUNT & ~perms.allow)
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_UMOUNT, name, NULL,
    + NULL, NULL, 0, NULL, AA_MAY_UMOUNT,
    + &perms, info, error);
    + kfree(buffer);
    +
    + return error;
    +}
    +
    +int aa_pivotroot(struct aa_profile *profile, struct path *old_path,
    + struct path *new_path)
    +{
    + struct file_perms perms = { };
    + struct aa_profile *target = NULL;
    + char *old_buffer = NULL, *new_buffer = NULL;
    + const char *old_name, *new_name, *info = NULL;
    + int error;
    +
    + error = aa_path_name(old_path, path_flags(profile, old_path),
    + &old_buffer, &old_name, &info);
    + if (error)
    + goto audit;
    +
    + error = aa_path_name(new_path, path_flags(profile, new_path),
    + &new_buffer, &new_name, &info);
    + if (error)
    + goto audit;
    +
    + if (profile->policy.dfa) {
    + unsigned int state;
    + state = aa_dfa_match(profile->policy.dfa,
    + profile->policy.start[AA_CLASS_MOUNT],
    + old_name);
    + state = aa_dfa_null_transition(profile->policy.dfa, state);
    + state = aa_dfa_match(profile->policy.dfa, state, new_name);
    + perms = compute_mnt_perms(profile->policy.dfa, state);
    + }
    +
    + if (AA_MAY_PIVOTROOT & perms.allow) {
    + if ((perms.xindex & AA_X_TYPE_MASK) == AA_X_TABLE) {
    + target = x_table_lookup(profile, perms.xindex);
    + if (!target)
    + error = -ENOENT;
    + else
    + error = aa_replace_current_profile(target);
    + }
    + } else
    + error = -EACCES;
    +
    +audit:
    + error = aa_audit_mount(profile, GFP_KERNEL, OP_PIVOTROOT, new_name,
    + old_name, NULL,
    + target ? target->base.name : NULL, 0, NULL,
    + AA_MAY_PIVOTROOT, &perms, info, error);
    +
    + aa_put_profile(target);
    + kfree(old_buffer);
    + kfree(new_buffer);
    +
    + return error;
    +}
    --
    1.7.9


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      Last update: 2012-02-27 23:27    [W:0.079 / U:3.252 seconds]
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