I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.
Unchanged from previous versions except for being updated
to the latest security next branch.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
As reported by yangshukui, a permission denial from security_task_wait()
can lead to a soft lockup in zap_pid_ns_processes() since it only expects
sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can
in general lead to zombies; in the absence of some way to automatically
reparent a child process upon a denial, the hook is not useful. Remove
the security hook and its implementations in SELinux and Smack. Smack
already removed its check from its hook.
Reported-by: yangshukui <yangshukui@huawei.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Processes can only alter their own security attributes via
/proc/pid/attr nodes. This is presently enforced by each individual
security module and is also imposed by the Linux credentials
implementation, which only allows a task to alter its own credentials.
Move the check enforcing this restriction from the individual
security modules to proc_pid_attr_write() before calling the security hook,
and drop the unnecessary task argument to the security hook since it can
only ever be the current task.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
During a new file creation we need to make sure new file is created with the
right label. New file is created in upper/ so effectively file should get
label as if task had created file in upper/.
We switched to mounter's creds for actual file creation. Also if there is a
whiteout present, then file will be created in work/ dir first and then
renamed in upper. In none of the cases file will be labeled as we want it to
be.
This patch introduces a new hook dentry_create_files_as(), which determines
the label/context dentry will get if it had been created by task in upper
and modify passed set of creds appropriately. Caller makes use of these new
creds for file creation.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: fix whitespace issues found with checkpatch.pl]
[PM: changes to use stat->mode in ovl_create_or_link()]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Provide a security hook which is called when xattrs of a file are being
copied up. This hook is called once for each xattr and LSM can return
0 if the security module wants the xattr to be copied up, 1 if the
security module wants the xattr to be discarded on the copy, -EOPNOTSUPP
if the security module does not handle/manage the xattr, or a -errno
upon an error.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: whitespace cleanup for checkpatch.pl]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Provide a security hook to label new file correctly when a file is copied
up from lower layer to upper layer of a overlay/union mount.
This hook can prepare a new set of creds which are suitable for new file
creation during copy up. Caller will use new creds to create file and then
revert back to old creds and release new creds.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: whitespace cleanup to appease checkpatch.pl]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull security subsystem updates from James Morris:
"Highlights:
- A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
of modules and firmware to be loaded from a specific device (this
is from ChromeOS, where the device as a whole is verified
cryptographically via dm-verity).
This is disabled by default but can be configured to be enabled by
default (don't do this if you don't know what you're doing).
- Keys: allow authentication data to be stored in an asymmetric key.
Lots of general fixes and updates.
- SELinux: add restrictions for loading of kernel modules via
finit_module(). Distinguish non-init user namespace capability
checks. Apply execstack check on thread stacks"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
LSM: LoadPin: provide enablement CONFIG
Yama: use atomic allocations when reporting
seccomp: Fix comment typo
ima: add support for creating files using the mknodat syscall
ima: fix ima_inode_post_setattr
vfs: forbid write access when reading a file into memory
fs: fix over-zealous use of "const"
selinux: apply execstack check on thread stacks
selinux: distinguish non-init user namespace capability checks
LSM: LoadPin for kernel file loading restrictions
fs: define a string representation of the kernel_read_file_id enumeration
Yama: consolidate error reporting
string_helpers: add kstrdup_quotable_file
string_helpers: add kstrdup_quotable_cmdline
string_helpers: add kstrdup_quotable
selinux: check ss_initialized before revalidating an inode label
selinux: delay inode label lookup as long as possible
selinux: don't revalidate an inode's label when explicitly setting it
selinux: Change bool variable name to index.
KEYS: Add KEYCTL_DH_COMPUTE command
...
Pull 'struct path' constification update from Al Viro:
"'struct path' is passed by reference to a bunch of Linux security
methods; in theory, there's nothing to stop them from modifying the
damn thing and LSM community being what it is, sooner or later some
enterprising soul is going to decide that it's a good idea.
Let's remove the temptation and constify all of those..."
* 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
constify ima_d_path()
constify security_sb_pivotroot()
constify security_path_chroot()
constify security_path_{link,rename}
apparmor: remove useless checks for NULL ->mnt
constify security_path_{mkdir,mknod,symlink}
constify security_path_{unlink,rmdir}
apparmor: constify common_perm_...()
apparmor: constify aa_path_link()
apparmor: new helper - common_path_perm()
constify chmod_common/security_path_chmod
constify security_sb_mount()
constify chown_common/security_path_chown
tomoyo: constify assorted struct path *
apparmor_path_truncate(): path->mnt is never NULL
constify vfs_truncate()
constify security_path_truncate()
[apparmor] constify struct path * in a bunch of helpers
security_settime() uses a timespec, which is not year 2038 safe
on 32bit systems. Thus this patch introduces the security_settime64()
function with timespec64 type. We also convert the cap_settime() helper
function to use the 64bit types.
This patch then moves security_settime() to the header file as an
inline helper function so that existing users can be iteratively
converted.
None of the existing hooks is using the timespec argument and therefor
the patch is not making any functional changes.
Cc: Serge Hallyn <serge.hallyn@canonical.com>,
Cc: James Morris <james.l.morris@oracle.com>,
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Cc: Paul Moore <pmoore@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Kees Cook <keescook@chromium.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
[jstultz: Reworded commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
This LSM enforces that kernel-loaded files (modules, firmware, etc)
must all come from the same filesystem, with the expectation that
such a filesystem is backed by a read-only device such as dm-verity
or CDROM. This allows systems that have a verified and/or unchangeable
filesystem to enforce module and firmware loading restrictions without
needing to sign the files individually.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The skb_owned_by hook was added with the commit ca10b9e9a8
("selinux: add a skb_owned_by() hook") and later removed
when said commit was reverted.
Later on, when switching to list of hooks, a field named
'skb_owned_by' was included into the security_hook_head struct,
but without any users nor caller.
This commit removes the said left-over field.
Fixes: b1d9e6b064 ("LSM: Switch to lists of hooks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Paul Moore <pmoore@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Replace copy_module_from_fd() with kernel_read_file_from_fd().
Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.
The security function security_kernel_module_from_file() was called prior
to reading a kernel module. Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook. Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.
This patch removes the security_kernel_module_from_file() hook and security
call.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
The kernel_read_file security hook is called prior to reading the file
into memory.
Changelog v4+:
- export security_kernel_read_file()
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Replace the fw_read_file_contents with kernel_file_read_from_path().
Although none of the upstreamed LSMs define a kernel_fw_from_file hook,
IMA is called by the security function to prevent unsigned firmware from
being loaded and to measure/appraise signed firmware, based on policy.
Instead of reading the firmware twice, once for measuring/appraising the
firmware and again for reading the firmware contents into memory, the
kernel_post_read_file() security hook calculates the file hash based on
the in memory file buffer. The firmware is read once.
This patch removes the LSM kernel_fw_from_file() hook and security call.
Changelog v4+:
- revert dropped buf->size assignment - reported by Sergey Senozhatsky
v3:
- remove kernel_fw_from_file hook
- use kernel_file_read_from_path() - requested by Luis
v2:
- reordered and squashed firmware patches
- fix MAX firmware size (Kees Cook)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
To differentiate between the kernel_read_file() callers, this patch
defines a new enumeration named kernel_read_file_id and includes the
caller identifier as an argument.
Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS,
READING_FIRMWARE, READING_MODULE, and READING_POLICY.
Changelog v3:
- Replace the IMA specific enumeration with a generic one.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
For a while it was looked down upon to directly read files from Linux.
These days there exists a few mechanisms in the kernel that do just
this though to load a file into a local buffer. There are minor but
important checks differences on each. This patch set is the first
attempt at resolving some of these differences.
This patch introduces a common function for reading files from the kernel
with the corresponding security post-read hook and function.
Changelog v4+:
- export security_kernel_post_read_file() - Fengguang Wu
v3:
- additional bounds checking - Luis
v2:
- To simplify patch review, re-ordered patches
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Add a hook to invalidate an inode's security label when the cached
information becomes invalid.
Add the new hook in selinux: set a flag when a security label becomes
invalid.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Make the inode argument of the inode_getsecid hook non-const so that we
can use it to revalidate invalid security labels.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Make the inode argument of the inode_getsecurity hook non-const so that
we can use it to revalidate invalid security labels.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
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 <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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
...
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 <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Add a list header for each security hook. They aren't used until
later in the patch series. They are grouped together in a structure
so that there doesn't need to be an external address for each.
Macro-ize the initialization of the security_operations
for each security module in anticipation of changing out
the security_operations structure.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Add the large comment describing the content of the
security_operations structure to lsm_hooks.h. This
wasn't done in the previous (1/7) patch because it
would have exceeded the mail list size limits.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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 <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Casey Schaufler