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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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