4920 Commits

Author SHA1 Message Date
Tianjia Zhang
0b7e44d39c integrity: Asymmetric digsig supports SM2-with-SM3 algorithm
Asymmetric digsig supports SM2-with-SM3 algorithm combination,
so that IMA can also verify SM2's signature data.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Tested-by: Xufeng Zhang <yunbo.xufeng@linux.alibaba.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-25 17:48:55 +10:00
David S. Miller
3ab0a7a0c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22 16:45:34 -07:00
Casey Schaufler
bf0afe673b Smack: Fix build when NETWORK_SECMARK is not set
Use proper conditional compilation for the secmark field in
the network skb.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-09-22 14:59:31 -07:00
KP Singh
aa662fc04f ima: Fix NULL pointer dereference in ima_file_hash
ima_file_hash can be called when there is no iint->ima_hash available
even though the inode exists in the integrity cache. It is fairly
common for a file to not have a hash. (e.g. an mknodat, prior to the
file being closed).

Another example where this can happen (suggested by Jann Horn):

Process A does:

	while(1) {
		unlink("/tmp/imafoo");
		fd = open("/tmp/imafoo", O_RDWR|O_CREAT|O_TRUNC, 0700);
		if (fd == -1) {
			perror("open");
			continue;
		}
		write(fd, "A", 1);
		close(fd);
	}

and Process B does:

	while (1) {
		int fd = open("/tmp/imafoo", O_RDONLY);
		if (fd == -1)
			continue;
    		char *mapping = mmap(NULL, 0x1000, PROT_READ|PROT_EXEC,
			 	     MAP_PRIVATE, fd, 0);
		if (mapping != MAP_FAILED)
			munmap(mapping, 0x1000);
		close(fd);
  	}

Due to the race to get the iint->mutex between ima_file_hash and
process_measurement iint->ima_hash could still be NULL.

Fixes: 6beea7afcc72 ("ima: add the ability to query the cached hash of a given file")
Signed-off-by: KP Singh <kpsingh@google.com>
Reviewed-by: Florent Revest <revest@chromium.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-16 17:43:02 -04:00
Lenny Szubowicz
726bd8965a integrity: Load certs from the EFI MOK config table
Because of system-specific EFI firmware limitations, EFI volatile
variables may not be capable of holding the required contents of
the Machine Owner Key (MOK) certificate store when the certificate
list grows above some size. Therefore, an EFI boot loader may pass
the MOK certs via a EFI configuration table created specifically for
this purpose to avoid this firmware limitation.

An EFI configuration table is a much more primitive mechanism
compared to EFI variables and is well suited for one-way passage
of static information from a pre-OS environment to the kernel.

This patch adds the support to load certs from the MokListRT
entry in the MOK variable configuration table, if it's present.
The pre-existing support to load certs from the MokListRT EFI
variable remains and is used if the EFI MOK configuration table
isn't present or can't be successfully used.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Link: https://lore.kernel.org/r/20200905013107.10457-4-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16 18:53:42 +03:00
Lenny Szubowicz
38a1f03aa2 integrity: Move import of MokListRT certs to a separate routine
Move the loading of certs from the UEFI MokListRT into a separate
routine to facilitate additional MokList functionality.

There is no visible functional change as a result of this patch.
Although the UEFI dbx certs are now loaded before the MokList certs,
they are loaded onto different key rings. So the order of the keys
on their respective key rings is the same.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20200905013107.10457-3-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16 18:53:42 +03:00
Linus Torvalds
1e484d3887 device_cgroup RCU warning fix from Amol Grover <frextrite@gmail.com>
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Merge tag 'fixes-v5.9a' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security layer fix from James  Morris:
 "A device_cgroup RCU warning fix from Amol Grover"

* tag 'fixes-v5.9a' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  device_cgroup: Fix RCU list debugging warning
2020-09-15 16:26:57 -07:00
Lakshmi Ramasubramanian
8861d0af64 selinux: Add helper functions to get and set checkreqprot
checkreqprot data member in selinux_state struct is accessed directly by
SELinux functions to get and set. This could cause unexpected read or
write access to this data member due to compiler optimizations and/or
compiler's reordering of access to this field.

Add helper functions to get and set checkreqprot data member in
selinux_state struct. These helper functions use READ_ONCE and
WRITE_ONCE macros to ensure atomic read or write of memory for
this data member.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Suggested-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-09-15 14:36:28 -04:00
Roberto Sassu
455b6c9112 evm: Check size of security.evm before using it
This patch checks the size for the EVM_IMA_XATTR_DIGSIG and
EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from
the buffer returned by vfs_getxattr_alloc().

Cc: stable@vger.kernel.org # 4.19.x
Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-15 13:47:42 -04:00
Roberto Sassu
4be92db3b5 ima: Remove semicolon at the end of ima_get_binary_runtime_size()
This patch removes the unnecessary semicolon at the end of
ima_get_binary_runtime_size().

Cc: stable@vger.kernel.org
Fixes: d158847ae89a2 ("ima: maintain memory size needed for serializing the measurement list")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-15 13:47:41 -04:00
Roberto Sassu
60386b8540 ima: Don't ignore errors from crypto_shash_update()
Errors returned by crypto_shash_update() are not checked in
ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next
iteration of the loop. This patch adds a check after calling
crypto_shash_update() and returns immediately if the result is not zero.

Cc: stable@vger.kernel.org
Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-15 13:47:37 -04:00
Alex Dewar
f60c826d03 ima: Use kmemdup rather than kmalloc+memcpy
Issue identified with Coccinelle.

Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-15 09:57:48 -04:00
Casey Schaufler
322dd63c7f Smack: Use the netlabel cache
Utilize the Netlabel cache mechanism for incoming packet matching.
Refactor the initialization of secattr structures, as it was being
done in two places.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-09-11 15:31:31 -07:00
Casey Schaufler
a2af031885 Smack: Set socket labels only once
Refactor the IP send checks so that the netlabel value
is set only when necessary, not on every send. Some functions
get renamed as the changes made the old name misleading.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-09-11 15:31:30 -07:00
Casey Schaufler
36be81293d Smack: Consolidate uses of secmark into a function
Add a function smack_from_skb() that returns the Smack label
identified by a network secmark. Replace the explicit uses of
the secmark with this function.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-09-11 15:31:30 -07:00
Stephen Smalley
e8ba53d002 selinux: access policycaps with READ_ONCE/WRITE_ONCE
Use READ_ONCE/WRITE_ONCE for all accesses to the
selinux_state.policycaps booleans to prevent compiler
mischief.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-09-11 10:08:51 -04:00
Bruno Meneguele
8c2f516c99 integrity: include keyring name for unknown key request
Depending on the IMA policy rule a key may be searched for in multiple
keyrings (e.g. .ima and .platform) and possibly not found.  This patch
improves feedback by including the keyring "description" (name) in the
error message.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
[zohar@linux.ibm.com: updated commit message]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-09 20:05:28 -04:00
Bruno Meneguele
e4d7e2df3a ima: limit secure boot feedback scope for appraise
Only emit an unknown/invalid message when setting the IMA appraise mode
to anything other than "enforce", when secureboot is enabled.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
[zohar@linux.ibm.com: updated commit message]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-09 20:01:55 -04:00
Bruno Meneguele
7fe2bb7e7e integrity: invalid kernel parameters feedback
Don't silently ignore unknown or invalid ima_{policy,appraise,hash} and evm
kernel boot command line options.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-08 22:03:50 -04:00
Bruno Meneguele
4afb28ab03 ima: add check for enforced appraise option
The "enforce" string is allowed as an option for ima_appraise= kernel
paramenter per kernel-paramenters.txt and should be considered on the
parameter setup checking as a matter of completeness. Also it allows futher
checking on the options being passed by the user.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-09-08 22:02:57 -04:00
Jakub Kicinski
44a8c4f33c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.

Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444a4 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-04 21:28:59 -07:00
Denis Efremov
e44f128768 integrity: Use current_uid() in integrity_audit_message()
Modify integrity_audit_message() to use current_uid().

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-08-31 17:46:50 -04:00
Tyler Hicks
48ce1ddce1 ima: Fail rule parsing when asymmetric key measurement isn't supportable
Measuring keys is currently only supported for asymmetric keys. In the
future, this might change.

For now, the "func=KEY_CHECK" and "keyrings=" options are only
appropriate when CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Make
this clear at policy load so that IMA policy authors don't assume that
these policy language constructs are supported.

Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy")
Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys")
Suggested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-08-31 17:45:14 -04:00
Tyler Hicks
176377d97d ima: Pre-parse the list of keyrings in a KEY_CHECK rule
The ima_keyrings buffer was used as a work buffer for strsep()-based
parsing of the "keyrings=" option of an IMA policy rule. This parsing
was re-performed each time an asymmetric key was added to a kernel
keyring for each loaded policy rule that contained a "keyrings=" option.

An example rule specifying this option is:

 measure func=KEY_CHECK keyrings=a|b|c

The rule says to measure asymmetric keys added to any of the kernel
keyrings named "a", "b", or "c". The size of the buffer size was
equal to the size of the largest "keyrings=" value seen in a previously
loaded rule (5 + 1 for the NUL-terminator in the previous example) and
the buffer was pre-allocated at the time of policy load.

The pre-allocated buffer approach suffered from a couple bugs:

1) There was no locking around the use of the buffer so concurrent key
   add operations, to two different keyrings, would result in the
   strsep() loop of ima_match_keyring() to modify the buffer at the same
   time. This resulted in unexpected results from ima_match_keyring()
   and, therefore, could cause unintended keys to be measured or keys to
   not be measured when IMA policy intended for them to be measured.

2) If the kstrdup() that initialized entry->keyrings in ima_parse_rule()
   failed, the ima_keyrings buffer was freed and set to NULL even when a
   valid KEY_CHECK rule was previously loaded. The next KEY_CHECK event
   would trigger a call to strcpy() with a NULL destination pointer and
   crash the kernel.

Remove the need for a pre-allocated global buffer by parsing the list of
keyrings in a KEY_CHECK rule at the time of policy load. The
ima_rule_entry will contain an array of string pointers which point to
the name of each keyring specified in the rule. No string processing
needs to happen at the time of asymmetric key add so iterating through
the list and doing a string comparison is all that's required at the
time of policy check.

In the process of changing how the "keyrings=" policy option is handled,
a couple additional bugs were fixed:

1) The rule parser accepted rules containing invalid "keyrings=" values
   such as "a|b||c", "a|b|", or simply "|".

2) The /sys/kernel/security/ima/policy file did not display the entire
   "keyrings=" value if the list of keyrings was longer than what could
   fit in the fixed size tbuf buffer in ima_policy_show().

Fixes: 5c7bac9fb2c5 ("IMA: pre-allocate buffer to hold keyrings string")
Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-08-31 17:45:02 -04:00
Ondrej Mosnacek
66ccd2560a selinux: simplify away security_policydb_len()
Remove the security_policydb_len() calls from sel_open_policy() and
instead update the inode size from the size returned from
security_read_policy().

Since after this change security_policydb_len() is only called from
security_load_policy(), remove it entirely and just open-code it there.

Also, since security_load_policy() is always called with policy_mutex
held, make it dereference the policy pointer directly and drop the
unnecessary RCU locking.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-31 10:00:14 -04:00
Stephen Smalley
9ff9abc4c6 selinux: move policy mutex to selinux_state, use in lockdep checks
Move the mutex used to synchronize policy changes (reloads and setting
of booleans) from selinux_fs_info to selinux_state and use it in
lockdep checks for rcu_dereference_protected() calls in the security
server functions.  This makes the dependency on the mutex explicit
in the code rather than relying on comments.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-27 09:52:47 -04:00
Dan Carpenter
0256b0aa80 selinux: fix error handling bugs in security_load_policy()
There are a few bugs in the error handling for security_load_policy().

1) If the newpolicy->sidtab allocation fails then it leads to a NULL
   dereference.  Also the error code was not set to -ENOMEM on that
   path.
2) If policydb_read() failed then we call policydb_destroy() twice
   which meands we call kvfree(p->sym_val_to_name[i]) twice.
3) If policydb_load_isids() failed then we call sidtab_destroy() twice
   and that results in a double free in the sidtab_destroy_tree()
   function because entry.ptr_inner and entry.ptr_leaf are not set to
   NULL.

One thing that makes this code nice to deal with is that none of the
functions return partially allocated data.  In other words, the
policydb_read() either allocates everything successfully or it frees
all the data it allocates.  It never returns a mix of allocated and
not allocated data.

I re-wrote this to only free the successfully allocated data which
avoids the double frees.  I also re-ordered selinux_policy_free() so
it's in the reverse order of the allocation function.

Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[PM: partially merged by hand due to merge fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-26 10:19:08 -04:00
KP Singh
8ea636848a bpf: Implement bpf_local_storage for inodes
Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the storage is destroyed along with the owning inode.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the
security blob which are now stackable and can co-exist with other LSMs.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-6-kpsingh@chromium.org
2020-08-25 15:00:04 -07:00
Stephen Smalley
1b8b31a2e6 selinux: convert policy read-write lock to RCU
Convert the policy read-write lock to RCU.  This is significantly
simplified by the earlier work to encapsulate the policy data
structures and refactor the policy load and boolean setting logic.
Move the latest_granting sequence number into the selinux_policy
structure so that it can be updated atomically with the policy.
Since removing the policy rwlock and moving latest_granting reduces
the selinux_ss structure to nothing more than a wrapper around the
selinux_policy pointer, get rid of the extra layer of indirection.

At present this change merely passes a hardcoded 1 to
rcu_dereference_check() in the cases where we know we do not need to
take rcu_read_lock(), with the preceding comment explaining why.
Alternatively we could pass fsi->mutex down from selinuxfs and
apply a lockdep check on it instead.

Based in part on earlier attempts to convert the policy rwlock
to RCU by Kaigai Kohei [1] and by Peter Enderborg [2].

[1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/
[2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-25 08:34:47 -04:00
Randy Dunlap
c76a2f9ecd selinux: delete repeated words in comments
Drop a repeated word in comments.
{open, is, then}

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: selinux@vger.kernel.org
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
[PM: fix subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-24 09:03:14 -04:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Peter Enderborg
30969bc8e0 selinux: add basic filtering for audit trace events
This patch adds further attributes to the event. These attributes are
helpful to understand the context of the message and can be used
to filter the events.

There are three common items. Source context, target context and tclass.
There are also items from the outcome of operation performed.

An event is similar to:
           <...>-1309  [002] ....  6346.691689: selinux_audited:
       requested=0x4000000 denied=0x4000000 audited=0x4000000
       result=-13
       scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023
       tcontext=system_u:object_r:bin_t:s0 tclass=file

With systems where many denials are occurring, it is useful to apply a
filter. The filtering is a set of logic that is inserted with
the filter file. Example:
 echo "tclass==\"file\" " > events/avc/selinux_audited/filter

This adds that we only get tclass=file.

The trace can also have extra properties. Adding the user stack
can be done with
   echo 1 > options/userstacktrace

Now the output will be
         runcon-1365  [003] ....  6960.955530: selinux_audited:
     requested=0x4000000 denied=0x4000000 audited=0x4000000
     result=-13
     scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023
     tcontext=system_u:object_r:bin_t:s0 tclass=file
          runcon-1365  [003] ....  6960.955560: <user stack trace>
 =>  <00007f325b4ce45b>
 =>  <00005607093efa57>

Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Reviewed-by: Thiébaud Weksteen <tweek@google.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 17:07:29 -04:00
Thiébaud Weksteen
dd8166212d selinux: add tracepoint on audited events
The audit data currently captures which process and which target
is responsible for a denial. There is no data on where exactly in the
process that call occurred. Debugging can be made easier by being able to
reconstruct the unified kernel and userland stack traces [1]. Add a
tracepoint on the SELinux denials which can then be used by userland
(i.e. perf).

Although this patch could manually be added by each OS developer to
trouble shoot a denial, adding it to the kernel streamlines the
developers workflow.

It is possible to use perf for monitoring the event:
  # perf record -e avc:selinux_audited -g -a
  ^C
  # perf report -g
  [...]
      6.40%     6.40%  audited=800000 tclass=4
               |
                  __libc_start_main
                  |
                  |--4.60%--__GI___ioctl
                  |          entry_SYSCALL_64
                  |          do_syscall_64
                  |          __x64_sys_ioctl
                  |          ksys_ioctl
                  |          binder_ioctl
                  |          binder_set_nice
                  |          can_nice
                  |          capable
                  |          security_capable
                  |          cred_has_capability.isra.0
                  |          slow_avc_audit
                  |          common_lsm_audit
                  |          avc_audit_post_callback
                  |          avc_audit_post_callback
                  |

It is also possible to use the ftrace interface:
  # echo 1 > /sys/kernel/debug/tracing/events/avc/selinux_audited/enable
  # cat /sys/kernel/debug/tracing/trace
  tracer: nop
  entries-in-buffer/entries-written: 1/1   #P:8
  [...]
  dmesg-3624  [001] 13072.325358: selinux_denied: audited=800000 tclass=4

The tclass value can be mapped to a class by searching
security/selinux/flask.h. The audited value is a bit field of the
permissions described in security/selinux/av_permissions.h for the
corresponding class.

[1] https://source.android.com/devices/tech/debug/native_stack_dump

Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Suggested-by: Joel Fernandes <joelaf@google.com>
Reviewed-by: Peter Enderborg <peter.enderborg@sony.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 17:05:22 -04:00
Daniel Burgener
0eea609153 selinux: Create new booleans and class dirs out of tree
In order to avoid concurrency issues around selinuxfs resource availability
during policy load, we first create new directories out of tree for
reloaded resources, then swap them in, and finally delete the old versions.

This fix focuses on concurrency in each of the two subtrees swapped, and
not concurrency between the trees.  This means that it is still possible
that subsequent reads to eg the booleans directory and the class directory
during a policy load could see the old state for one and the new for the other.
The problem of ensuring that policy loads are fully atomic from the perspective
of userspace is larger than what is dealt with here.  This commit focuses on
ensuring that the directories contents always match either the new or the old
policy state from the perspective of userspace.

In the previous implementation, on policy load /sys/fs/selinux is updated
by deleting the previous contents of
/sys/fs/selinux/{class,booleans} and then recreating them.  This means
that there is a period of time when the contents of these directories do not
exist which can cause race conditions as userspace relies on them for
information about the policy.  In addition, it means that error recovery in
the event of failure is challenging.

In order to demonstrate the race condition that this series fixes, you
can use the following commands:

while true; do cat /sys/fs/selinux/class/service/perms/status
>/dev/null; done &
while true; do load_policy; done;

In the existing code, this will display errors fairly often as the class
lookup fails.  (In normal operation from systemd, this would result in a
permission check which would be allowed or denied based on policy settings
around unknown object classes.) After applying this patch series you
should expect to no longer see such error messages.

Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 09:41:31 -04:00
Daniel Burgener
613ba18798 selinux: Standardize string literal usage for selinuxfs directory names
Switch class and policy_capabilities directory names to be referred to with
global constants, consistent with booleans directory name.  This will allow
for easy consistency of naming in future development.

Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 09:39:10 -04:00
Daniel Burgener
66ec384ad3 selinux: Refactor selinuxfs directory populating functions
Make sel_make_bools and sel_make_classes take the specific elements of
selinux_fs_info that they need rather than the entire struct.

This will allow a future patch to pass temporary elements that are not in
the selinux_fs_info struct to these functions so that the original elements
can be preserved until we are ready to perform the switch over.

Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 09:37:12 -04:00
Daniel Burgener
aeecf4a3fb selinux: Create function for selinuxfs directory cleanup
Separating the cleanup from the creation will simplify two things in
future patches in this series.  First, the creation can be made generic,
to create directories not tied to the selinux_fs_info structure.  Second,
we will ultimately want to reorder creation and deletion so that the
deletions aren't performed until the new directory structures have already
been moved into place.

Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21 09:35:59 -04:00
Stephen Smalley
9530a3e004 selinux: permit removing security.selinux xattr before policy load
Currently SELinux denies attempts to remove the security.selinux xattr
always, even when permissive or no policy is loaded.  This was originally
motivated by the view that all files should be labeled, even if that label
is unlabeled_t, and we shouldn't permit files that were once labeled to
have their labels removed entirely.  This however prevents removing
SELinux xattrs in the case where one "disables" SELinux by not loading
a policy (e.g. a system where runtime disable is removed and selinux=0
was not specified).  Allow removing the xattr before SELinux is
initialized.  We could conceivably permit it even after initialization
if permissive, or introduce a separate permission check here.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-20 21:55:31 -04:00
Amol Grover
bc62d68e2a device_cgroup: Fix RCU list debugging warning
exceptions may be traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section BUT under the
protection of decgroup_mutex. Hence add the corresponding
lockdep expression to fix the following false-positive
warning:

[    2.304417] =============================
[    2.304418] WARNING: suspicious RCU usage
[    2.304420] 5.5.4-stable #17 Tainted: G            E
[    2.304422] -----------------------------
[    2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!!

Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
2020-08-20 11:25:03 -07:00
kernel test robot
879229311b selinux: fix memdup.cocci warnings
Use kmemdup rather than duplicating its implementation

Generated by: scripts/coccinelle/api/memdup.cocci

Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
CC: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-20 08:39:05 -04:00
Stephen Smalley
37ea433c66 selinux: avoid dereferencing the policy prior to initialization
Certain SELinux security server functions (e.g. security_port_sid,
called during bind) were not explicitly testing to see if SELinux
has been initialized (i.e. initial policy loaded) and handling
the no-policy-loaded case.  In the past this happened to work
because the policydb was statically allocated and could always
be accessed, but with the recent encapsulation of policy state
and conversion to dynamic allocation, we can no longer access
the policy state prior to initialization.  Add a test of
!selinux_initialized(state) to all of the exported functions that
were missing them and handle appropriately.

Fixes: 461698026ffa ("selinux: encapsulate policy state, refactor policy load")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-19 21:14:41 -04:00
Colin Ian King
69ea651c40 selinux: fix allocation failure check on newpolicy->sidtab
The allocation check of newpolicy->sidtab is null checking if
newpolicy is null and not newpolicy->sidtab. Fix this.

Addresses-Coverity: ("Logically dead code")
Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-19 09:14:04 -04:00
Stephen Smalley
c7c556f1e8 selinux: refactor changing booleans
Refactor the logic for changing SELinux policy booleans in a similar
manner to the refactoring of policy load, thereby reducing the
size of the critical section when the policy write-lock is held
and making it easier to convert the policy rwlock to RCU in the
future.  Instead of directly modifying the policydb in place, modify
a copy and then swap it into place through a single pointer update.
Only fully copy the portions of the policydb that are affected by
boolean changes to avoid the full cost of a deep policydb copy.
Introduce another level of indirection for the sidtab since changing
booleans does not require updating the sidtab, unlike policy load.
While we are here, create a common helper for notifying
other kernel components and userspace of a policy change and call it
from both security_set_bools() and selinux_policy_commit().

Based on an old (2004) patch by Kaigai Kohei [1] to convert the policy
rwlock to RCU that was deferred at the time since it did not
significantly improve performance and introduced complexity. Peter
Enderborg later submitted a patch series to convert to RCU [2] that
would have made changing booleans a much more expensive operation
by requiring a full policydb_write();policydb_read(); sequence to
deep copy the entire policydb and also had concerns regarding
atomic allocations.

This change is now simplified by the earlier work to encapsulate
policy state in the selinux_policy struct and to refactor
policy load.  After this change, the last major obstacle to
converting the policy rwlock to RCU is likely the sidtab live
convert support.

[1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/
[2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17 21:00:33 -04:00
Stephen Smalley
02a52c5c8c selinux: move policy commit after updating selinuxfs
With the refactoring of the policy load logic in the security
server from the previous change, it is now possible to split out
the committing of the new policy from security_load_policy() and
perform it only after successful updating of selinuxfs.  Change
security_load_policy() to return the newly populated policy
data structures to the caller, export selinux_policy_commit()
for external callers, and introduce selinux_policy_cancel() to
provide a way to cancel the policy load in the event of an error
during updating of the selinuxfs directory tree.  Further, rework
the interfaces used by selinuxfs to get information from the policy
when creating the new directory tree to take and act upon the
new policy data structure rather than the current/active policy.
Update selinuxfs to use these updated and new interfaces.  While
we are here, stop re-creating the policy_capabilities directory
on each policy load since it does not depend on the policy, and
stop trying to create the booleans and classes directories during
the initial creation of selinuxfs since no information is available
until first policy load.

After this change, a failure while updating the booleans and class
directories will cause the entire policy load to be canceled, leaving
the original policy intact, and policy load notifications to userspace
will only happen after a successful completion of updating those
directories.  This does not (yet) provide full atomicity with respect
to the updating of the directory trees themselves.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17 20:50:22 -04:00
Stephen Smalley
461698026f selinux: encapsulate policy state, refactor policy load
Encapsulate the policy state in its own structure (struct
selinux_policy) that is separately allocated but referenced from the
selinux_ss structure.  The policy state includes the SID table
(particularly the context structures), the policy database, and the
mapping between the kernel classes/permissions and the policy values.
Refactor the security server portion of the policy load logic to
cleanly separate loading of the new structures from committing the new
policy.  Unify the initial policy load and reload code paths as much
as possible, avoiding duplicated code.  Make sure we are taking the
policy read-lock prior to any dereferencing of the policy.  Move the
copying of the policy capability booleans into the state structure
outside of the policy write-lock because they are separate from the
policy and are read outside of any policy lock; possibly they should
be using at least READ_ONCE/WRITE_ONCE or smp_load_acquire/store_release.

These changes simplify the policy loading logic, reduce the size of
the critical section while holding the policy write-lock, and should
facilitate future changes to e.g. refactor the entire policy reload
logic including the selinuxfs code to make the updating of the policy
and the selinuxfs directory tree atomic and/or to convert the policy
read-write lock to RCU.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17 20:48:57 -04:00
Stephen Smalley
339949be25 scripts/selinux,selinux: update mdp to enable policy capabilities
Presently mdp does not enable any SELinux policy capabilities
in the dummy policy it generates. Thus, policies derived from
it will by default lack various features commonly used in modern
policies such as open permission, extended socket classes, network
peer controls, etc.  Split the policy capability definitions out into
their own headers so that we can include them into mdp without pulling in
other kernel headers and extend mdp generate policycap statements for the
policy capabilities known to the kernel.  Policy authors may wish to
selectively remove some of these from the generated policy.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17 20:42:00 -04:00
Linus Torvalds
9ad57f6dfc Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction,
   mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util,
   memory-hotplug, cleanups, uaccess, migration, gup, pagemap),

 - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops,
   checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump,
   exec, kdump, rapidio, panic, kcov, kgdb, ipc).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits)
  mm/gup: remove task_struct pointer for all gup code
  mm: clean up the last pieces of page fault accountings
  mm/xtensa: use general page fault accounting
  mm/x86: use general page fault accounting
  mm/sparc64: use general page fault accounting
  mm/sparc32: use general page fault accounting
  mm/sh: use general page fault accounting
  mm/s390: use general page fault accounting
  mm/riscv: use general page fault accounting
  mm/powerpc: use general page fault accounting
  mm/parisc: use general page fault accounting
  mm/openrisc: use general page fault accounting
  mm/nios2: use general page fault accounting
  mm/nds32: use general page fault accounting
  mm/mips: use general page fault accounting
  mm/microblaze: use general page fault accounting
  mm/m68k: use general page fault accounting
  mm/ia64: use general page fault accounting
  mm/hexagon: use general page fault accounting
  mm/csky: use general page fault accounting
  ...
2020-08-12 11:24:12 -07:00
Peter Xu
64019a2e46 mm/gup: remove task_struct pointer for all gup code
After the cleanup of page fault accounting, gup does not need to pass
task_struct around any more.  Remove that parameter in the whole gup
stack.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:58:04 -07:00
Linus Torvalds
ce13266d97 Minor fixes for v5.9.
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Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "A couple of minor documentation updates only for this release"

* tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: drop duplicated words in header file comments
  Replace HTTP links with HTTPS ones: security
2020-08-11 14:30:36 -07:00
Waiman Long
453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00