* License.
*/
+#include <linux/tty.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+
#include "include/apparmor.h"
#include "include/audit.h"
+#include "include/context.h"
#include "include/file.h"
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"
+#include "include/label.h"
-struct file_perms nullperms;
+static u32 map_mask_to_chr_mask(u32 mask)
+{
+ u32 m = mask & PERMS_CHRS_MASK;
+ if (mask & AA_MAY_GETATTR)
+ m |= MAY_READ;
+ if (mask & (AA_MAY_SETATTR | AA_MAY_CHMOD | AA_MAY_CHOWN))
+ m |= MAY_WRITE;
+
+ return m;
+}
/**
* audit_file_mask - convert mask to permission string
{
char str[10];
- char *m = str;
-
- if (mask & AA_EXEC_MMAP)
- *m++ = 'm';
- if (mask & (MAY_READ | AA_MAY_META_READ))
- *m++ = 'r';
- if (mask & (MAY_WRITE | AA_MAY_META_WRITE | AA_MAY_CHMOD |
- AA_MAY_CHOWN))
- *m++ = 'w';
- else if (mask & MAY_APPEND)
- *m++ = 'a';
- if (mask & AA_MAY_CREATE)
- *m++ = 'c';
- if (mask & AA_MAY_DELETE)
- *m++ = 'd';
- if (mask & AA_MAY_LINK)
- *m++ = 'l';
- if (mask & AA_MAY_LOCK)
- *m++ = 'k';
- if (mask & MAY_EXEC)
- *m++ = 'x';
- *m = '\0';
-
+ aa_perm_mask_to_str(str, aa_file_perm_chrs, map_mask_to_chr_mask(mask));
audit_log_string(ab, str);
}
struct common_audit_data *sa = va;
kuid_t fsuid = current_fsuid();
- if (aad(sa)->fs.request & AA_AUDIT_FILE_MASK) {
+ if (aad(sa)->request & AA_AUDIT_FILE_MASK) {
audit_log_format(ab, " requested_mask=");
- audit_file_mask(ab, aad(sa)->fs.request);
+ audit_file_mask(ab, aad(sa)->request);
}
- if (aad(sa)->fs.denied & AA_AUDIT_FILE_MASK) {
+ if (aad(sa)->denied & AA_AUDIT_FILE_MASK) {
audit_log_format(ab, " denied_mask=");
- audit_file_mask(ab, aad(sa)->fs.denied);
+ audit_file_mask(ab, aad(sa)->denied);
}
- if (aad(sa)->fs.request & AA_AUDIT_FILE_MASK) {
+ if (aad(sa)->request & AA_AUDIT_FILE_MASK) {
audit_log_format(ab, " fsuid=%d",
from_kuid(&init_user_ns, fsuid));
audit_log_format(ab, " ouid=%d",
from_kuid(&init_user_ns, aad(sa)->fs.ouid));
}
- if (aad(sa)->fs.target) {
+ if (aad(sa)->peer) {
+ audit_log_format(ab, " target=");
+ aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+ FLAG_VIEW_SUBNS, GFP_ATOMIC);
+ } else if (aad(sa)->fs.target) {
audit_log_format(ab, " target=");
audit_log_untrustedstring(ab, aad(sa)->fs.target);
}
* aa_audit_file - handle the auditing of file operations
* @profile: the profile being enforced (NOT NULL)
* @perms: the permissions computed for the request (NOT NULL)
- * @gfp: allocation flags
* @op: operation being mediated
* @request: permissions requested
* @name: name of object being mediated (MAYBE NULL)
* @target: name of target (MAYBE NULL)
+ * @tlabel: target label (MAY BE NULL)
* @ouid: object uid
* @info: extra information message (MAYBE NULL)
* @error: 0 if operation allowed else failure error code
*
* Returns: %0 or error on failure
*/
-int aa_audit_file(struct aa_profile *profile, struct file_perms *perms,
+int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms,
const char *op, u32 request, const char *name,
- const char *target, kuid_t ouid, const char *info, int error)
+ const char *target, struct aa_label *tlabel,
+ kuid_t ouid, const char *info, int error)
{
int type = AUDIT_APPARMOR_AUTO;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_TASK, op);
sa.u.tsk = NULL;
- aad(&sa)->fs.request = request;
+ aad(&sa)->request = request;
aad(&sa)->name = name;
aad(&sa)->fs.target = target;
+ aad(&sa)->peer = tlabel;
aad(&sa)->fs.ouid = ouid;
aad(&sa)->info = info;
aad(&sa)->error = error;
mask = 0xffff;
/* mask off perms that are not being force audited */
- aad(&sa)->fs.request &= mask;
+ aad(&sa)->request &= mask;
- if (likely(!aad(&sa)->fs.request))
+ if (likely(!aad(&sa)->request))
return 0;
type = AUDIT_APPARMOR_AUDIT;
} else {
/* only report permissions that were denied */
- aad(&sa)->fs.request = aad(&sa)->fs.request & ~perms->allow;
- AA_BUG(!aad(&sa)->fs.request);
+ aad(&sa)->request = aad(&sa)->request & ~perms->allow;
+ AA_BUG(!aad(&sa)->request);
- if (aad(&sa)->fs.request & perms->kill)
+ if (aad(&sa)->request & perms->kill)
type = AUDIT_APPARMOR_KILL;
/* quiet known rejects, assumes quiet and kill do not overlap */
- if ((aad(&sa)->fs.request & perms->quiet) &&
+ if ((aad(&sa)->request & perms->quiet) &&
AUDIT_MODE(profile) != AUDIT_NOQUIET &&
AUDIT_MODE(profile) != AUDIT_ALL)
- aad(&sa)->fs.request &= ~perms->quiet;
+ aad(&sa)->request &= ~perms->quiet;
- if (!aad(&sa)->fs.request)
- return COMPLAIN_MODE(profile) ? 0 : aad(&sa)->error;
+ if (!aad(&sa)->request)
+ return aad(&sa)->error;
}
- aad(&sa)->fs.denied = aad(&sa)->fs.request & ~perms->allow;
+ aad(&sa)->denied = aad(&sa)->request & ~perms->allow;
return aa_audit(type, profile, &sa, file_audit_cb);
}
+/**
+ * is_deleted - test if a file has been completely unlinked
+ * @dentry: dentry of file to test for deletion (NOT NULL)
+ *
+ * Returns: %1 if deleted else %0
+ */
+static inline bool is_deleted(struct dentry *dentry)
+{
+ if (d_unlinked(dentry) && d_backing_inode(dentry)->i_nlink == 0)
+ return 1;
+ return 0;
+}
+
+static int path_name(const char *op, struct aa_label *label,
+ const struct path *path, int flags, char *buffer,
+ const char **name, struct path_cond *cond, u32 request)
+{
+ struct aa_profile *profile;
+ const char *info = NULL;
+ int error;
+
+ error = aa_path_name(path, flags, buffer, name, &info,
+ labels_profile(label)->disconnected);
+ if (error) {
+ fn_for_each_confined(label, profile,
+ aa_audit_file(profile, &nullperms, op, request, *name,
+ NULL, NULL, cond->uid, info, error));
+ return error;
+ }
+
+ return 0;
+}
+
/**
* map_old_perms - map old file perms layout to the new layout
* @old: permission set in old mapping
{
u32 new = old & 0xf;
if (old & MAY_READ)
- new |= AA_MAY_META_READ;
+ new |= AA_MAY_GETATTR | AA_MAY_OPEN;
if (old & MAY_WRITE)
- new |= AA_MAY_META_WRITE | AA_MAY_CREATE | AA_MAY_DELETE |
- AA_MAY_CHMOD | AA_MAY_CHOWN;
+ new |= AA_MAY_SETATTR | AA_MAY_CREATE | AA_MAY_DELETE |
+ AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_OPEN;
if (old & 0x10)
new |= AA_MAY_LINK;
/* the old mapping lock and link_subset flags where overlaid
}
/**
- * compute_perms - convert dfa compressed perms to internal perms
+ * aa_compute_fperms - convert dfa compressed perms to internal perms
* @dfa: dfa to compute perms for (NOT NULL)
* @state: state in dfa
* @cond: conditions to consider (NOT NULL)
*
* Returns: computed permission set
*/
-static struct file_perms compute_perms(struct aa_dfa *dfa, unsigned int state,
- struct path_cond *cond)
+struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state,
+ struct path_cond *cond)
{
- struct file_perms perms;
+ struct aa_perms perms;
/* FIXME: change over to new dfa format
* currently file perms are encoded in the dfa, new format
* splits the permissions from the dfa. This mapping can be
* done at profile load
*/
- perms.kill = 0;
+ perms.deny = 0;
+ perms.kill = perms.stop = 0;
+ perms.complain = perms.cond = 0;
+ perms.hide = 0;
+ perms.prompt = 0;
if (uid_eq(current_fsuid(), cond->uid)) {
perms.allow = map_old_perms(dfa_user_allow(dfa, state));
perms.quiet = map_old_perms(dfa_other_quiet(dfa, state));
perms.xindex = dfa_other_xindex(dfa, state);
}
- perms.allow |= AA_MAY_META_READ;
+ perms.allow |= AA_MAY_GETATTR;
/* change_profile wasn't determined by ownership in old mapping */
if (ACCEPT_TABLE(dfa)[state] & 0x80000000)
*/
unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start,
const char *name, struct path_cond *cond,
- struct file_perms *perms)
+ struct aa_perms *perms)
{
unsigned int state;
- if (!dfa) {
- *perms = nullperms;
- return DFA_NOMATCH;
- }
-
state = aa_dfa_match(dfa, start, name);
- *perms = compute_perms(dfa, state, cond);
+ *perms = aa_compute_fperms(dfa, state, cond);
return state;
}
-/**
- * is_deleted - test if a file has been completely unlinked
- * @dentry: dentry of file to test for deletion (NOT NULL)
- *
- * Returns: %1 if deleted else %0
- */
-static inline bool is_deleted(struct dentry *dentry)
+int __aa_path_perm(const char *op, struct aa_profile *profile, const char *name,
+ u32 request, struct path_cond *cond, int flags,
+ struct aa_perms *perms)
{
- if (d_unlinked(dentry) && d_backing_inode(dentry)->i_nlink == 0)
- return 1;
- return 0;
+ int e = 0;
+
+ if (profile_unconfined(profile))
+ return 0;
+ aa_str_perms(profile->file.dfa, profile->file.start, name, cond, perms);
+ if (request & ~perms->allow)
+ e = -EACCES;
+ return aa_audit_file(profile, perms, op, request, name, NULL, NULL,
+ cond->uid, NULL, e);
+}
+
+
+static int profile_path_perm(const char *op, struct aa_profile *profile,
+ const struct path *path, char *buffer, u32 request,
+ struct path_cond *cond, int flags,
+ struct aa_perms *perms)
+{
+ const char *name;
+ int error;
+
+ if (profile_unconfined(profile))
+ return 0;
+
+ error = path_name(op, &profile->label, path,
+ flags | profile->path_flags, buffer, &name, cond,
+ request);
+ if (error)
+ return error;
+ return __aa_path_perm(op, profile, name, request, cond, flags,
+ perms);
}
/**
* aa_path_perm - do permissions check & audit for @path
* @op: operation being checked
- * @profile: profile being enforced (NOT NULL)
+ * @label: profile being enforced (NOT NULL)
* @path: path to check permissions of (NOT NULL)
* @flags: any additional path flags beyond what the profile specifies
* @request: requested permissions
*
* Returns: %0 else error if access denied or other error
*/
-int aa_path_perm(const char *op, struct aa_profile *profile,
+int aa_path_perm(const char *op, struct aa_label *label,
const struct path *path, int flags, u32 request,
struct path_cond *cond)
{
+ struct aa_perms perms = {};
+ struct aa_profile *profile;
char *buffer = NULL;
- struct file_perms perms = {};
- const char *name, *info = NULL;
int error;
- flags |= profile->path_flags | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0);
- error = aa_path_name(path, flags, &buffer, &name, &info);
- if (error) {
- if (error == -ENOENT && is_deleted(path->dentry)) {
- /* Access to open files that are deleted are
- * give a pass (implicit delegation)
- */
- error = 0;
- info = NULL;
- perms.allow = request;
- }
- } else {
- aa_str_perms(profile->file.dfa, profile->file.start, name, cond,
- &perms);
- if (request & ~perms.allow)
- error = -EACCES;
- }
- error = aa_audit_file(profile, &perms, op, request, name, NULL,
- cond->uid, info, error);
- kfree(buffer);
+ flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
+ 0);
+ get_buffers(buffer);
+ error = fn_for_each_confined(label, profile,
+ profile_path_perm(op, profile, path, buffer, request,
+ cond, flags, &perms));
+
+ put_buffers(buffer);
return error;
}
};
char *buffer = NULL, *buffer2 = NULL;
const char *lname, *tname = NULL, *info = NULL;
- struct file_perms lperms, perms;
+ struct aa_perms lperms, perms;
u32 request = AA_MAY_LINK;
unsigned int state;
int error;
+ get_buffers(buffer, buffer2);
lperms = nullperms;
/* buffer freed below, lname is pointer in buffer */
- error = aa_path_name(&link, profile->path_flags, &buffer, &lname,
- &info);
+ error = aa_path_name(&link, profile->path_flags, buffer, &lname,
+ &info, profile->disconnected);
if (error)
goto audit;
/* buffer2 freed below, tname is pointer in buffer2 */
- error = aa_path_name(&target, profile->path_flags, &buffer2, &tname,
- &info);
+ error = aa_path_name(&target, profile->path_flags, buffer2, &tname,
+ &info, profile->disconnected);
if (error)
goto audit;
audit:
error = aa_audit_file(profile, &lperms, OP_LINK, request,
- lname, tname, cond.uid, info, error);
- kfree(buffer);
- kfree(buffer2);
+ lname, tname, NULL, cond.uid, info, error);
+ put_buffers(buffer, buffer2);
return error;
}
/**
* aa_file_perm - do permission revalidation check & audit for @file
* @op: operation being checked
- * @profile: profile being enforced (NOT NULL)
+ * @label: label being enforced (NOT NULL)
* @file: file to revalidate access permissions on (NOT NULL)
* @request: requested permissions
*
* Returns: %0 if access allowed else error
*/
-int aa_file_perm(const char *op, struct aa_profile *profile, struct file *file,
+int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
u32 request)
{
struct path_cond cond = {
.uid = file_inode(file)->i_uid,
.mode = file_inode(file)->i_mode
};
+ struct aa_file_ctx *fctx;
+ struct aa_label *flabel;
+ u32 denied;
+ int error = 0;
+
+ AA_BUG(!label);
+ AA_BUG(!file);
+
+ fctx = file_ctx(file);
+
+ rcu_read_lock();
+ flabel = rcu_dereference(fctx->label);
+ AA_BUG(!flabel);
+
+ /* revalidate access, if task is unconfined, or the cached cred
+ * doesn't match or if the request is for more permissions than
+ * was granted.
+ *
+ * Note: the test for !unconfined(flabel) is to handle file
+ * delegation from unconfined tasks
+ */
+ denied = request & ~fctx->allow;
+ if (unconfined(label) || unconfined(flabel) ||
+ (!denied && aa_label_is_subset(flabel, label)))
+ goto done;
- return aa_path_perm(op, profile, &file->f_path, PATH_DELEGATE_DELETED,
- request, &cond);
+ /* TODO: label cross check */
+
+ if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry))
+ error = aa_path_perm(op, label, &file->f_path,
+ PATH_DELEGATE_DELETED, request, &cond);
+
+done:
+ rcu_read_unlock();
+
+ return error;
+}
+
+static void revalidate_tty(struct aa_label *label)
+{
+ struct tty_struct *tty;
+ int drop_tty = 0;
+
+ tty = get_current_tty();
+ if (!tty)
+ return;
+
+ spin_lock(&tty->files_lock);
+ if (!list_empty(&tty->tty_files)) {
+ struct tty_file_private *file_priv;
+ struct file *file;
+ /* TODO: Revalidate access to controlling tty. */
+ file_priv = list_first_entry(&tty->tty_files,
+ struct tty_file_private, list);
+ file = file_priv->file;
+
+ if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE))
+ drop_tty = 1;
+ }
+ spin_unlock(&tty->files_lock);
+ tty_kref_put(tty);
+
+ if (drop_tty)
+ no_tty();
+}
+
+static int match_file(const void *p, struct file *file, unsigned int fd)
+{
+ struct aa_label *label = (struct aa_label *)p;
+
+ if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file)))
+ return fd + 1;
+ return 0;
+}
+
+
+/* based on selinux's flush_unauthorized_files */
+void aa_inherit_files(const struct cred *cred, struct files_struct *files)
+{
+ struct aa_label *label = aa_get_newest_cred_label(cred);
+ struct file *devnull = NULL;
+ unsigned int n;
+
+ revalidate_tty(label);
+
+ /* Revalidate access to inherited open files. */
+ n = iterate_fd(files, 0, match_file, label);
+ if (!n) /* none found? */
+ goto out;
+
+ devnull = dentry_open(&aa_null, O_RDWR, cred);
+ if (IS_ERR(devnull))
+ devnull = NULL;
+ /* replace all the matching ones with this */
+ do {
+ replace_fd(n - 1, devnull, 0);
+ } while ((n = iterate_fd(files, n, match_file, label)) != 0);
+ if (devnull)
+ fput(devnull);
+out:
+ aa_put_label(label);
}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff