This makes it possible to route the error to the appropriate
labelling engine. CALIPSO is far less verbose than CIPSO
when encountering a bogus packet, so there is no need for a
CALIPSO error handler.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The SMACK64, SMACK64EXEC, and SMACK64MMAP labels are all handled
differently in untrusted mounts. This is confusing and
potentically problematic. Change this to handle them all the same
way that SMACK64 is currently handled; that is, read the label
from disk and check it at use time. For SMACK64 and SMACK64MMAP
access is denied if the label does not match smk_root. To be
consistent with suid, a SMACK64EXEC label which does not match
smk_root will still allow execution of the file but will not run
with the label supplied in the xattr.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Security labels from unprivileged mounts cannot be trusted.
Ideally for these mounts we would assign the objects in the
filesystem the same label as the inode for the backing device
passed to mount. Unfortunately it's currently impossible to
determine which inode this is from the LSM mount hooks, so we
settle for the label of the process doing the mount.
This label is assigned to s_root, and also to smk_default to
ensure that new inodes receive this label. The transmute property
is also set on s_root to make this behavior more explicit, even
though it is technically not necessary.
If a filesystem has existing security labels, access to inodes is
permitted if the label is the same as smk_root, otherwise access
is denied. The SMACK64EXEC xattr is completely ignored.
Explicit setting of security labels continues to require
CAP_MAC_ADMIN in init_user_ns.
Altogether, this ensures that filesystem objects are not
accessible to subjects which cannot already access the backing
store, that MAC is not violated for any objects in the fileystem
which are already labeled, and that a user cannot use an
unprivileged mount to gain elevated MAC privileges.
sysfs, tmpfs, and ramfs are already mountable from user
namespaces and support security labels. We can't rule out the
possibility that these filesystems may already be used in mounts
from user namespaces with security lables set from the init
namespace, so failing to trust lables in these filesystems may
introduce regressions. It is safe to trust labels from these
filesystems, since the unprivileged user does not control the
backing store and thus cannot supply security labels, so an
explicit exception is made to trust labels from these
filesystems.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time. It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.
A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.
Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kill with signal number 0 is commonly used for checking PID existence.
Smack treated such cases like any other kills, although no signal is
actually delivered when sig == 0.
Checking permissions when sig == 0 didn't prevent an unprivileged caller
from learning whether PID exists or not. When it existed, kernel returned
EPERM, when it didn't - ESRCH. The only effect of policy check in such
case is noise in audit logs.
This change lets Smack silently ignore kill() invocations with sig == 0.
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Before this commit, removing the access property of
a file, aka, the extended attribute security.SMACK64
was not effictive until the cache had been cleaned.
This patch fixes that problem.
Signed-off-by: José Bollo <jobol@nonadev.net>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Prior to the 4.2 kernel there no no harm in providing
a security module hook that does nothing, as the default
hook would get called if the module did not supply one.
With the list based infrastructure an empty hook adds
overhead. This patch removes the three Smack hooks that
don't actually do anything.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull security subsystem updates from James Morris:
- EVM gains support for loading an x509 cert from the kernel
(EVM_LOAD_X509), into the EVM trusted kernel keyring.
- Smack implements 'file receive' process-based permission checking for
sockets, rather than just depending on inode checks.
- Misc enhancments for TPM & TPM2.
- Cleanups and bugfixes for SELinux, Keys, and IMA.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits)
selinux: Inode label revalidation performance fix
KEYS: refcount bug fix
ima: ima_write_policy() limit locking
IMA: policy can be updated zero times
selinux: rate-limit netlink message warnings in selinux_nlmsg_perm()
selinux: export validatetrans decisions
gfs2: Invalid security labels of inodes when they go invalid
selinux: Revalidate invalid inode security labels
security: Add hook to invalidate inode security labels
selinux: Add accessor functions for inode->i_security
security: Make inode argument of inode_getsecid non-const
security: Make inode argument of inode_getsecurity non-const
selinux: Remove unused variable in selinux_inode_init_security
keys, trusted: seal with a TPM2 authorization policy
keys, trusted: select hash algorithm for TPM2 chips
keys, trusted: fix: *do not* allow duplicate key options
tpm_ibmvtpm: properly handle interrupted packet receptions
tpm_tis: Tighten IRQ auto-probing
tpm_tis: Refactor the interrupt setup
tpm_tis: Get rid of the duplicate IRQ probing code
...
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
Smack security handler for sendmsg() syscall
is vulnerable to type confusion issue what
can allow to privilege escalation into root
or cause denial of service.
A malicious attacker can create socket of one
type for example AF_UNIX and pass is into
sendmsg() function ensuring that this is
AF_INET socket.
Remedy
Do not trust user supplied data.
Proposed fix below.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Signed-off-by: Mateusz Fruba <m.fruba@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Add a nfs_listxattr operation. Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The existing file receive hook checks for access on
the file inode even for UDS. This is not right, as
the inode is not used by Smack to make access checks
for sockets. This change checks for an appropriate
access relationship between the receiving (current)
process and the socket. If the process can't write
to the socket's send label or the socket's receive
label can't write to the process fail.
This will allow the legitimate cases, where the
socket sender and socket receiver can freely communicate.
Only strangly set socket labels should cause a problem.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Pull networking fixes from David Miller:
1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet.
2) Several spots need to get to the original listner for SYN-ACK
packets, most spots got this ok but some were not. Whilst covering
the remaining cases, create a helper to do this. From Eric Dumazet.
3) Missiing check of return value from alloc_netdev() in CAIF SPI code,
from Rasmus Villemoes.
4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich.
5) Use after free in mvneta driver, from Justin Maggard.
6) Fix race on dst->flags access in dst_release(), from Eric Dumazet.
7) Add missing ZLIB_INFLATE dependency for new qed driver. From Arnd
Bergmann.
8) Fix multicast getsockopt deadlock, from WANG Cong.
9) Fix deadlock in btusb, from Kuba Pawlak.
10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6
counter state. From Sabrina Dubroca.
11) Fix packet_bind() race, which can cause lost notifications, from
Francesco Ruggeri.
12) Fix MAC restoration in qlcnic driver during bonding mode changes,
from Jarod Wilson.
13) Revert bridging forward delay change which broke libvirt and other
userspace things, from Vlad Yasevich.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
Revert "bridge: Allow forward delay to be cfgd when STP enabled"
bpf_trace: Make dependent on PERF_EVENTS
qed: select ZLIB_INFLATE
net: fix a race in dst_release()
net: mvneta: Fix memory use after free.
net: Documentation: Fix default value tcp_limit_output_bytes
macvtap: Resolve possible __might_sleep warning in macvtap_do_read()
mvneta: add FIXED_PHY dependency
net: caif: check return value of alloc_netdev
net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA
drivers: net: xgene: fix RGMII 10/100Mb mode
netfilter: nft_meta: use skb_to_full_sk() helper
net_sched: em_meta: use skb_to_full_sk() helper
sched: cls_flow: use skb_to_full_sk() helper
netfilter: xt_owner: use skb_to_full_sk() helper
smack: use skb_to_full_sk() helper
net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()
bpf: doc: correct arch list for supported eBPF JIT
dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put"
bonding: fix panic on non-ARPHRD_ETHER enslave failure
...
This module wants to access sk->sk_security, which is not
available for request sockets.
Fixes: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull security subsystem update from James Morris:
"This is mostly maintenance updates across the subsystem, with a
notable update for TPM 2.0, and addition of Jarkko Sakkinen as a
maintainer of that"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits)
apparmor: clarify CRYPTO dependency
selinux: Use a kmem_cache for allocation struct file_security_struct
selinux: ioctl_has_perm should be static
selinux: use sprintf return value
selinux: use kstrdup() in security_get_bools()
selinux: use kmemdup in security_sid_to_context_core()
selinux: remove pointless cast in selinux_inode_setsecurity()
selinux: introduce security_context_str_to_sid
selinux: do not check open perm on ftruncate call
selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default
KEYS: Merge the type-specific data with the payload data
KEYS: Provide a script to extract a module signature
KEYS: Provide a script to extract the sys cert list from a vmlinux file
keys: Be more consistent in selection of union members used
certs: add .gitignore to stop git nagging about x509_certificate_list
KEYS: use kvfree() in add_key
Smack: limited capability for changing process label
TPM: remove unnecessary little endian conversion
vTPM: support little endian guests
char: Drop owner assignment from i2c_driver
...
This feature introduces new kernel interface:
- <smack_fs>/relabel-self - for setting transition labels list
This list is used to control smack label transition mechanism.
List is set by, and per process. Process can transit to new label only if
label is on the list. Only process with CAP_MAC_ADMIN capability can add
labels to this list. With this list, process can change it's label without
CAP_MAC_ADMIN but only once. After label changing, list is unset.
Changes in v2:
* use list_for_each_entry instead of _rcu during label write
* added missing description in security/Smack.txt
Changes in v3:
* squashed into one commit
Changes in v4:
* switch from global list to per-task list
* since the per-task list is accessed only by the task itself
there is no need to use synchronization mechanisms on it
Changes in v5:
* change smackfs interface of relabel-self to the one used for onlycap
multiple labels are accepted, separated by space, which
replace the previous list upon write
Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.
So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This fix writes the task label when
smack_d_instantiate is called, before the
label of the superblock was written on the
pipe's inode.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
This change has two goals:
- delay the setting of 'smack_enabled' until
it will be really effective
- ensure that smackfs is valid only if 'smack_enabled'
is set (it is already the case in smack_netfilter.c)
Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Fixes the following sparse warning:
security/smack/smack_lsm.c:55:1: warning: symbol 'smk_ipv6_port_list'
was not declared. Should it be static?
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
'commit e774ad683f ("smack: pass error code through pointers")'
made this function return proper error codes instead of NULL. Reflect that.
This is a fix for a NULL dereference introduced in
'commit 21abb1ec41 ("Smack: IPv6 host labeling")'
echo "$SOME_IPV6_ADDR \"test" > /smack/ipv6host
(this should return EINVAL, it doesn't)
cat /smack/ipv6host
(derefences 0x000a)
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Only pass the void *priv parameter out of the nf_hook_ops. That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The changes for mounting binary filesystems was allied
improperly, with the list of tokens being in an ifdef that
it shouldn't have been. Fix that, and a couple style issues
that were bothering me.
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Adds an ignore case for kernel tasks,
so that they can access all resources.
Since kernel worker threads are spawned with
floor label, they are severely restricted by
Smack policy. It is not an issue without onlycap,
as these processes also run with root,
so CAP_MAC_OVERRIDE kicks in. But with onlycap
turned on, there is no way to change the label
for these processes.
Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
The kbuild test robot reported a couple of these,
and the third showed up by inspection. Making the
symbols static is proper.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
IPv6 appears to be (finally) coming of age with the
influx of autonomous devices. In support of this, add
the ability to associate a Smack label with IPv6 addresses.
This patch also cleans up some of the conditional
compilation associated with the introduction of
secmark processing. It's now more obvious which bit
of code goes with which feature.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
security/smack/smackfs.c:2251:1-4: WARNING: end returns can be
simpified and declaration on line 2250 can be dropped
Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Add support for setting smack mount labels(using smackfsdef, smackfsroot,
smackfshat, smackfsfloor, smackfstransmute) for filesystems with binary
mount data like NFS.
To achieve this, implement sb_parse_opts_str and sb_set_mnt_opts security
operations in smack LSM similar to SELinux.
Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.
Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.
There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.
This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.
This set of changes also addresses an issue with how open file
descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of
/proc/<pid>/fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.
There is also a short list of issues that have not been fixed yet that
I will mention briefly.
It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.
As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.
The mount points converted and their filesystems are:
/sys/hypervisor/s390/ s390_hypfs
/sys/kernel/config/ configfs
/sys/kernel/debug/ debugfs
/sys/firmware/efi/efivars/ efivarfs
/sys/fs/fuse/connections/ fusectl
/sys/fs/pstore/ pstore
/sys/kernel/tracing/ tracefs
/sys/fs/cgroup/ cgroup
/sys/kernel/security/ securityfs
/sys/fs/selinux/ selinuxfs
/sys/fs/smackfs/ smackfs
Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This code used to rely on the fact that kfree(NULL) was a no-op, but
then we changed smk_parse_smack() to return error pointers on failure
instead of NULL. Calling kfree() on an error pointer will oops.
I have re-arranged things a bit so that we only free things if they
have been allocated.
Fixes: e774ad683f ('smack: pass error code through pointers')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Smack onlycap allows limiting of CAP_MAC_ADMIN and CAP_MAC_OVERRIDE to
processes running with the configured label. But having single privileged
label is not enough in some real use cases. On a complex system like Tizen,
there maybe few programs that need to configure Smack policy in run-time
and running them all with a single label is not always practical.
This patch extends onlycap feature for multiple labels. They are configured
in the same smackfs "onlycap" interface, separated by spaces.
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Use proper RCU functions and read locking in smackfs seq_operations.
Smack gets away with not using proper RCU functions in smackfs, because
it never removes entries from these lists. But now one list will be
needed (with interface in smackfs) that will have both elements added and
removed to it.
This change will also help any future changes implementing removal of
unneeded entries from other Smack lists.
The patch also fixes handling of pos argument in smk_seq_start and
smk_seq_next. This fixes a bug in case when smackfs is read with a small
buffer:
Kernel panic - not syncing: Kernel mode fault at addr 0xfa0000011b
CPU: 0 PID: 1292 Comm: dd Not tainted 4.1.0-rc1-00012-g98179b8 #13
Stack:
00000003 0000000d 7ff39e48 7f69fd00
7ff39ce0 601ae4b0 7ff39d50 600e587b
00000010 6039f690 7f69fd40 00612003
Call Trace:
[<601ae4b0>] load2_seq_show+0x19/0x1d
[<600e587b>] seq_read+0x168/0x331
[<600c5943>] __vfs_read+0x21/0x101
[<601a595e>] ? security_file_permission+0xf8/0x105
[<600c5ec6>] ? rw_verify_area+0x86/0xe2
[<600c5fc3>] vfs_read+0xa1/0x14c
[<600c68e2>] SyS_read+0x57/0xa0
[<6001da60>] handle_syscall+0x60/0x80
[<6003087d>] userspace+0x442/0x548
[<6001aa77>] ? interrupt_end+0x0/0x80
[<6001daae>] ? copy_chunk_to_user+0x0/0x2b
[<6002cb6b>] ? save_registers+0x1f/0x39
[<60032ef7>] ? arch_prctl+0xf5/0x170
[<6001a92d>] fork_handler+0x85/0x87
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
This patch makes the following functions to use ERR_PTR() and related
macros to pass the appropriate error code through returned pointers:
smk_parse_smack()
smk_import_entry()
smk_fetch()
It also makes all the other functions that use them to handle the
error cases properly. This ways correct error codes from places
where they happened can be propagated to the user space if necessary.
Doing this it fixes a bug in onlycap and unconfined files
handling. Previously their content was cleared on any error from
smk_import_entry/smk_parse_smack, be it EINVAL (as originally intended)
or ENOMEM. Right now it only reacts on EINVAL passing other codes
properly to userspace.
Comments have been updated accordingly.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
The dmabuf fd can be shared between processes via unix domain
socket. The file of dmabuf fd is came from anon_inode. The inode
has no set and get xattr operations, so it can not be shared
between processes with smack. This patch fixes just to ignore
private inode including anon_inode for smack_file_receive.
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
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>
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>
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
... except where that code acts as a filesystem driver, rather than
working with dentries given to it.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull security subsystem updates from James Morris:
"Highlights for this window:
- improved AVC hashing for SELinux by John Brooks and Stephen Smalley
- addition of an unconfined label to Smack
- Smack documentation update
- TPM driver updates"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (28 commits)
lsm: copy comm before calling audit_log to avoid race in string printing
tomoyo: Do not generate empty policy files
tomoyo: Use if_changed when generating builtin-policy.h
tomoyo: Use bin2c to generate builtin-policy.h
selinux: increase avtab max buckets
selinux: Use a better hash function for avtab
selinux: convert avtab hash table to flex_array
selinux: reconcile security_netlbl_secattr_to_sid() and mls_import_netlbl_cat()
selinux: remove unnecessary pointer reassignment
Smack: Updates for Smack documentation
tpm/st33zp24/spi: Add missing device table for spi phy.
tpm/st33zp24: Add proper wait for ordinal duration in case of irq mode
smack: Fix gcc warning from unused smack_syslog_lock mutex in smackfs.c
Smack: Allow an unconfined label in bringup mode
Smack: getting the Smack security context of keys
Smack: Assign smack_known_web as default smk_in label for kernel thread's socket
tpm/tpm_infineon: Use struct dev_pm_ops for power management
MAINTAINERS: Add Jason as designated reviewer for TPM
tpm: Update KConfig text to include TPM2.0 FIFO chips
tpm/st33zp24/dts/st33zp24-spi: Add dts documentation for st33zp24 spi phy
...
Pull networking updates from David Miller:
1) Add BQL support to via-rhine, from Tino Reichardt.
2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers
can support hw switch offloading. From Floria Fainelli.
3) Allow 'ip address' commands to initiate multicast group join/leave,
from Madhu Challa.
4) Many ipv4 FIB lookup optimizations from Alexander Duyck.
5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel
Borkmann.
6) Remove the ugly compat support in ARP for ugly layers like ax25,
rose, etc. And use this to clean up the neigh layer, then use it to
implement MPLS support. All from Eric Biederman.
7) Support L3 forwarding offloading in switches, from Scott Feldman.
8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed
up route lookups even further. From Alexander Duyck.
9) Many improvements and bug fixes to the rhashtable implementation,
from Herbert Xu and Thomas Graf. In particular, in the case where
an rhashtable user bulk adds a large number of items into an empty
table, we expand the table much more sanely.
10) Don't make the tcp_metrics hash table per-namespace, from Eric
Biederman.
11) Extend EBPF to access SKB fields, from Alexei Starovoitov.
12) Split out new connection request sockets so that they can be
established in the main hash table. Much less false sharing since
hash lookups go direct to the request sockets instead of having to
go first to the listener then to the request socks hashed
underneath. From Eric Dumazet.
13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk.
14) Support stable privacy address generation for RFC7217 in IPV6. From
Hannes Frederic Sowa.
15) Hash network namespace into IP frag IDs, also from Hannes Frederic
Sowa.
16) Convert PTP get/set methods to use 64-bit time, from Richard
Cochran.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits)
fm10k: Bump driver version to 0.15.2
fm10k: corrected VF multicast update
fm10k: mbx_update_max_size does not drop all oversized messages
fm10k: reset head instead of calling update_max_size
fm10k: renamed mbx_tx_dropped to mbx_tx_oversized
fm10k: update xcast mode before synchronizing multicast addresses
fm10k: start service timer on probe
fm10k: fix function header comment
fm10k: comment next_vf_mbx flow
fm10k: don't handle mailbox events in iov_event path and always process mailbox
fm10k: use separate workqueue for fm10k driver
fm10k: Set PF queues to unlimited bandwidth during virtualization
fm10k: expose tx_timeout_count as an ethtool stat
fm10k: only increment tx_timeout_count in Tx hang path
fm10k: remove extraneous "Reset interface" message
fm10k: separate PF only stats so that VF does not display them
fm10k: use hw->mac.max_queues for stats
fm10k: only show actual queues, not the maximum in hardware
fm10k: allow creation of VLAN on default vid
fm10k: fix unused warnings
...
In commit 00f84f3f2e ("Smack: Make the
syslog control configurable") this mutex was added, but the rest of
the final commit never actually made use of it, resulting in:
In file included from include/linux/mutex.h:29:0,
from include/linux/notifier.h:13,
from include/linux/memory_hotplug.h:6,
from include/linux/mmzone.h:821,
from include/linux/gfp.h:5,
from include/linux/slab.h:14,
from include/linux/security.h:27,
from security/smack/smackfs.c:21:
security/smack/smackfs.c:63:21: warning: ‘smack_syslog_lock’ defined but not used [-Wunused-variable]
static DEFINE_MUTEX(smack_syslog_lock);
^
A git grep shows no other instances/references to smack_syslog_lock.
Delete it, assuming that the mutex addition was just a leftover from
an earlier work in progress version of the change.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
I have vehemently opposed adding a "permissive" mode to Smack
for the simple reasons that it would be subject to massive abuse
and that developers refuse to turn it off come product release.
I still believe that this is true, and still refuse to add a
general "permissive mode". So don't ask again.
Bumjin Im suggested an approach that addresses most of the concerns,
and I have implemented it here. I still believe that we'd be better
off without this sort of thing, but it looks like this minimizes the
abuse potential.
Firstly, you have to configure Smack Bringup Mode. That allows
for "release" software to be ammune from abuse. Second, only one
label gets to be "permissive" at a time. You can use it for
debugging, but that's about it.
A label written to smackfs/unconfined is treated specially.
If either the subject or object label of an access check
matches the "unconfined" label, and the access would not
have been allowed otherwise an audit record and a console
message are generated. The audit record "request" string is
marked with either "(US)" or "(UO)", to indicate that the
request was granted because of an unconfined label. The
fact that an inode was accessed by an unconfined label is
remembered, and subsequent accesses to that "impure"
object are noted in the log. The impurity is not stored in
the filesystem, so a file mislabled as a side effect of
using an unconfined label may still cause concern after
a reboot.
So, it's there, it's dangerous, but so many application
developers seem incapable of living without it I have
given in. I've tried to make it as safe as I can, but
in the end it's still a chain saw.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
With this commit, the LSM Smack implements the LSM
side part of the system call keyctl with the action
code KEYCTL_GET_SECURITY.
It is now possible to get the context of, for example,
the user session key using the command "keyctl security @s".
The original patch has been modified for merge.
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This change fixes the bug associated with sockets owned by kernel threads. These
sockets, created usually by network devices' drivers tasks, received smk_in
label from the task that created them - the "floor" label in the most cases. The
result was that they were not able to receive data packets because of missing
smack rules. The main reason of the access deny is that the socket smk_in label
is placed as the object during smk check, kernel thread's capabilities are
omitted.
Signed-off-by: Marcin Lis <m.lis@samsung.com>
Use d_is_positive() rather than testing dentry->d_inode in Smack to get rid of
direct references to d_inode outside of the VFS.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
On 1/23/2015 8:20 AM, Jim Davis wrote:
> Building with the attached random configuration file,
>
> security/smack/smack_netfilter.c: In function ‘smack_ipv4_output’:
> security/smack/smack_netfilter.c:55:6: error: ‘struct sk_buff’ has no
> member named ‘secmark’
> skb->secmark = skp->smk_secid;
> ^
> make[2]: *** [security/smack/smack_netfilter.o] Error 1
The existing Makefile used the wrong configuration option to
determine if smack_netfilter should be built. This sets it right.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
We hit use after free on dereferncing pointer to task_smack struct in
smk_of_task() called from smack_task_to_inode().
task_security() macro uses task_cred_xxx() to get pointer to the task_smack.
task_cred_xxx() could be used only for non-pointer members of task's
credentials. It cannot be used for pointer members since what they point
to may disapper after dropping RCU read lock.
Mainly task_security() used this way:
smk_of_task(task_security(p))
Intead of this introduce function smk_of_task_struct() which
takes task_struct as argument and returns pointer to smk_known struct
and do this under RCU read lock.
Bogus task_security() macro is not used anymore, so remove it.
KASan's report for this:
AddressSanitizer: use after free in smack_task_to_inode+0x50/0x70 at addr c4635600
=============================================================================
BUG kmalloc-64 (Tainted: PO): kasan error
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: Allocated in new_task_smack+0x44/0xd8 age=39 cpu=0 pid=1866
kmem_cache_alloc_trace+0x88/0x1bc
new_task_smack+0x44/0xd8
smack_cred_prepare+0x48/0x21c
security_prepare_creds+0x44/0x4c
prepare_creds+0xdc/0x110
smack_setprocattr+0x104/0x150
security_setprocattr+0x4c/0x54
proc_pid_attr_write+0x12c/0x194
vfs_write+0x1b0/0x370
SyS_write+0x5c/0x94
ret_fast_syscall+0x0/0x48
INFO: Freed in smack_cred_free+0xc4/0xd0 age=27 cpu=0 pid=1564
kfree+0x270/0x290
smack_cred_free+0xc4/0xd0
security_cred_free+0x34/0x3c
put_cred_rcu+0x58/0xcc
rcu_process_callbacks+0x738/0x998
__do_softirq+0x264/0x4cc
do_softirq+0x94/0xf4
irq_exit+0xbc/0x120
handle_IRQ+0x104/0x134
gic_handle_irq+0x70/0xac
__irq_svc+0x44/0x78
_raw_spin_unlock+0x18/0x48
sync_inodes_sb+0x17c/0x1d8
sync_filesystem+0xac/0xfc
vdfs_file_fsync+0x90/0xc0
vfs_fsync_range+0x74/0x7c
INFO: Slab 0xd3b23f50 objects=32 used=31 fp=0xc4635600 flags=0x4080
INFO: Object 0xc4635600 @offset=5632 fp=0x (null)
Bytes b4 c46355f0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Object c4635600: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635610: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635620: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635630: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
Redzone c4635640: bb bb bb bb ....
Padding c46356e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding c46356f8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
CPU: 5 PID: 834 Comm: launchpad_prelo Tainted: PBO 3.10.30 #1
Backtrace:
[<c00233a4>] (dump_backtrace+0x0/0x158) from [<c0023dec>] (show_stack+0x20/0x24)
r7:c4634010 r6:d3b23f50 r5:c4635600 r4:d1002140
[<c0023dcc>] (show_stack+0x0/0x24) from [<c06d6d7c>] (dump_stack+0x20/0x28)
[<c06d6d5c>] (dump_stack+0x0/0x28) from [<c01c1d50>] (print_trailer+0x124/0x144)
[<c01c1c2c>] (print_trailer+0x0/0x144) from [<c01c1e88>] (object_err+0x3c/0x44)
r7:c4635600 r6:d1002140 r5:d3b23f50 r4:c4635600
[<c01c1e4c>] (object_err+0x0/0x44) from [<c01cac18>] (kasan_report_error+0x2b8/0x538)
r6:d1002140 r5:d3b23f50 r4:c6429cf8 r3:c09e1aa7
[<c01ca960>] (kasan_report_error+0x0/0x538) from [<c01c9430>] (__asan_load4+0xd4/0xf8)
[<c01c935c>] (__asan_load4+0x0/0xf8) from [<c031e168>] (smack_task_to_inode+0x50/0x70)
r5:c4635600 r4:ca9da000
[<c031e118>] (smack_task_to_inode+0x0/0x70) from [<c031af64>] (security_task_to_inode+0x3c/0x44)
r5:cca25e80 r4:c0ba9780
[<c031af28>] (security_task_to_inode+0x0/0x44) from [<c023d614>] (pid_revalidate+0x124/0x178)
r6:00000000 r5:cca25e80 r4:cbabe3c0 r3:00008124
[<c023d4f0>] (pid_revalidate+0x0/0x178) from [<c01db98c>] (lookup_fast+0x35c/0x43y4)
r9:c6429efc r8:00000101 r7:c079d940 r6:c6429e90 r5:c6429ed8 r4:c83c4148
[<c01db630>] (lookup_fast+0x0/0x434) from [<c01deec8>] (do_last.isra.24+0x1c0/0x1108)
[<c01ded08>] (do_last.isra.24+0x0/0x1108) from [<c01dff04>] (path_openat.isra.25+0xf4/0x648)
[<c01dfe10>] (path_openat.isra.25+0x0/0x648) from [<c01e1458>] (do_filp_open+0x3c/0x88)
[<c01e141c>] (do_filp_open+0x0/0x88) from [<c01ccb28>] (do_sys_open+0xf0/0x198)
r7:00000001 r6:c0ea2180 r5:0000000b r4:00000000
[<c01cca38>] (do_sys_open+0x0/0x198) from [<c01ccc00>] (SyS_open+0x30/0x34)
[<c01ccbd0>] (SyS_open+0x0/0x34) from [<c001db80>] (ret_fast_syscall+0x0/0x48)
Read of size 4 by thread T834:
Memory state around the buggy address:
c4635380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635400: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
c4635480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635500: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
c4635580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>c4635600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
c4635680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
c4635700: 00 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc
c4635780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635800: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc
c4635880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: <stable@vger.kernel.org>
During UDS connection check, both sides are checked for write access to
the other side. But only the first check is performed with audit support.
The second one didn't produce any audit logs. This simple patch fixes that.
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Smack uses CIPSO to label internet packets and thus provide
for access control on delivery of packets. The netfilter facility
was not used to allow for Smack to work properly without netfilter
configuration. Smack does not need netfilter, however there are
cases where it would be handy.
As a side effect, the labeling of local IPv4 packets can be optimized
and the handling of local IPv6 packets is just all out better.
The best part is that the netfilter tools use "contexts" that
are just strings, and they work just as well for Smack as they
do for SELinux.
All of the conditional compilation for IPv6 was implemented
by Rafal Krypa <r.krypa@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This is one of those cases where you look at code you did
years ago and wonder what you might have been thinking.
There are a number of LSM hooks that work off of file pointers,
and most of them really want the security data from the inode.
Some, however, really want the security context that the process
had when the file was opened. The difference went undetected in
Smack until it started getting used in a real system with real
testing. At that point it was clear that something was amiss.
This patch corrects the misuse of the f_security value in several
of the hooks. The behavior will not usually be any different, as
the process had to be able to open the file in the first place, and
the old check almost always succeeded, as will the new, but for
different reasons.
Thanks to the Samsung Tizen development team that identified this.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
The 54e70ec5eb commit introduced a
bidirectional check that should have checked for mutual WRITE access
between two labels. Due to a typo subject's OUT label is checked with
object's OUT. Should be OUT to IN.
Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Files created with __shmem_file_stup() appear to have somewhat fake
dentries which make them look like root directories and not get
the label the current process or ("*") star meant for tmpfs files.
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
In principle if this function was called with "value" == NULL and "len"
not NULL it could return different results for the "len" compared to a
case where "name" was not NULL. This is a hypothetical case that does
not exist in the kernel, but it's a logic bug nonetheless.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Pull security layer updates from James Morris:
"In terms of changes, there's general maintenance to the Smack,
SELinux, and integrity code.
The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
which allows IMA appraisal to require signatures. Support for reading
keys from rootfs before init is call is also added"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
selinux: Remove security_ops extern
security: smack: fix out-of-bounds access in smk_parse_smack()
VFS: refactor vfs_read()
ima: require signature based appraisal
integrity: provide a hook to load keys when rootfs is ready
ima: load x509 certificate from the kernel
integrity: provide a function to load x509 certificate from the kernel
integrity: define a new function integrity_read_file()
Security: smack: replace kzalloc with kmem_cache for inode_smack
Smack: Lock mode for the floor and hat labels
ima: added support for new kernel cmdline parameter ima_template_fmt
ima: allocate field pointers array on demand in template_desc_init_fields()
ima: don't allocate a copy of template_fmt in template_desc_init_fields()
ima: display template format in meas. list if template name length is zero
ima: added error messages to template-related functions
ima: use atomic bit operations to protect policy update interface
ima: ignore empty and with whitespaces policy lines
ima: no need to allocate entry for comment
ima: report policy load status
ima: use path names cache
...
The patch use kmem_cache to allocate/free inode_smack since they are
alloced in high volumes making it a perfect case for kmem_cache.
As per analysis, 24 bytes of memory is wasted per allocation due
to internal fragmentation. With kmem_cache, this can be avoided.
Accounting of memory allocation is below :
total slack net count-alloc/free caller
Before (with kzalloc)
1919872 719952 1919872 29998/0 new_inode_smack+0x14
After (with kmem_cache)
1201680 0 1201680 30042/0 new_inode_smack+0x18
>From above data, we found that 719952 bytes(~700 KB) of memory is
saved on allocation of 29998 smack inodes.
Signed-off-by: Rohit <rohit.kr@samsung.com>
The lock access mode allows setting a read lock on a file
for with the process has only read access. The floor label is
defined to make it easy to have the basic system installed such
that everyone can read it. Once there's a desire to read lock
(rationally or otherwise) a floor file a rule needs to get set.
This happens all the time, so make the floor label a little bit
more special and allow everyone lock access, too. By implication,
give processes with the hat label (hat can read everything)
lock access as well. This reduces clutter in the Smack rule set.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Pull security subsystem updates from James Morris.
Mostly ima, selinux, smack and key handling updates.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
integrity: do zero padding of the key id
KEYS: output last portion of fingerprint in /proc/keys
KEYS: strip 'id:' from ca_keyid
KEYS: use swapped SKID for performing partial matching
KEYS: Restore partial ID matching functionality for asymmetric keys
X.509: If available, use the raw subjKeyId to form the key description
KEYS: handle error code encoded in pointer
selinux: normalize audit log formatting
selinux: cleanup error reporting in selinux_nlmsg_perm()
KEYS: Check hex2bin()'s return when generating an asymmetric key ID
ima: detect violations for mmaped files
ima: fix race condition on ima_rdwr_violation_check and process_measurement
ima: added ima_policy_flag variable
ima: return an error code from ima_add_boot_aggregate()
ima: provide 'ima_appraise=log' kernel option
ima: move keyring initialization to ima_init()
PKCS#7: Handle PKCS#7 messages that contain no X.509 certs
PKCS#7: Better handling of unsupported crypto
KEYS: Overhaul key identification when searching for asymmetric keys
KEYS: Implement binary asymmetric key ID handling
...
security_file_set_fowner always returns 0, so make it f_setown and
__f_setown void return functions and fix up the error handling in the
callers.
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Smack used to use a mix of smack_known struct and char* throughout its
APIs and implementation. This patch unifies the behaviour and makes it
store and operate exclusively on smack_known struct pointers when managing
labels.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Conflicts:
security/smack/smack_access.c
security/smack/smack_lsm.c
The 54e70ec5eb commit introduced a
bidirectional check that should have checked for mutual WRITE access
between two labels. Due to a typo the second check was incorrect.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
People keep asking me for permissive mode, and I keep saying "no".
Permissive mode is wrong for more reasons than I can enumerate,
but the compelling one is that it's once on, never off.
Nonetheless, there is an argument to be made for running a
process with lots of permissions, logging which are required,
and then locking the process down. There wasn't a way to do
that with Smack, but this provides it.
The notion is that you start out by giving the process an
appropriate Smack label, such as "ATBirds". You create rules
with a wide range of access and the "b" mode. On Tizen it
might be:
ATBirds System rwxalb
ATBirds User rwxalb
ATBirds _ rwxalb
User ATBirds wb
System ATBirds wb
Accesses that fail will generate audit records. Accesses
that succeed because of rules marked with a "b" generate
log messages identifying the rule, the program and as much
object information as is convenient.
When the system is properly configured and the programs
brought in line with the labeling scheme the "b" mode can
be removed from the rules. When the system is ready for
production the facility can be configured out.
This provides the developer the convenience of permissive
mode without creating a system that looks like it is
enforcing a policy while it is not.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
While opening with CAP_MAC_OVERRIDE file label is not set.
Other calls may access it after CAP_MAC_OVERRIDE is dropped from process.
Signed-off-by: Marcin Niesluchowski <m.niesluchow@samsung.com>
Values of extended attributes are stored as binary blobs. NULL-termination
of them isn't required. It just wastes disk space and confuses command-line
tools like getfattr because they have to print that zero byte at the end.
This patch removes terminating zero byte from initial security label in
smack_inode_init_security and cuts it out in function smack_inode_getsecurity
which is used by syscall getxattr. This change seems completely safe, because
function smk_parse_smack ignores everything after first zero byte.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Zero-length security labels are invalid but kernel should handle them.
This patch fixes kernel panic after setting zero-length security labels:
# attr -S -s "SMACK64" -V "" file
And after writing zero-length string into smackfs files syslog and onlycp:
# python -c 'import os; os.write(1, "")' > /smack/syslog
The problem is caused by brain-damaged logic in function smk_parse_smack()
which takes pointer to buffer and its length but if length below or equal zero
it thinks that the buffer is zero-terminated. Unfortunately callers of this
function are widely used and proper fix requires serious refactoring.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Security operation ->inode_listsecurity is used for generating list of
available extended attributes for syscall listxattr. Currently it's used
only in nfs4 or if filesystem doesn't provide i_op->listxattr.
The list is the set of NULL-terminated names, one after the other.
This method must include zero byte at the and into result.
Also this function must return length even if string does not fit into
output buffer or it is NULL, see similar method in selinux and man listxattr.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Historically the NetLabel LSM secattr catmap functions and data
structures have had very long names which makes a mess of the NetLabel
code and anyone who uses NetLabel. This patch renames the catmap
functions and structures from "*_secattr_catmap_*" to just "*_catmap_*"
which improves things greatly.
There are no substantial code or logic changes in this patch.
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
The NetLabel secattr catmap functions, and the SELinux import/export
glue routines, were broken in many horrible ways and the SELinux glue
code fiddled with the NetLabel catmap structures in ways that we
probably shouldn't allow. At some point this "worked", but that was
likely due to a bit of dumb luck and sub-par testing (both inflicted
by yours truly). This patch corrects these problems by basically
gutting the code in favor of something less obtuse and restoring the
NetLabel abstractions in the SELinux catmap glue code.
Everything is working now, and if it decides to break itself in the
future this code will be much easier to debug than the code it
replaces.
One noteworthy side effect of the changes is that it is no longer
necessary to allocate a NetLabel catmap before calling one of the
NetLabel APIs to set a bit in the catmap. NetLabel will automatically
allocate the catmap nodes when needed, resulting in less allocations
when the lowest bit is greater than 255 and less code in the LSMs.
Cc: stable@vger.kernel.org
Reported-by: Christian Evans <frodox@zoho.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
The NetLabel category (catmap) functions have a problem in that they
assume categories will be set in an increasing manner, e.g. the next
category set will always be larger than the last. Unfortunately, this
is not a valid assumption and could result in problems when attempting
to set categories less than the startbit in the lowest catmap node.
In some cases kernel panics and other nasties can result.
This patch corrects the problem by checking for this and allocating a
new catmap node instance and placing it at the front of the list.
Cc: stable@vger.kernel.org
Reported-by: Christian Evans <frodox@zoho.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
The cgroup filesystem isn't ready for an LSM to
properly use extented attributes. This patch makes
files created in the cgroup filesystem usable by
a system running Smack and systemd.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Smack believes that many of the operatons that can
be performed on an open file descriptor are read operations.
The fstat and lseek system calls are examples.
An implication of this is that files shouldn't be open
if the task doesn't have read access even if it has
write access and the file is being opened write only.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Smack IPC policy requires that the sender have write access
to the receiver. UDS streams don't do per-packet checks. The
only check is done at connect time. The existing code checks
if the connecting process can write to the other, but not the
other way around. This change adds a check that the other end
can write to the connecting process.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schuafler <casey@schaufler-ca.com>
Sam Henderson points out that removing the SMACK64TRANSMUTE
attribute from a directory does not result in the directory
transmuting. This is because the inode flag indicating that
the directory is transmuting isn't cleared. The fix is a tad
less than trivial because smk_task and smk_mmap should have
been broken out, too.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
The function `smack_inode_post_setxattr` is called each
time that a setxattr is done, for any value of name.
The kernel allow to put value==NULL when size==0
to set an empty attribute value. The systematic
call to smk_import_entry was causing the dereference
of a NULL pointer hence a KERNEL PANIC!
The problem can be produced easily by issuing the
command `setfattr -n user.data file` under bash prompt
when SMACK is active.
Moving the call to smk_import_entry as proposed by this
patch is correcting the behaviour because the function
smack_inode_post_setxattr is called for the SMACK's
attributes only if the function smack_inode_setxattr validated
the value and its size (what will not be the case when size==0).
It also has a benefical effect to not fill the smack hash
with garbage values coming from any extended attribute
write.
Change-Id: Iaf0039c2be9bccb6cee11c24a3b44d209101fe47
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
1. In order to remove any SMACK extended attribute from a file, a user
should have CAP_MAC_ADMIN capability. But user without having this
capability is able to remove SMACK64MMAP security attribute.
2. While validating size and value of smack extended attribute in
smack_inode_setsecurity hook, wrong error code is returned.
Signed-off-by: Pankaj Kumar <pamkaj.k2@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
This allows to limit ptrace beyond the regular smack access rules.
It adds a smackfs/ptrace interface that allows smack to be configured
to require equal smack labels for PTRACE_MODE_ATTACH access.
See the changes in Documentation/security/Smack.txt below for details.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
The decision whether we can trace a process is made in the following
functions:
smack_ptrace_traceme()
smack_ptrace_access_check()
smack_bprm_set_creds() (in case the proces is traced)
This patch unifies all those decisions by introducing one function that
checks whether ptrace is allowed: smk_ptrace_rule_check().
This makes possible to actually trace with TRACEME where first the
TRACEME itself must be allowed and then exec() on a traced process.
Additional bugs fixed:
- The decision is made according to the mode parameter that is now correctly
translated from PTRACE_MODE_* to MAY_* instead of being treated 1:1.
PTRACE_MODE_READ requires MAY_READ.
PTRACE_MODE_ATTACH requires MAY_READWRITE.
- Add a smack audit log in case of exec() refused by bprm_set_creds().
- Honor the PTRACE_MODE_NOAUDIT flag and don't put smack audit info
in case this flag is set.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
