mirror of
https://gitlab.com/apparmor/apparmor.git
synced 2025-03-04 08:24:42 +01:00
1493 lines
40 KiB
Diff
1493 lines
40 KiB
Diff
From: John Johansen <jjohansen@suse.de>
|
|
Subject: AppArmor: Main Part
|
|
|
|
The underlying functions by which the AppArmor LSM hooks are implemented.
|
|
|
|
Signed-off-by: John Johansen <jjohansen@suse.de>
|
|
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
|
|
|
|
---
|
|
security/apparmor/main.c | 1478 +++++++++++++++++++++++++++++++++++++++++++++++
|
|
1 file changed, 1478 insertions(+)
|
|
|
|
--- /dev/null
|
|
+++ b/security/apparmor/main.c
|
|
@@ -0,0 +1,1478 @@
|
|
+/*
|
|
+ * Copyright (C) 2002-2007 Novell/SUSE
|
|
+ *
|
|
+ * 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.
|
|
+ *
|
|
+ * AppArmor Core
|
|
+ */
|
|
+
|
|
+#include <linux/security.h>
|
|
+#include <linux/namei.h>
|
|
+#include <linux/audit.h>
|
|
+#include <linux/mount.h>
|
|
+#include <linux/ptrace.h>
|
|
+
|
|
+#include "apparmor.h"
|
|
+
|
|
+#include "inline.h"
|
|
+
|
|
+/*
|
|
+ * Table of capability names: we generate it from capabilities.h.
|
|
+ */
|
|
+static const char *capability_names[] = {
|
|
+#include "capability_names.h"
|
|
+};
|
|
+
|
|
+struct aa_namespace *default_namespace;
|
|
+
|
|
+static int aa_inode_mode(struct inode *inode)
|
|
+{
|
|
+ /* if the inode doesn't exist the user is creating it */
|
|
+ if (!inode || current->fsuid == inode->i_uid)
|
|
+ return AA_USER_SHIFT;
|
|
+ return AA_OTHER_SHIFT;
|
|
+}
|
|
+
|
|
+int alloc_default_namespace(void)
|
|
+{
|
|
+ struct aa_namespace *ns;
|
|
+ char *name = kstrdup("default", GFP_KERNEL);
|
|
+ if (!name)
|
|
+ return -ENOMEM;
|
|
+ ns = alloc_aa_namespace(name);
|
|
+ if (!ns) {
|
|
+ kfree(name);
|
|
+ return -ENOMEM;
|
|
+ }
|
|
+
|
|
+ write_lock(&profile_ns_list_lock);
|
|
+ default_namespace = ns;
|
|
+ aa_get_namespace(ns);
|
|
+ list_add(&ns->list, &profile_ns_list);
|
|
+ write_unlock(&profile_ns_list_lock);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+void free_default_namespace(void)
|
|
+{
|
|
+ write_lock(&profile_ns_list_lock);
|
|
+ list_del_init(&default_namespace->list);
|
|
+ write_unlock(&profile_ns_list_lock);
|
|
+ aa_put_namespace(default_namespace);
|
|
+ default_namespace = NULL;
|
|
+}
|
|
+
|
|
+static void aa_audit_file_sub_mask(struct audit_buffer *ab, char *buffer,
|
|
+ int mask)
|
|
+{
|
|
+ const char unsafex[] = "upcn";
|
|
+ const char safex[] = "UPCN";
|
|
+ char *m = buffer;
|
|
+
|
|
+ if (mask & AA_EXEC_MMAP)
|
|
+ *m++ = 'm';
|
|
+ if (mask & MAY_READ)
|
|
+ *m++ = 'r';
|
|
+ if (mask & MAY_WRITE)
|
|
+ *m++ = 'w';
|
|
+ else if (mask & MAY_APPEND)
|
|
+ *m++ = 'a';
|
|
+ if (mask & MAY_EXEC) {
|
|
+ int index = AA_EXEC_INDEX(mask);
|
|
+ /* all indexes > 4 are also named transitions */
|
|
+ if (index > 4)
|
|
+ index = 4;
|
|
+ if (index > 0) {
|
|
+ if (mask & AA_EXEC_UNSAFE)
|
|
+ *m++ = unsafex[index - 1];
|
|
+ else
|
|
+ *m++ = safex[index - 1];
|
|
+ }
|
|
+ if (mask & AA_EXEC_INHERIT)
|
|
+ *m++ = 'i';
|
|
+ *m++ = 'x';
|
|
+ }
|
|
+ if (mask & AA_MAY_LINK)
|
|
+ *m++ = 'l';
|
|
+ if (mask & AA_MAY_LOCK)
|
|
+ *m++ = 'k';
|
|
+ *m++ = '\0';
|
|
+}
|
|
+
|
|
+static void aa_audit_file_mask(struct audit_buffer *ab, const char *name,
|
|
+ int mask)
|
|
+{
|
|
+ char user[10], other[10];
|
|
+
|
|
+ aa_audit_file_sub_mask(ab, user,
|
|
+ (mask & AA_USER_PERMS) >> AA_USER_SHIFT);
|
|
+ aa_audit_file_sub_mask(ab, other,
|
|
+ (mask & AA_OTHER_PERMS) >> AA_OTHER_SHIFT);
|
|
+
|
|
+ audit_log_format(ab, " %s=\"%s::%s\"", name, user, other);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_audit - Log an audit event to the audit subsystem
|
|
+ * @profile: profile to check against
|
|
+ * @sa: audit event
|
|
+ * @audit_cxt: audit context to log message to
|
|
+ * @type: audit event number
|
|
+ */
|
|
+static int aa_audit_base(struct aa_profile *profile, struct aa_audit *sa,
|
|
+ struct audit_context *audit_cxt, int type)
|
|
+{
|
|
+ struct audit_buffer *ab = NULL;
|
|
+
|
|
+ ab = audit_log_start(audit_cxt, sa->gfp_mask, type);
|
|
+
|
|
+ if (!ab) {
|
|
+ AA_ERROR("Unable to log event (%d) to audit subsys\n",
|
|
+ type);
|
|
+ /* don't fail operations in complain mode even if logging
|
|
+ * fails */
|
|
+ return type == AUDIT_APPARMOR_ALLOWED ? 0 : -ENOMEM;
|
|
+ }
|
|
+
|
|
+ if (sa->operation)
|
|
+ audit_log_format(ab, "operation=\"%s\"", sa->operation);
|
|
+
|
|
+ if (sa->info) {
|
|
+ audit_log_format(ab, " info=\"%s\"", sa->info);
|
|
+ if (sa->error_code)
|
|
+ audit_log_format(ab, " error=%d", sa->error_code);
|
|
+ }
|
|
+
|
|
+ if (sa->request_mask)
|
|
+ aa_audit_file_mask(ab, "requested_mask", sa->request_mask);
|
|
+
|
|
+ if (sa->denied_mask)
|
|
+ aa_audit_file_mask(ab, "denied_mask", sa->denied_mask);
|
|
+
|
|
+ if (sa->request_mask)
|
|
+ audit_log_format(ab, " fsuid=%d", current->fsuid);
|
|
+
|
|
+ if (sa->iattr) {
|
|
+ struct iattr *iattr = sa->iattr;
|
|
+
|
|
+ audit_log_format(ab, " attribute=\"%s%s%s%s%s%s%s\"",
|
|
+ iattr->ia_valid & ATTR_MODE ? "mode," : "",
|
|
+ iattr->ia_valid & ATTR_UID ? "uid," : "",
|
|
+ iattr->ia_valid & ATTR_GID ? "gid," : "",
|
|
+ iattr->ia_valid & ATTR_SIZE ? "size," : "",
|
|
+ iattr->ia_valid & (ATTR_ATIME | ATTR_ATIME_SET) ?
|
|
+ "atime," : "",
|
|
+ iattr->ia_valid & (ATTR_MTIME | ATTR_MTIME_SET) ?
|
|
+ "mtime," : "",
|
|
+ iattr->ia_valid & ATTR_CTIME ? "ctime," : "");
|
|
+ }
|
|
+
|
|
+ if (sa->task)
|
|
+ audit_log_format(ab, " task=%d", sa->task);
|
|
+
|
|
+ if (sa->parent)
|
|
+ audit_log_format(ab, " parent=%d", sa->parent);
|
|
+
|
|
+ if (sa->name) {
|
|
+ audit_log_format(ab, " name=");
|
|
+ audit_log_untrustedstring(ab, sa->name);
|
|
+ }
|
|
+
|
|
+ if (sa->name2) {
|
|
+ audit_log_format(ab, " name2=");
|
|
+ audit_log_untrustedstring(ab, sa->name2);
|
|
+ }
|
|
+
|
|
+ audit_log_format(ab, " pid=%d", current->pid);
|
|
+
|
|
+ if (profile) {
|
|
+ audit_log_format(ab, " profile=");
|
|
+ audit_log_untrustedstring(ab, profile->name);
|
|
+
|
|
+ if (profile->ns != default_namespace) {
|
|
+ audit_log_format(ab, " namespace=");
|
|
+ audit_log_untrustedstring(ab, profile->ns->name);
|
|
+ }
|
|
+ }
|
|
+
|
|
+ audit_log_end(ab);
|
|
+
|
|
+ return type == AUDIT_APPARMOR_ALLOWED ? 0 : sa->error_code;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_audit_syscallreject - Log a syscall rejection to the audit subsystem
|
|
+ * @profile: profile to check against
|
|
+ * @gfp: memory allocation flags
|
|
+ * @msg: string describing syscall being rejected
|
|
+ */
|
|
+int aa_audit_syscallreject(struct aa_profile *profile, gfp_t gfp,
|
|
+ const char *msg)
|
|
+{
|
|
+ struct aa_audit sa;
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "syscall";
|
|
+ sa.name = msg;
|
|
+ sa.gfp_mask = gfp;
|
|
+ sa.error_code = -EPERM;
|
|
+
|
|
+ return aa_audit_base(profile, &sa, current->audit_context,
|
|
+ AUDIT_APPARMOR_DENIED);
|
|
+}
|
|
+
|
|
+int aa_audit_message(struct aa_profile *profile, struct aa_audit *sa,
|
|
+ int type)
|
|
+{
|
|
+ struct audit_context *audit_cxt;
|
|
+
|
|
+ audit_cxt = apparmor_logsyscall ? current->audit_context : NULL;
|
|
+ return aa_audit_base(profile, sa, audit_cxt, type);
|
|
+}
|
|
+
|
|
+void aa_audit_hint(struct aa_profile *profile, struct aa_audit *sa)
|
|
+{
|
|
+ aa_audit_message(profile, sa, AUDIT_APPARMOR_HINT);
|
|
+}
|
|
+
|
|
+void aa_audit_status(struct aa_profile *profile, struct aa_audit *sa)
|
|
+{
|
|
+ aa_audit_message(profile, sa, AUDIT_APPARMOR_STATUS);
|
|
+}
|
|
+
|
|
+int aa_audit_reject(struct aa_profile *profile, struct aa_audit *sa)
|
|
+{
|
|
+ return aa_audit_message(profile, sa, AUDIT_APPARMOR_DENIED);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_audit - Log an audit event to the audit subsystem
|
|
+ * @profile: profile to check against
|
|
+ * @sa: audit event
|
|
+ */
|
|
+int aa_audit(struct aa_profile *profile, struct aa_audit *sa)
|
|
+{
|
|
+ int type = AUDIT_APPARMOR_DENIED;
|
|
+ struct audit_context *audit_cxt;
|
|
+
|
|
+ if (likely(!sa->error_code))
|
|
+ type = AUDIT_APPARMOR_AUDIT;
|
|
+ else if (PROFILE_COMPLAIN(profile))
|
|
+ type = AUDIT_APPARMOR_ALLOWED;
|
|
+
|
|
+ audit_cxt = apparmor_logsyscall ? current->audit_context : NULL;
|
|
+ return aa_audit_base(profile, sa, audit_cxt, type);
|
|
+}
|
|
+
|
|
+static int aa_audit_file(struct aa_profile *profile, struct aa_audit *sa)
|
|
+{
|
|
+ if (likely(!sa->error_code)) {
|
|
+ int mask = sa->audit_mask & AUDIT_FILE_MASK;
|
|
+
|
|
+ if (unlikely(PROFILE_AUDIT(profile)))
|
|
+ mask |= AUDIT_FILE_MASK;
|
|
+
|
|
+ if (likely(!(sa->request_mask & mask)))
|
|
+ return 0;
|
|
+
|
|
+ /* mask off perms that are not being force audited */
|
|
+ sa->request_mask &= mask | ALL_AA_EXEC_TYPE;
|
|
+ } else {
|
|
+ int mask = AUDIT_QUIET_MASK(sa->audit_mask);
|
|
+
|
|
+ if (!(sa->denied_mask & ~mask))
|
|
+ return sa->error_code;
|
|
+
|
|
+ /* mask off perms whose denial is being silenced */
|
|
+ sa->denied_mask &= (~mask) | ALL_AA_EXEC_TYPE;
|
|
+ }
|
|
+
|
|
+ return aa_audit(profile, sa);
|
|
+}
|
|
+
|
|
+static int aa_audit_caps(struct aa_profile *profile, struct aa_audit *sa,
|
|
+ int cap)
|
|
+{
|
|
+ if (likely(!sa->error_code)) {
|
|
+ if (likely(!PROFILE_AUDIT(profile) &&
|
|
+ !cap_raised(profile->audit_caps, cap)))
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ /* quieting of capabilities is handled the caps_logged cache */
|
|
+ return aa_audit(profile, sa);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_file_denied - check for @mask access on a file
|
|
+ * @profile: profile to check against
|
|
+ * @name: pathname of file
|
|
+ * @mask: permission mask requested for file
|
|
+ * @audit_mask: return audit mask for the match
|
|
+ *
|
|
+ * Return %0 on success, or else the permissions in @mask that the
|
|
+ * profile denies.
|
|
+ */
|
|
+static int aa_file_denied(struct aa_profile *profile, const char *name,
|
|
+ int mask, int *audit_mask)
|
|
+{
|
|
+ return (mask & ~aa_match(profile->file_rules, name, audit_mask));
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_link_denied - check for permission to link a file
|
|
+ * @profile: profile to check against
|
|
+ * @link: pathname of link being created
|
|
+ * @target: pathname of target to be linked to
|
|
+ * @target_mode: UGO shift for target inode
|
|
+ * @request_mask: the permissions subset valid only if link succeeds
|
|
+ * @audit_mask: return the audit_mask for the link permission
|
|
+ * Return %0 on success, or else the permissions that the profile denies.
|
|
+ */
|
|
+static int aa_link_denied(struct aa_profile *profile, const char *link,
|
|
+ const char *target, int target_mode,
|
|
+ int *request_mask, int *audit_mask)
|
|
+{
|
|
+ unsigned int state;
|
|
+ int l_mode, t_mode, l_x, t_x, denied_mask = 0;
|
|
+ int link_mask = AA_MAY_LINK << target_mode;
|
|
+
|
|
+ *request_mask = link_mask;
|
|
+
|
|
+ l_mode = aa_match_state(profile->file_rules, DFA_START, link, &state);
|
|
+
|
|
+ if (l_mode & link_mask) {
|
|
+ int mode;
|
|
+ /* test to see if target can be paired with link */
|
|
+ state = aa_dfa_null_transition(profile->file_rules, state);
|
|
+ mode = aa_match_state(profile->file_rules, state, target,
|
|
+ &state);
|
|
+
|
|
+ if (!(mode & link_mask))
|
|
+ denied_mask |= link_mask;
|
|
+
|
|
+ *audit_mask = dfa_audit_mask(profile->file_rules, state);
|
|
+
|
|
+ /* return if link subset test is not required */
|
|
+ if (!(mode & (AA_LINK_SUBSET_TEST << target_mode)))
|
|
+ return denied_mask;
|
|
+ }
|
|
+
|
|
+ /* Do link perm subset test requiring permission on link are a
|
|
+ * subset of the permissions on target.
|
|
+ * If a subset test is required a permission subset test of the
|
|
+ * perms for the link are done against the user::other of the
|
|
+ * target's 'r', 'w', 'x', 'a', 'k', and 'm' permissions.
|
|
+ *
|
|
+ * If the link has 'x', an exact match of all the execute flags
|
|
+ * must match.
|
|
+ */
|
|
+ denied_mask |= ~l_mode & link_mask;
|
|
+
|
|
+ t_mode = aa_match(profile->file_rules, target, NULL);
|
|
+
|
|
+ l_x = l_mode & (ALL_AA_EXEC_TYPE | AA_EXEC_BITS);
|
|
+ t_x = t_mode & (ALL_AA_EXEC_TYPE | AA_EXEC_BITS);
|
|
+
|
|
+ /* For actual subset test ignore valid-profile-transition flags,
|
|
+ * and link bits
|
|
+ */
|
|
+ l_mode &= AA_FILE_PERMS & ~AA_LINK_BITS;
|
|
+ t_mode &= AA_FILE_PERMS & ~AA_LINK_BITS;
|
|
+
|
|
+ *request_mask = l_mode | link_mask;
|
|
+
|
|
+ if (l_mode) {
|
|
+ int x = l_x | (t_x & ALL_AA_EXEC_UNSAFE);
|
|
+ denied_mask |= l_mode & ~t_mode;
|
|
+ /* mask off x modes not used by link */
|
|
+
|
|
+ /* handle exec subset
|
|
+ * - link safe exec issubset of unsafe exec
|
|
+ * - no link x perm is subset of target having x perm
|
|
+ */
|
|
+ if ((l_mode & AA_USER_EXEC) &&
|
|
+ (x & AA_USER_EXEC_TYPE) != (t_x & AA_USER_EXEC_TYPE))
|
|
+ denied_mask = AA_USER_EXEC | (l_x & AA_USER_EXEC_TYPE);
|
|
+ if ((l_mode & AA_OTHER_EXEC) &&
|
|
+ (x & AA_OTHER_EXEC_TYPE) != (t_x & AA_OTHER_EXEC_TYPE))
|
|
+ denied_mask = AA_OTHER_EXEC | (l_x & AA_OTHER_EXEC_TYPE);
|
|
+ }
|
|
+
|
|
+ return denied_mask;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_get_name - compute the pathname of a file
|
|
+ * @dentry: dentry of the file
|
|
+ * @mnt: vfsmount of the file
|
|
+ * @buffer: buffer that aa_get_name() allocated
|
|
+ * @check: AA_CHECK_DIR is set if the file is a directory
|
|
+ *
|
|
+ * Returns a pointer to the beginning of the pathname (which usually differs
|
|
+ * from the beginning of the buffer), or an error code.
|
|
+ *
|
|
+ * We need @check to indicate whether the file is a directory or not because
|
|
+ * the file may not yet exist, and so we cannot check the inode's file type.
|
|
+ */
|
|
+static char *aa_get_name(struct dentry *dentry, struct vfsmount *mnt,
|
|
+ char **buffer, int check)
|
|
+{
|
|
+ char *name;
|
|
+ int is_dir, size = 256;
|
|
+
|
|
+ is_dir = (check & AA_CHECK_DIR) ? 1 : 0;
|
|
+
|
|
+ for (;;) {
|
|
+ char *buf = kmalloc(size, GFP_KERNEL);
|
|
+ if (!buf)
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+
|
|
+ name = d_namespace_path(dentry, mnt, buf, size - is_dir);
|
|
+ if (!IS_ERR(name)) {
|
|
+ if (name[0] != '/') {
|
|
+ /*
|
|
+ * This dentry is not connected to the
|
|
+ * namespace root -- reject access.
|
|
+ */
|
|
+ kfree(buf);
|
|
+ return ERR_PTR(-ENOENT);
|
|
+ }
|
|
+ if (is_dir && name[1] != '\0') {
|
|
+ /*
|
|
+ * Append "/" to the pathname. The root
|
|
+ * directory is a special case; it already
|
|
+ * ends in slash.
|
|
+ */
|
|
+ buf[size - 2] = '/';
|
|
+ buf[size - 1] = '\0';
|
|
+ }
|
|
+
|
|
+ *buffer = buf;
|
|
+ return name;
|
|
+ }
|
|
+ if (PTR_ERR(name) != -ENAMETOOLONG)
|
|
+ return name;
|
|
+
|
|
+ kfree(buf);
|
|
+ size <<= 1;
|
|
+ if (size > apparmor_path_max)
|
|
+ return ERR_PTR(-ENAMETOOLONG);
|
|
+ }
|
|
+}
|
|
+
|
|
+static char *new_compound_name(const char *n1, const char *n2)
|
|
+{
|
|
+ char *name = kmalloc(strlen(n1) + strlen(n2) + 3, GFP_KERNEL);
|
|
+ if (name)
|
|
+ sprintf(name, "%s//%s", n1, n2);
|
|
+ return name;
|
|
+}
|
|
+static inline void aa_put_name_buffer(char *buffer)
|
|
+{
|
|
+ kfree(buffer);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_perm_dentry - check if @profile allows @mask for a file
|
|
+ * @profile: profile to check against
|
|
+ * @dentry: dentry of the file
|
|
+ * @mnt: vfsmount o the file
|
|
+ * @sa: audit context
|
|
+ * @mask: requested profile permissions
|
|
+ * @check: kind of check to perform
|
|
+ *
|
|
+ * Returns 0 upon success, or else an error code.
|
|
+ *
|
|
+ * @check indicates the file type, and whether the file was accessed through
|
|
+ * an open file descriptor (AA_CHECK_FD) or not.
|
|
+ */
|
|
+static int aa_perm_dentry(struct aa_profile *profile, struct dentry *dentry,
|
|
+ struct vfsmount *mnt, struct aa_audit *sa, int check)
|
|
+{
|
|
+ int error;
|
|
+ char *buffer = NULL;
|
|
+
|
|
+ sa->name = aa_get_name(dentry, mnt, &buffer, check);
|
|
+ sa->request_mask <<= aa_inode_mode(dentry->d_inode);
|
|
+ if (IS_ERR(sa->name)) {
|
|
+ /*
|
|
+ * deleted files are given a pass on permission checks when
|
|
+ * accessed through a file descriptor.
|
|
+ */
|
|
+ if (PTR_ERR(sa->name) == -ENOENT && (check & AA_CHECK_FD))
|
|
+ sa->denied_mask = 0;
|
|
+ else {
|
|
+ sa->denied_mask = sa->request_mask;
|
|
+ sa->error_code = PTR_ERR(sa->name);
|
|
+ if (sa->error_code == -ENOENT)
|
|
+ sa->info = "Failed name resolution - object not a valid entry";
|
|
+ else if (sa->error_code == -ENAMETOOLONG)
|
|
+ sa->info = "Failed name resolution - name too long";
|
|
+ else
|
|
+ sa->info = "Failed name resolution";
|
|
+ }
|
|
+ sa->name = NULL;
|
|
+ } else
|
|
+ sa->denied_mask = aa_file_denied(profile, sa->name,
|
|
+ sa->request_mask,
|
|
+ &sa->audit_mask);
|
|
+
|
|
+ if (!sa->denied_mask)
|
|
+ sa->error_code = 0;
|
|
+
|
|
+ error = aa_audit_file(profile, sa);
|
|
+ aa_put_name_buffer(buffer);
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_attr - check if attribute change is allowed
|
|
+ * @profile: profile to check against
|
|
+ * @dentry: dentry of the file to check
|
|
+ * @mnt: vfsmount of the file to check
|
|
+ * @iattr: attribute changes requested
|
|
+ */
|
|
+int aa_attr(struct aa_profile *profile, struct dentry *dentry,
|
|
+ struct vfsmount *mnt, struct iattr *iattr)
|
|
+{
|
|
+ struct inode *inode = dentry->d_inode;
|
|
+ int error, check;
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "setattr";
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.iattr = iattr;
|
|
+ sa.request_mask = MAY_WRITE;
|
|
+ sa.error_code = -EACCES;
|
|
+
|
|
+ check = 0;
|
|
+ if (inode && S_ISDIR(inode->i_mode))
|
|
+ check |= AA_CHECK_DIR;
|
|
+ if (iattr->ia_valid & ATTR_FILE)
|
|
+ check |= AA_CHECK_FD;
|
|
+
|
|
+ error = aa_perm_dentry(profile, dentry, mnt, &sa, check);
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_perm_xattr - check if xattr attribute change is allowed
|
|
+ * @profile: profile to check against
|
|
+ * @dentry: dentry of the file to check
|
|
+ * @mnt: vfsmount of the file to check
|
|
+ * @operation: xattr operation being done
|
|
+ * @mask: access mode requested
|
|
+ * @check: kind of check to perform
|
|
+ */
|
|
+int aa_perm_xattr(struct aa_profile *profile, const char *operation,
|
|
+ struct dentry *dentry, struct vfsmount *mnt, int mask,
|
|
+ int check)
|
|
+{
|
|
+ struct inode *inode = dentry->d_inode;
|
|
+ int error;
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = operation;
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.request_mask = mask;
|
|
+ sa.error_code = -EACCES;
|
|
+
|
|
+ if (inode && S_ISDIR(inode->i_mode))
|
|
+ check |= AA_CHECK_DIR;
|
|
+
|
|
+ error = aa_perm_dentry(profile, dentry, mnt, &sa, check);
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_perm - basic apparmor permissions check
|
|
+ * @profile: profile to check against
|
|
+ * @dentry: dentry of the file to check
|
|
+ * @mnt: vfsmount of the file to check
|
|
+ * @mask: access mode requested
|
|
+ * @check: kind of check to perform
|
|
+ *
|
|
+ * Determine if access @mask for the file is authorized by @profile.
|
|
+ * Returns 0 on success, or else an error code.
|
|
+ */
|
|
+int aa_perm(struct aa_profile *profile, const char *operation,
|
|
+ struct dentry *dentry, struct vfsmount *mnt, int mask, int check)
|
|
+{
|
|
+ struct aa_audit sa;
|
|
+ int error = 0;
|
|
+
|
|
+ if (mask == 0)
|
|
+ goto out;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = operation;
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.request_mask = mask;
|
|
+ sa.error_code = -EACCES;
|
|
+
|
|
+ error = aa_perm_dentry(profile, dentry, mnt, &sa, check);
|
|
+
|
|
+out:
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_perm_dir
|
|
+ * @profile: profile to check against
|
|
+ * @dentry: dentry of directory to check
|
|
+ * @mnt: vfsmount of directory to check
|
|
+ * @operation: directory operation being performed
|
|
+ * @mask: access mode requested
|
|
+ *
|
|
+ * Determine if directory operation (make/remove) for dentry is authorized
|
|
+ * by @profile.
|
|
+ * Returns 0 on success, or else an error code.
|
|
+ */
|
|
+int aa_perm_dir(struct aa_profile *profile, const char *operation,
|
|
+ struct dentry *dentry, struct vfsmount *mnt, int mask)
|
|
+{
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = operation;
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.request_mask = mask;
|
|
+ sa.error_code = -EACCES;
|
|
+
|
|
+ return aa_perm_dentry(profile, dentry, mnt, &sa, AA_CHECK_DIR);
|
|
+}
|
|
+
|
|
+int aa_perm_path(struct aa_profile *profile, const char *operation,
|
|
+ const char *name, int mask, uid_t uid)
|
|
+{
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = operation;
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.request_mask = mask;
|
|
+ sa.name = name;
|
|
+ if (current->fsuid == uid)
|
|
+ sa.request_mask = mask << AA_USER_SHIFT;
|
|
+ else
|
|
+ sa.request_mask = mask << AA_OTHER_SHIFT;
|
|
+
|
|
+ sa.denied_mask = aa_file_denied(profile, name, sa.request_mask,
|
|
+ &sa.audit_mask) ;
|
|
+ sa.error_code = sa.denied_mask ? -EACCES : 0;
|
|
+
|
|
+ return aa_audit_file(profile, &sa);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_capability - test permission to use capability
|
|
+ * @cxt: aa_task_context with profile to check against
|
|
+ * @cap: capability to be tested
|
|
+ *
|
|
+ * Look up capability in profile capability set.
|
|
+ * Returns 0 on success, or else an error code.
|
|
+ */
|
|
+int aa_capability(struct aa_task_context *cxt, int cap)
|
|
+{
|
|
+ int error = cap_raised(cxt->profile->capabilities, cap) ? 0 : -EPERM;
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ /* test if cap has alread been logged */
|
|
+ if (cap_raised(cxt->caps_logged, cap)) {
|
|
+ if (PROFILE_COMPLAIN(cxt->profile))
|
|
+ error = 0;
|
|
+ return error;
|
|
+ } else
|
|
+ /* don't worry about rcu replacement of the cxt here.
|
|
+ * caps_logged is a cache to reduce the occurence of
|
|
+ * duplicate messages in the log. The worst that can
|
|
+ * happen is duplicate capability messages shows up in
|
|
+ * the audit log
|
|
+ */
|
|
+ cap_raise(cxt->caps_logged, cap);
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "capable";
|
|
+ sa.gfp_mask = GFP_ATOMIC;
|
|
+ sa.name = capability_names[cap];
|
|
+ sa.error_code = error;
|
|
+
|
|
+ error = aa_audit_caps(cxt->profile, &sa, cap);
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/* must be used inside rcu_read_lock or task_lock */
|
|
+int aa_may_ptrace(struct aa_task_context *cxt, struct aa_profile *tracee)
|
|
+{
|
|
+ if (!cxt || cxt->profile == tracee)
|
|
+ return 0;
|
|
+ return aa_capability(cxt, CAP_SYS_PTRACE);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_link - hard link check
|
|
+ * @profile: profile to check against
|
|
+ * @link: dentry of link being created
|
|
+ * @link_mnt: vfsmount of link being created
|
|
+ * @target: dentry of link target
|
|
+ * @target_mnt: vfsmunt of link target
|
|
+ *
|
|
+ * Returns 0 on success, or else an error code.
|
|
+ */
|
|
+int aa_link(struct aa_profile *profile,
|
|
+ struct dentry *link, struct vfsmount *link_mnt,
|
|
+ struct dentry *target, struct vfsmount *target_mnt)
|
|
+{
|
|
+ int error;
|
|
+ struct aa_audit sa;
|
|
+ char *buffer = NULL, *buffer2 = NULL;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "inode_link";
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.name = aa_get_name(link, link_mnt, &buffer, 0);
|
|
+ sa.name2 = aa_get_name(target, target_mnt, &buffer2, 0);
|
|
+
|
|
+ if (IS_ERR(sa.name)) {
|
|
+ sa.error_code = PTR_ERR(sa.name);
|
|
+ sa.name = NULL;
|
|
+ }
|
|
+ if (IS_ERR(sa.name2)) {
|
|
+ sa.error_code = PTR_ERR(sa.name2);
|
|
+ sa.name2 = NULL;
|
|
+ }
|
|
+
|
|
+ if (sa.name && sa.name2) {
|
|
+ sa.denied_mask = aa_link_denied(profile, sa.name, sa.name2,
|
|
+ aa_inode_mode(target->d_inode),
|
|
+ &sa.request_mask,
|
|
+ &sa.audit_mask);
|
|
+ sa.error_code = sa.denied_mask ? -EACCES : 0;
|
|
+ }
|
|
+
|
|
+ error = aa_audit_file(profile, &sa);
|
|
+
|
|
+ aa_put_name_buffer(buffer);
|
|
+ aa_put_name_buffer(buffer2);
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/*******************************
|
|
+ * Global task related functions
|
|
+ *******************************/
|
|
+
|
|
+/**
|
|
+ * aa_clone - initialize the task context for a new task
|
|
+ * @child: task that is being created
|
|
+ *
|
|
+ * Returns 0 on success, or else an error code.
|
|
+ */
|
|
+int aa_clone(struct task_struct *child)
|
|
+{
|
|
+ struct aa_task_context *cxt, *child_cxt;
|
|
+ struct aa_profile *profile;
|
|
+
|
|
+ if (!aa_task_context(current))
|
|
+ return 0;
|
|
+ child_cxt = aa_alloc_task_context(GFP_KERNEL);
|
|
+ if (!child_cxt)
|
|
+ return -ENOMEM;
|
|
+
|
|
+repeat:
|
|
+ profile = aa_get_profile(current);
|
|
+ if (profile) {
|
|
+ lock_profile(profile);
|
|
+ cxt = aa_task_context(current);
|
|
+ if (unlikely(profile->isstale || !cxt ||
|
|
+ cxt->profile != profile)) {
|
|
+ /**
|
|
+ * Race with profile replacement or removal, or with
|
|
+ * task context removal.
|
|
+ */
|
|
+ unlock_profile(profile);
|
|
+ aa_put_profile(profile);
|
|
+ goto repeat;
|
|
+ }
|
|
+
|
|
+ /* No need to grab the child's task lock here. */
|
|
+ aa_change_task_context(child, child_cxt, profile,
|
|
+ cxt->cookie, cxt->previous_profile);
|
|
+ unlock_profile(profile);
|
|
+
|
|
+ if (APPARMOR_COMPLAIN(child_cxt) &&
|
|
+ profile == profile->ns->null_complain_profile) {
|
|
+ struct aa_audit sa;
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "clone";
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.task = child->pid;
|
|
+ aa_audit_hint(profile, &sa);
|
|
+ }
|
|
+ aa_put_profile(profile);
|
|
+ } else
|
|
+ aa_free_task_context(child_cxt);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static struct aa_profile *
|
|
+aa_register_find(struct aa_profile *profile, const char* ns_name,
|
|
+ const char *name, int mandatory, int complain,
|
|
+ struct aa_audit *sa)
|
|
+{
|
|
+ struct aa_namespace *ns;
|
|
+ struct aa_profile *new_profile;
|
|
+ int ns_ref = 0;
|
|
+
|
|
+ if (profile)
|
|
+ ns = profile->ns;
|
|
+ else
|
|
+ ns = default_namespace;
|
|
+
|
|
+ if (ns_name) {
|
|
+ /* locate the profile namespace */
|
|
+ ns = aa_find_namespace(ns_name);
|
|
+ if (!ns) {
|
|
+ if (mandatory) {
|
|
+ sa->info = "profile namespace not found";
|
|
+ sa->denied_mask = sa->request_mask;
|
|
+ sa->error_code = -ENOENT;
|
|
+ return ERR_PTR(-ENOENT);
|
|
+ } else {
|
|
+ return NULL;
|
|
+ }
|
|
+ }
|
|
+ ns_ref++;
|
|
+ }
|
|
+
|
|
+ /* Locate new profile */
|
|
+ new_profile = aa_find_profile(ns, name);
|
|
+
|
|
+ if (new_profile) {
|
|
+ AA_DEBUG("%s: setting profile %s\n",
|
|
+ __FUNCTION__, new_profile->name);
|
|
+ } else if (mandatory && profile) {
|
|
+ sa->info = "mandatory profile missing";
|
|
+ sa->denied_mask = sa->request_mask; /* shifted MAY_EXEC */
|
|
+ if (complain) {
|
|
+ aa_audit_hint(profile, sa);
|
|
+ new_profile =
|
|
+ aa_dup_profile(profile->ns->null_complain_profile);
|
|
+ } else {
|
|
+ sa->error_code = -EACCES;
|
|
+ if (ns_ref)
|
|
+ aa_put_namespace(ns);
|
|
+ return ERR_PTR(-EACCES);
|
|
+ }
|
|
+ } else {
|
|
+ /* Only way we can get into this code is if task
|
|
+ * is unconfined, pix, nix.
|
|
+ */
|
|
+ AA_DEBUG("%s: No profile found for exec image '%s'\n",
|
|
+ __FUNCTION__,
|
|
+ name);
|
|
+ }
|
|
+ if (ns_ref)
|
|
+ aa_put_namespace(ns);
|
|
+ return new_profile;
|
|
+}
|
|
+
|
|
+static struct aa_profile *
|
|
+aa_x_to_profile(struct aa_profile *profile, const char *filename, int xmode,
|
|
+ struct aa_audit *sa, char **child)
|
|
+{
|
|
+ struct aa_profile *new_profile = NULL;
|
|
+ int ix = xmode & AA_EXEC_INHERIT;
|
|
+ int complain = PROFILE_COMPLAIN(profile);
|
|
+ int index;
|
|
+
|
|
+ *child = NULL;
|
|
+ switch (xmode & AA_EXEC_MODIFIERS) {
|
|
+ case 0:
|
|
+ /* only valid with ix flag */
|
|
+ ix = 1;
|
|
+ break;
|
|
+ case AA_EXEC_UNCONFINED:
|
|
+ /* only valid without ix flag */
|
|
+ ix = 0;
|
|
+ break;
|
|
+ case AA_EXEC_PROFILE:
|
|
+ new_profile = aa_register_find(profile, NULL, filename, !ix,
|
|
+ complain, sa);
|
|
+ break;
|
|
+ case AA_EXEC_CHILD:
|
|
+ *child = new_compound_name(profile->name, filename);
|
|
+ sa->name2 = *child;
|
|
+ if (!*child) {
|
|
+ sa->info = "Failed name resolution - exec failed";
|
|
+ sa->error_code = -ENOMEM;
|
|
+ new_profile = ERR_PTR(-ENOMEM);
|
|
+ } else {
|
|
+ new_profile = aa_register_find(profile, NULL, *child,
|
|
+ !ix, complain, sa);
|
|
+ }
|
|
+ break;
|
|
+ default:
|
|
+ /* all other indexes are named transitions */
|
|
+ index = AA_EXEC_INDEX(xmode);
|
|
+ if (index - 4 > profile->exec_table_size) {
|
|
+ sa->info = "invalid named transition - exec failed";
|
|
+ sa->error_code = -EACCES;
|
|
+ new_profile = ERR_PTR(-EACCES);
|
|
+ } else {
|
|
+ char *ns_name = NULL;
|
|
+ char *name = profile->exec_table[index - 4];
|
|
+ if (*name == ':') {
|
|
+ ns_name = name + 1;
|
|
+ name = ns_name + strlen(ns_name) + 1;
|
|
+ }
|
|
+ sa->name2 = name;
|
|
+ sa->name3 = ns_name;
|
|
+ new_profile =
|
|
+ aa_register_find(profile, ns_name, name,
|
|
+ !ix, complain, sa);
|
|
+ }
|
|
+ }
|
|
+ if (IS_ERR(new_profile))
|
|
+ /* all these failures must be audited - no quieting */
|
|
+ return ERR_PTR(aa_audit_reject(profile, sa));
|
|
+ return new_profile;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_register - register a new program
|
|
+ * @bprm: binprm of program being registered
|
|
+ *
|
|
+ * Try to register a new program during execve(). This should give the
|
|
+ * new program a valid aa_task_context if confined.
|
|
+ */
|
|
+int aa_register(struct linux_binprm *bprm)
|
|
+{
|
|
+ const char *filename;
|
|
+ char *buffer = NULL, *child = NULL;
|
|
+ struct file *filp = bprm->file;
|
|
+ struct aa_profile *profile, *old_profile, *new_profile = NULL;
|
|
+ int exec_mode, complain = 0, shift;
|
|
+ struct aa_audit sa;
|
|
+
|
|
+ AA_DEBUG("%s\n", __FUNCTION__);
|
|
+
|
|
+ profile = aa_get_profile(current);
|
|
+
|
|
+ shift = aa_inode_mode(filp->f_dentry->d_inode);
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.operation = "exec";
|
|
+ sa.gfp_mask = GFP_KERNEL;
|
|
+ sa.request_mask = MAY_EXEC << shift;
|
|
+
|
|
+ filename = aa_get_name(filp->f_dentry, filp->f_vfsmnt, &buffer, 0);
|
|
+ if (IS_ERR(filename)) {
|
|
+ if (profile) {
|
|
+ sa.info = "Failed name resolution - exec failed";
|
|
+ sa.error_code = PTR_ERR(filename);
|
|
+ aa_audit_file(profile, &sa);
|
|
+ return sa.error_code;
|
|
+ } else
|
|
+ return 0;
|
|
+ }
|
|
+ sa.name = filename;
|
|
+
|
|
+ exec_mode = AA_EXEC_UNSAFE << shift;
|
|
+
|
|
+repeat:
|
|
+ if (profile) {
|
|
+ complain = PROFILE_COMPLAIN(profile);
|
|
+
|
|
+ /* Confined task, determine what mode inherit, unconfined or
|
|
+ * mandatory to load new profile
|
|
+ */
|
|
+ exec_mode = aa_match(profile->file_rules, filename,
|
|
+ &sa.audit_mask);
|
|
+
|
|
+
|
|
+ if (exec_mode & sa.request_mask) {
|
|
+ int xm = exec_mode >> shift;
|
|
+ new_profile = aa_x_to_profile(profile, filename,
|
|
+ xm, &sa, &child);
|
|
+
|
|
+ if (!new_profile && (xm & AA_EXEC_INHERIT))
|
|
+ /* (p|c|n|)ix - don't change profile */
|
|
+ goto cleanup;
|
|
+ /* error case caught below */
|
|
+
|
|
+ } else if (sa.request_mask & AUDIT_QUIET_MASK(sa.audit_mask)) {
|
|
+ /* quiet failed exit */
|
|
+ new_profile = ERR_PTR(-EACCES);
|
|
+ } else if (complain) {
|
|
+ /* There was no entry in calling profile
|
|
+ * describing mode to execute image in.
|
|
+ * Drop into null-profile (disabling secure exec).
|
|
+ */
|
|
+ new_profile =
|
|
+ aa_dup_profile(profile->ns->null_complain_profile);
|
|
+ exec_mode |= AA_EXEC_UNSAFE << shift;
|
|
+ } else {
|
|
+ sa.denied_mask = sa.request_mask;
|
|
+ sa.error_code = -EACCES;
|
|
+ new_profile = ERR_PTR(aa_audit_file(profile, &sa));
|
|
+ }
|
|
+ } else {
|
|
+ /* Unconfined task, load profile if it exists */
|
|
+ new_profile = aa_register_find(NULL, NULL, filename, 0, 0, &sa);
|
|
+ if (new_profile == NULL)
|
|
+ goto cleanup;
|
|
+ }
|
|
+
|
|
+ if (IS_ERR(new_profile))
|
|
+ goto cleanup;
|
|
+
|
|
+ old_profile = __aa_replace_profile(current, new_profile);
|
|
+ if (IS_ERR(old_profile)) {
|
|
+ aa_put_profile(new_profile);
|
|
+ aa_put_profile(profile);
|
|
+ if (PTR_ERR(old_profile) == -ESTALE) {
|
|
+ profile = aa_get_profile(current);
|
|
+ goto repeat;
|
|
+ }
|
|
+ if (PTR_ERR(old_profile) == -EPERM) {
|
|
+ sa.denied_mask = sa.request_mask;
|
|
+ sa.info = "unable to set profile due to ptrace";
|
|
+ sa.task = current->parent->pid;
|
|
+ aa_audit_reject(profile, &sa);
|
|
+ }
|
|
+ new_profile = old_profile;
|
|
+ goto cleanup;
|
|
+ }
|
|
+ aa_put_profile(old_profile);
|
|
+ aa_put_profile(profile);
|
|
+
|
|
+ /* Handle confined exec.
|
|
+ * Can be at this point for the following reasons:
|
|
+ * 1. unconfined switching to confined
|
|
+ * 2. confined switching to different confinement
|
|
+ * 3. confined switching to unconfined
|
|
+ *
|
|
+ * Cases 2 and 3 are marked as requiring secure exec
|
|
+ * (unless policy specified "unsafe exec")
|
|
+ */
|
|
+ if (!(exec_mode & (AA_EXEC_UNSAFE << shift))) {
|
|
+ unsigned long bprm_flags;
|
|
+
|
|
+ bprm_flags = AA_SECURE_EXEC_NEEDED;
|
|
+ bprm->security = (void*)
|
|
+ ((unsigned long)bprm->security | bprm_flags);
|
|
+ }
|
|
+
|
|
+ if (complain && new_profile &&
|
|
+ new_profile == new_profile->ns->null_complain_profile) {
|
|
+ sa.request_mask = 0;
|
|
+ sa.name = NULL;
|
|
+ sa.info = "set profile";
|
|
+ aa_audit_hint(new_profile, &sa);
|
|
+ }
|
|
+
|
|
+cleanup:
|
|
+ aa_put_name_buffer(child);
|
|
+ aa_put_name_buffer(buffer);
|
|
+ if (IS_ERR(new_profile))
|
|
+ return PTR_ERR(new_profile);
|
|
+ aa_put_profile(new_profile);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_release - release a task context
|
|
+ * @task: task being released
|
|
+ *
|
|
+ * This is called after a task has exited and the parent has reaped it.
|
|
+ */
|
|
+void aa_release(struct task_struct *task)
|
|
+{
|
|
+ struct aa_task_context *cxt;
|
|
+ struct aa_profile *profile;
|
|
+ /*
|
|
+ * While the task context is still on a profile's task context
|
|
+ * list, another process could replace the profile under us,
|
|
+ * leaving us with a locked profile that is no longer attached
|
|
+ * to this task. So after locking the profile, we check that
|
|
+ * the profile is still attached. The profile lock is
|
|
+ * sufficient to prevent the replacement race so we do not lock
|
|
+ * the task.
|
|
+ *
|
|
+ * Use lock subtyping to avoid lockdep reporting a false irq
|
|
+ * possible inversion between the task_lock and profile_lock
|
|
+ *
|
|
+ * We also avoid taking the task_lock here because lock_dep
|
|
+ * would report another false {softirq-on-W} potential irq_lock
|
|
+ * inversion.
|
|
+ *
|
|
+ * If the task does not have a profile attached we are safe;
|
|
+ * nothing can race with us at this point.
|
|
+ */
|
|
+
|
|
+repeat:
|
|
+ profile = aa_get_profile(task);
|
|
+ if (profile) {
|
|
+ lock_profile_nested(profile, aa_lock_task_release);
|
|
+ cxt = aa_task_context(task);
|
|
+ if (unlikely(!cxt || cxt->profile != profile)) {
|
|
+ unlock_profile(profile);
|
|
+ aa_put_profile(profile);
|
|
+ goto repeat;
|
|
+ }
|
|
+ aa_change_task_context(task, NULL, NULL, 0, NULL);
|
|
+ unlock_profile(profile);
|
|
+ aa_put_profile(profile);
|
|
+ }
|
|
+}
|
|
+
|
|
+static int do_change_profile(struct aa_profile *expected,
|
|
+ struct aa_namespace *ns, const char *name,
|
|
+ u64 cookie, int restore, int hat,
|
|
+ struct aa_audit *sa)
|
|
+{
|
|
+ struct aa_profile *new_profile = NULL, *old_profile = NULL,
|
|
+ *previous_profile = NULL;
|
|
+ struct aa_task_context *new_cxt, *cxt;
|
|
+ int error = 0;
|
|
+
|
|
+ sa->name = name;
|
|
+
|
|
+ new_cxt = aa_alloc_task_context(GFP_KERNEL);
|
|
+ if (!new_cxt)
|
|
+ return -ENOMEM;
|
|
+
|
|
+ new_profile = aa_find_profile(ns, name);
|
|
+ if (!new_profile && !restore) {
|
|
+ if (!PROFILE_COMPLAIN(expected)) {
|
|
+ aa_free_task_context(new_cxt);
|
|
+ return -ENOENT;
|
|
+ }
|
|
+ new_profile = aa_dup_profile(ns->null_complain_profile);
|
|
+ } else if (new_profile && hat && !PROFILE_IS_HAT(new_profile)) {
|
|
+ aa_free_task_context(new_cxt);
|
|
+ aa_put_profile(new_profile);
|
|
+ return error;
|
|
+ }
|
|
+
|
|
+ cxt = lock_task_and_profiles(current, new_profile);
|
|
+ if (!cxt) {
|
|
+ error = -EPERM;
|
|
+ goto out;
|
|
+ }
|
|
+ old_profile = cxt->profile;
|
|
+
|
|
+ if (cxt->profile != expected || (new_profile && new_profile->isstale)) {
|
|
+ error = -ESTALE;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ if (cxt->previous_profile) {
|
|
+ if (cxt->cookie != cookie) {
|
|
+ error = -EACCES;
|
|
+ sa->info = "killing process";
|
|
+ aa_audit_reject(cxt->profile, sa);
|
|
+ /* terminate process */
|
|
+ (void)send_sig_info(SIGKILL, NULL, current);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ if (!restore)
|
|
+ previous_profile = cxt->previous_profile;
|
|
+ } else
|
|
+ previous_profile = cxt->profile;
|
|
+
|
|
+ if ((current->ptrace & PT_PTRACED) && aa_may_ptrace(cxt, new_profile)) {
|
|
+ error = -EACCES;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ if (new_profile == ns->null_complain_profile)
|
|
+ aa_audit_hint(cxt->profile, sa);
|
|
+
|
|
+ if (APPARMOR_AUDIT(cxt))
|
|
+ aa_audit_message(cxt->profile, sa, AUDIT_APPARMOR_AUDIT);
|
|
+
|
|
+ if (!restore && cookie)
|
|
+ aa_change_task_context(current, new_cxt, new_profile, cookie,
|
|
+ previous_profile);
|
|
+ else
|
|
+ /* either return to previous_profile, or a permanent change */
|
|
+ aa_change_task_context(current, new_cxt, new_profile, 0, NULL);
|
|
+
|
|
+out:
|
|
+ if (aa_task_context(current) != new_cxt)
|
|
+ aa_free_task_context(new_cxt);
|
|
+ task_unlock(current);
|
|
+ unlock_both_profiles(old_profile, new_profile);
|
|
+ aa_put_profile(new_profile);
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_change_profile - perform a one-way profile transition
|
|
+ * @ns_name: name of the profile namespace to change to
|
|
+ * @name: name of profile to change to
|
|
+ * Change to new profile @name. Unlike with hats, there is no way
|
|
+ * to change back.
|
|
+ *
|
|
+ * Returns %0 on success, error otherwise.
|
|
+ */
|
|
+int aa_change_profile(const char *ns_name, const char *name)
|
|
+{
|
|
+ struct aa_task_context *cxt;
|
|
+ struct aa_profile *profile = NULL;
|
|
+ struct aa_namespace *ns = NULL;
|
|
+ struct aa_audit sa;
|
|
+ unsigned int state;
|
|
+ int error = -EINVAL;
|
|
+
|
|
+ if (!name)
|
|
+ return -EINVAL;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.gfp_mask = GFP_ATOMIC;
|
|
+ sa.operation = "change_profile";
|
|
+
|
|
+repeat:
|
|
+ task_lock(current);
|
|
+ cxt = aa_task_context(current);
|
|
+ if (cxt)
|
|
+ profile = aa_dup_profile(cxt->profile);
|
|
+ task_unlock(current);
|
|
+
|
|
+ if (ns_name)
|
|
+ ns = aa_find_namespace(ns_name);
|
|
+ else if (profile)
|
|
+ ns = aa_get_namespace(profile->ns);
|
|
+ else
|
|
+ ns = aa_get_namespace(default_namespace);
|
|
+
|
|
+ if (!ns) {
|
|
+ aa_put_profile(profile);
|
|
+ return -ENOENT;
|
|
+ }
|
|
+
|
|
+ if (!profile || PROFILE_COMPLAIN(profile) ||
|
|
+ (ns == profile->ns &&
|
|
+ (aa_match(profile->file_rules, name, NULL) & AA_CHANGE_PROFILE)))
|
|
+ error = do_change_profile(profile, ns, name, 0, 0, 0, &sa);
|
|
+ else {
|
|
+ /* check for a rule with a namespace prepended */
|
|
+ aa_match_state(profile->file_rules, DFA_START, ns->name,
|
|
+ &state);
|
|
+ state = aa_dfa_null_transition(profile->file_rules, state);
|
|
+ if ((aa_match_state(profile->file_rules, state, name, NULL) &
|
|
+ AA_CHANGE_PROFILE))
|
|
+ error = do_change_profile(profile, ns, name, 0, 0, 0,
|
|
+ &sa);
|
|
+ else
|
|
+ /* no permission to transition to profile @name */
|
|
+ error = -EACCES;
|
|
+ }
|
|
+
|
|
+ aa_put_namespace(ns);
|
|
+ aa_put_profile(profile);
|
|
+ if (error == -ESTALE)
|
|
+ goto repeat;
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_change_hat - change hat to/from subprofile
|
|
+ * @hat_name: hat to change to
|
|
+ * @cookie: magic value to validate the hat change
|
|
+ *
|
|
+ * Change to new @hat_name, and store the @hat_magic in the current task
|
|
+ * context. If the new @hat_name is %NULL and the @cookie matches that
|
|
+ * stored in the current task context and is not 0, return to the top level
|
|
+ * profile.
|
|
+ * Returns %0 on success, error otherwise.
|
|
+ */
|
|
+int aa_change_hat(const char *hat_name, u64 cookie)
|
|
+{
|
|
+ struct aa_task_context *cxt;
|
|
+ struct aa_profile *profile, *previous_profile;
|
|
+ struct aa_audit sa;
|
|
+ int error = 0;
|
|
+
|
|
+ memset(&sa, 0, sizeof(sa));
|
|
+ sa.gfp_mask = GFP_ATOMIC;
|
|
+ sa.operation = "change_hat";
|
|
+
|
|
+repeat:
|
|
+ task_lock(current);
|
|
+ cxt = aa_task_context(current);
|
|
+ if (!cxt) {
|
|
+ task_unlock(current);
|
|
+ return -EPERM;
|
|
+ }
|
|
+ profile = aa_dup_profile(cxt->profile);
|
|
+ previous_profile = aa_dup_profile(cxt->previous_profile);
|
|
+ task_unlock(current);
|
|
+
|
|
+ if (hat_name) {
|
|
+ char *name, *profile_name;
|
|
+
|
|
+ if (previous_profile)
|
|
+ profile_name = previous_profile->name;
|
|
+ else
|
|
+ profile_name = profile->name;
|
|
+
|
|
+ name = new_compound_name(profile_name, hat_name);
|
|
+ if (!name) {
|
|
+ error = -ENOMEM;
|
|
+ goto out;
|
|
+ }
|
|
+ error = do_change_profile(profile, profile->ns, name, cookie,
|
|
+ 0, 1, &sa);
|
|
+ aa_put_name_buffer(name);
|
|
+ } else if (previous_profile)
|
|
+ error = do_change_profile(profile, profile->ns,
|
|
+ previous_profile->name, cookie, 1, 0,
|
|
+ &sa);
|
|
+ /* else ignore restores when there is no saved profile */
|
|
+
|
|
+out:
|
|
+ aa_put_profile(previous_profile);
|
|
+ aa_put_profile(profile);
|
|
+ if (error == -ESTALE)
|
|
+ goto repeat;
|
|
+
|
|
+ return error;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * __aa_replace_profile - replace a task's profile
|
|
+ * @task: task to switch the profile of
|
|
+ * @profile: profile to switch to
|
|
+ *
|
|
+ * Returns a handle to the previous profile upon success, or else an
|
|
+ * error code.
|
|
+ */
|
|
+struct aa_profile *__aa_replace_profile(struct task_struct *task,
|
|
+ struct aa_profile *profile)
|
|
+{
|
|
+ struct aa_task_context *cxt, *new_cxt = NULL;
|
|
+ struct aa_profile *old_profile = NULL;
|
|
+
|
|
+ if (profile) {
|
|
+ new_cxt = aa_alloc_task_context(GFP_KERNEL);
|
|
+ if (!new_cxt)
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+ }
|
|
+
|
|
+ cxt = lock_task_and_profiles(task, profile);
|
|
+ if (unlikely(profile && profile->isstale)) {
|
|
+ task_unlock(task);
|
|
+ unlock_both_profiles(profile, cxt ? cxt->profile : NULL);
|
|
+ aa_free_task_context(new_cxt);
|
|
+ return ERR_PTR(-ESTALE);
|
|
+ }
|
|
+
|
|
+ if ((current->ptrace & PT_PTRACED) && aa_may_ptrace(cxt, profile)) {
|
|
+ task_unlock(task);
|
|
+ unlock_both_profiles(profile, cxt ? cxt->profile : NULL);
|
|
+ aa_free_task_context(new_cxt);
|
|
+ return ERR_PTR(-EPERM);
|
|
+ }
|
|
+
|
|
+ if (cxt)
|
|
+ old_profile = aa_dup_profile(cxt->profile);
|
|
+ aa_change_task_context(task, new_cxt, profile, 0, NULL);
|
|
+
|
|
+ task_unlock(task);
|
|
+ unlock_both_profiles(profile, old_profile);
|
|
+ return old_profile;
|
|
+}
|
|
+
|
|
+/**
|
|
+ * lock_task_and_profiles - lock the task and confining profiles and @profile
|
|
+ * @task: task to lock
|
|
+ * @profile: extra profile to lock in addition to the current profile
|
|
+ *
|
|
+ * Handle the spinning on locking to make sure the task context and
|
|
+ * profile are consistent once all locks are aquired.
|
|
+ *
|
|
+ * return the aa_task_context currently confining the task. The task lock
|
|
+ * will be held whether or not the task is confined.
|
|
+ */
|
|
+struct aa_task_context *
|
|
+lock_task_and_profiles(struct task_struct *task, struct aa_profile *profile)
|
|
+{
|
|
+ struct aa_task_context *cxt;
|
|
+ struct aa_profile *old_profile = NULL;
|
|
+
|
|
+ rcu_read_lock();
|
|
+repeat:
|
|
+ cxt = aa_task_context(task);
|
|
+ if (cxt)
|
|
+ old_profile = cxt->profile;
|
|
+
|
|
+ lock_both_profiles(profile, old_profile);
|
|
+ task_lock(task);
|
|
+
|
|
+ /* check for race with profile transition, replacement or removal */
|
|
+ if (unlikely(cxt != aa_task_context(task))) {
|
|
+ task_unlock(task);
|
|
+ unlock_both_profiles(profile, old_profile);
|
|
+ old_profile = NULL;
|
|
+ goto repeat;
|
|
+ }
|
|
+ rcu_read_unlock();
|
|
+ return cxt;
|
|
+}
|
|
+
|
|
+static void free_aa_task_context_rcu_callback(struct rcu_head *head)
|
|
+{
|
|
+ struct aa_task_context *cxt;
|
|
+
|
|
+ cxt = container_of(head, struct aa_task_context, rcu);
|
|
+ aa_free_task_context(cxt);
|
|
+}
|
|
+
|
|
+/**
|
|
+ * aa_change_task_context - switch a task to use a new context and profile
|
|
+ * @task: task that is having its task context changed
|
|
+ * @new_cxt: new task context to use after the switch
|
|
+ * @profile: new profile to use after the switch
|
|
+ * @cookie: magic value to switch to
|
|
+ * @previous_profile: profile the task can return to
|
|
+ */
|
|
+void aa_change_task_context(struct task_struct *task,
|
|
+ struct aa_task_context *new_cxt,
|
|
+ struct aa_profile *profile, u64 cookie,
|
|
+ struct aa_profile *previous_profile)
|
|
+{
|
|
+ struct aa_task_context *old_cxt = aa_task_context(task);
|
|
+
|
|
+ if (old_cxt) {
|
|
+ list_del_init(&old_cxt->list);
|
|
+ call_rcu(&old_cxt->rcu, free_aa_task_context_rcu_callback);
|
|
+ }
|
|
+ if (new_cxt) {
|
|
+ /* set the caps_logged cache to the quiet_caps mask
|
|
+ * this has the effect of quieting caps that are not
|
|
+ * supposed to be logged
|
|
+ */
|
|
+ new_cxt->caps_logged = profile->quiet_caps;
|
|
+ new_cxt->cookie = cookie;
|
|
+ new_cxt->task = task;
|
|
+ new_cxt->profile = aa_dup_profile(profile);
|
|
+ new_cxt->previous_profile = aa_dup_profile(previous_profile);
|
|
+ list_move(&new_cxt->list, &profile->task_contexts);
|
|
+ }
|
|
+ rcu_assign_pointer(task->security, new_cxt);
|
|
+}
|