linux-toradex.git/security/security.c, branch v4.4-rc6

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2015-09-08T19:41:25+00:00

Pull security subsystem updates from James Morris:
 "Highlights:

   - PKCS#7 support added to support signed kexec, also utilized for
     module signing.  See comments in 3f1e1bea.

     ** NOTE: this requires linking against the OpenSSL library, which
        must be installed, e.g.  the openssl-devel on Fedora **

   - Smack
      - add IPv6 host labeling; ignore labels on kernel threads
      - support smack labeling mounts which use binary mount data

   - SELinux:
      - add ioctl whitelisting (see
        http://kernsec.org/files/lss2015/vanderstoep.pdf)
      - fix mprotect PROT_EXEC regression caused by mm change

   - Seccomp:
      - add ptrace options for suspend/resume"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (57 commits)
  PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them
  Documentation/Changes: Now need OpenSSL devel packages for module signing
  scripts: add extract-cert and sign-file to .gitignore
  modsign: Handle signing key in source tree
  modsign: Use if_changed rule for extracting cert from module signing key
  Move certificate handling to its own directory
  sign-file: Fix warning about BIO_reset() return value
  PKCS#7: Add MODULE_LICENSE() to test module
  Smack - Fix build error with bringup unconfigured
  sign-file: Document dependency on OpenSSL devel libraries
  PKCS#7: Appropriately restrict authenticated attributes and content type
  KEYS: Add a name for PKEY_ID_PKCS7
  PKCS#7: Improve and export the X.509 ASN.1 time object decoder
  modsign: Use extract-cert to process CONFIG_SYSTEM_TRUSTED_KEYS
  extract-cert: Cope with multiple X.509 certificates in a single file
  sign-file: Generate CMS message as signature instead of PKCS#7
  PKCS#7: Support CMS messages also [RFC5652]
  X.509: Change recorded SKID & AKID to not include Subject or Issuer
  PKCS#7: Check content type and versions
  MAINTAINERS: The keyrings mailing list has moved
  ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2015-09-01T23:13:25+00:00

Pull user namespace updates from Eric Biederman:
 "This finishes up the changes to ensure proc and sysfs do not start
  implementing executable files, as the there are application today that
  are only secure because such files do not exist.

  It akso fixes a long standing misfeature of /proc//mountinfo that
  did not show the proper source for files bind mounted from
  /proc//ns/*.

  It also straightens out the handling of clone flags related to user
  namespaces, fixing an unnecessary failure of unshare(CLONE_NEWUSER)
  when files such as /proc//environ are read while  is calling
  unshare.  This winds up fixing a minor bug in unshare flag handling
  that dates back to the first version of unshare in the kernel.

  Finally, this fixes a minor regression caused by the introduction of
  sysfs_create_mount_point, which broke someone's in house application,
  by restoring the size of /sys/fs/cgroup to 0 bytes.  Apparently that
  application uses the directory size to determine if a tmpfs is mounted
  on /sys/fs/cgroup.

  The bind mount escape fixes are present in Al Viros for-next branch.
  and I expect them to come from there.  The bind mount escape is the
  last of the user namespace related security bugs that I am aware of"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  fs: Set the size of empty dirs to 0.
  userns,pidns: Force thread group sharing, not signal handler sharing.
  unshare: Unsharing a thread does not require unsharing a vm
  nsfs: Add a show_path method to fix mountinfo
  mnt: fs_fully_visible enforce noexec and nosuid  if !SB_I_NOEXEC
  vfs: Commit to never having exectuables on proc and sysfs.

LSM: restore certain default error codes

2015-08-25T23:46:50+00:00

While in most cases commit b1d9e6b064 ("LSM: Switch to lists of hooks")
retained previous error returns, in three cases it altered them without
any explanation in the commit message. Restore all of them - in the
security_old_inode_init_security() case this led to reiserfs using
uninitialized data, sooner or later crashing the system (the only other
user of this function - ocfs2 - was unaffected afaict, since it passes
pre-initialized structures).

Signed-off-by: Jan Beulich 
Signed-off-by: Casey Schaufler 
Signed-off-by: James Morris

Yama: remove needless CONFIG_SECURITY_YAMA_STACKED

2015-07-28T03:18:19+00:00

Now that minor LSMs can cleanly stack with major LSMs, remove the unneeded
config for Yama to be made to explicitly stack. Just selecting the main
Yama CONFIG will allow it to work, regardless of the major LSM. Since
distros using Yama are already forcing it to stack, this is effectively
a no-op change.

Additionally add MAINTAINERS entry.

Signed-off-by: Kees Cook 
Signed-off-by: James Morris

vfs: Commit to never having exectuables on proc and sysfs.

2015-07-10T15:39:25+00:00

Today proc and sysfs do not contain any executable files.  Several
applications today mount proc or sysfs without noexec and nosuid and
then depend on there being no exectuables files on proc or sysfs.
Having any executable files show on proc or sysfs would cause
a user space visible regression, and most likely security problems.

Therefore commit to never allowing executables on proc and sysfs by
adding a new flag to mark them as filesystems without executables and
enforce that flag.

Test the flag where MNT_NOEXEC is tested today, so that the only user
visible effect will be that exectuables will be treated as if the
execute bit is cleared.

The filesystems proc and sysfs do not currently incoporate any
executable files so this does not result in any user visible effects.

This makes it unnecessary to vet changes to proc and sysfs tightly for
adding exectuable files or changes to chattr that would modify
existing files, as no matter what the individual file say they will
not be treated as exectuable files by the vfs.

Not having to vet changes to closely is important as without this we
are only one proc_create call (or another goof up in the
implementation of notify_change) from having problematic executables
on proc.  Those mistakes are all too easy to make and would create
a situation where there are security issues or the assumptions of
some program having to be broken (and cause userspace regressions).

Signed-off-by: "Eric W. Biederman"

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2015-06-27T20:26:03+00:00

Pull security subsystem updates from James Morris:
 "The main change in this kernel is Casey's generalized LSM stacking
  work, which removes the hard-coding of Capabilities and Yama stacking,
  allowing multiple arbitrary "small" LSMs to be stacked with a default
  monolithic module (e.g.  SELinux, Smack, AppArmor).

  See
        https://lwn.net/Articles/636056/

  This will allow smaller, simpler LSMs to be incorporated into the
  mainline kernel and arbitrarily stacked by users.  Also, this is a
  useful cleanup of the LSM code in its own right"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
  tpm, tpm_crb: fix le64_to_cpu conversions in crb_acpi_add()
  vTPM: set virtual device before passing to ibmvtpm_reset_crq
  tpm_ibmvtpm: remove unneccessary message level.
  ima: update builtin policies
  ima: extend "mask" policy matching support
  ima: add support for new "euid" policy condition
  ima: fix ima_show_template_data_ascii()
  Smack: freeing an error pointer in smk_write_revoke_subj()
  selinux: fix setting of security labels on NFS
  selinux: Remove unused permission definitions
  selinux: enable genfscon labeling for sysfs and pstore files
  selinux: enable per-file labeling for debugfs files.
  selinux: update netlink socket classes
  signals: don't abuse __flush_signals() in selinux_bprm_committed_creds()
  selinux: Print 'sclass' as string when unrecognized netlink message occurs
  Smack: allow multiple labels in onlycap
  Smack: fix seq operations in smackfs
  ima: pass iint to ima_add_violation()
  ima: wrap event related data to the new ima_event_data structure
  integrity: add validity checks for 'path' parameter
  ...

LSM: Switch to lists of hooks

2015-05-12T05:00:41+00:00

Instead of using a vector of security operations
with explicit, special case stacking of the capability
and yama hooks use lists of hooks with capability and
yama hooks included as appropriate.

The security_operations structure is no longer required.
Instead, there is a union of the function pointers that
allows all the hooks lists to use a common mechanism for
list management while retaining typing. Each module
supplies an array describing the hooks it provides instead
of a sparsely populated security_operations structure.
The description includes the element that gets put on
the hook list, avoiding the issues surrounding individual
element allocation.

The method for registering security modules is changed to
reflect the information available. The method for removing
a module, currently only used by SELinux, has also changed.
It should be generic now, however if there are potential
race conditions based on ordering of hook removal that needs
to be addressed by the calling module.

The security hooks are called from the lists and the first
failure is returned.

Signed-off-by: Casey Schaufler 
Acked-by: John Johansen 
Acked-by: Kees Cook 
Acked-by: Paul Moore 
Acked-by:  Stephen Smalley 
Acked-by: Tetsuo Handa 
Signed-off-by: James Morris

LSM: Introduce security hook calling Macros

2015-05-12T05:00:30+00:00

Introduce two macros around calling the functions in the
security operations vector. The marco versions here do not
change any behavior.

Signed-off-by: Casey Schaufler 
Acked-by: John Johansen 
Acked-by: Kees Cook 
Acked-by: Paul Moore 
Acked-by:  Stephen Smalley 
Acked-by: Tetsuo Handa 
Signed-off-by: James Morris

LSM: Split security.h

2015-05-12T05:00:16+00:00

The security.h header file serves two purposes,
interfaces for users of the security modules and
interfaces for security modules. Users of the
security modules don't need to know about what's
in the security_operations structure, so pull it
out into it's own header, lsm_hooks.h

Signed-off-by: Casey Schaufler 
Acked-by: John Johansen 
Acked-by: Kees Cook 
Acked-by: Paul Moore 
Acked-by:  Stephen Smalley 
Acked-by: Tetsuo Handa 
Signed-off-by: James Morris

security: make inode_follow_link RCU-walk aware

2015-05-11T12:13:11+00:00

inode_follow_link now takes an inode and rcu flag as well as the
dentry.

inode is used in preference to d_backing_inode(dentry), particularly
in RCU-walk mode.

selinux_inode_follow_link() gets dentry_has_perm() and
inode_has_perm() open-coded into it so that it can call
avc_has_perm_flags() in way that is safe if LOOKUP_RCU is set.

Calling avc_has_perm_flags() with rcu_read_lock() held means
that when avc_has_perm_noaudit calls avc_compute_av(), the attempt
to rcu_read_unlock() before calling security_compute_av() will not
actually drop the RCU read-lock.

However as security_compute_av() is completely in a read_lock()ed
region, it should be safe with the RCU read-lock held.

Signed-off-by: NeilBrown 
Signed-off-by: Al Viro