Commit Graph

588 Commits

Author SHA1 Message Date
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
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
Alexander A. Klimov c9fecf505a Replace HTTP links with HTTPS ones: security
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2020-08-06 12:00:05 -07:00
Richard Guy Briggs f1d9b23cab audit: purge audit_log_string from the intra-kernel audit API
audit_log_string() was inteded to be an internal audit function and
since there are only two internal uses, remove them.  Purge all external
uses of it by restructuring code to use an existing audit_log_format()
or using audit_log_format().

Please see the upstream issue
https://github.com/linux-audit/audit-kernel/issues/84

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21 11:12:31 -04:00
Linus Torvalds 595a56ac1b linux-kselftest-kunit-5.8-rc1
This Kunit update for Linux 5.8-rc1 consists of:
 
 - Several config fragment fixes from Anders Roxell to improve
   test coverage.
 - Improvements to kunit run script to use defconfig as default and
   restructure the code for config/build/exec/parse from Vitor Massaru Iha
   and David Gow.
 - Miscellaneous documentation warn fix.
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Merge tag 'linux-kselftest-kunit-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kunit updates from Shuah Khan:
 "This consists of:

   - Several config fragment fixes from Anders Roxell to improve test
     coverage.

   - Improvements to kunit run script to use defconfig as default and
     restructure the code for config/build/exec/parse from Vitor Massaru
     Iha and David Gow.

   - Miscellaneous documentation warn fix"

* tag 'linux-kselftest-kunit-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  security: apparmor: default KUNIT_* fragments to KUNIT_ALL_TESTS
  fs: ext4: default KUNIT_* fragments to KUNIT_ALL_TESTS
  drivers: base: default KUNIT_* fragments to KUNIT_ALL_TESTS
  lib: Kconfig.debug: default KUNIT_* fragments to KUNIT_ALL_TESTS
  kunit: default KUNIT_* fragments to KUNIT_ALL_TESTS
  kunit: Kconfig: enable a KUNIT_ALL_TESTS fragment
  kunit: Fix TabError, remove defconfig code and handle when there is no kunitconfig
  kunit: use KUnit defconfig by default
  kunit: use --build_dir=.kunit as default
  Documentation: test.h - fix warnings
  kunit: kunit_tool: Separate out config/build/exec/parse
2020-06-09 10:04:47 -07:00
Linus Torvalds a2b447066c Tag summary
+ Features
   - Replace zero-length array with flexible-array
   - add a valid state flags check
   - add consistency check between state and dfa diff encode flags
   - add apparmor subdir to proc attr interface
   - fail unpack if profile mode is unknown
   - add outofband transition and use it in xattr match
   - ensure that dfa state tables have entries
 
 + Cleanups
   - Use true and false for bool variable
   - Remove semicolon
   - Clean code by removing redundant instructions
   - Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
   - remove duplicate check of xattrs on profile attachment
   - remove useless aafs_create_symlink
 
 + Bug fixes
   - Fix memory leak of profile proxy
   - fix introspection of of task mode for unconfined tasks
   - fix nnp subset test for unconfined
   - check/put label on apparmor_sk_clone_security()
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Merge tag 'apparmor-pr-2020-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:
   - Replace zero-length array with flexible-array
   - add a valid state flags check
   - add consistency check between state and dfa diff encode flags
   - add apparmor subdir to proc attr interface
   - fail unpack if profile mode is unknown
   - add outofband transition and use it in xattr match
   - ensure that dfa state tables have entries

  Cleanups:
   - Use true and false for bool variable
   - Remove semicolon
   - Clean code by removing redundant instructions
   - Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
   - remove duplicate check of xattrs on profile attachment
   - remove useless aafs_create_symlink

  Bug fixes:
   - Fix memory leak of profile proxy
   - fix introspection of of task mode for unconfined tasks
   - fix nnp subset test for unconfined
   - check/put label on apparmor_sk_clone_security()"

* tag 'apparmor-pr-2020-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: Fix memory leak of profile proxy
  apparmor: fix introspection of of task mode for unconfined tasks
  apparmor: check/put label on apparmor_sk_clone_security()
  apparmor: Use true and false for bool variable
  security/apparmor/label.c: Clean code by removing redundant instructions
  apparmor: Replace zero-length array with flexible-array
  apparmor: ensure that dfa state tables have entries
  apparmor: remove duplicate check of xattrs on profile attachment.
  apparmor: add outofband transition and use it in xattr match
  apparmor: fail unpack if profile mode is unknown
  apparmor: fix nnp subset test for unconfined
  apparmor: remove useless aafs_create_symlink
  apparmor: add proc subdir to attrs
  apparmor: add consistency check between state and dfa diff encode flags
  apparmor: add a valid state flags check
  AppArmor: Remove semicolon
  apparmor: Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
2020-06-07 16:04:49 -07:00
John Johansen 3622ad25d4 apparmor: Fix memory leak of profile proxy
When the proxy isn't replaced and the profile is removed, the proxy
is being leaked resulting in a kmemleak check message of

unreferenced object 0xffff888077a3a490 (size 16):
  comm "apparmor_parser", pid 128041, jiffies 4322684109 (age 1097.028s)
  hex dump (first 16 bytes):
    03 00 00 00 00 00 00 00 b0 92 fd 4b 81 88 ff ff  ...........K....
  backtrace:
    [<0000000084d5daf2>] aa_alloc_proxy+0x58/0xe0
    [<00000000ecc0e21a>] aa_alloc_profile+0x159/0x1a0
    [<000000004cc9ce15>] unpack_profile+0x275/0x1c40
    [<000000007332b3ca>] aa_unpack+0x1e7/0x7e0
    [<00000000e25e31bd>] aa_replace_profiles+0x18a/0x1d10
    [<00000000350d9415>] policy_update+0x237/0x650
    [<000000003fbf934e>] profile_load+0x122/0x160
    [<0000000047f7b781>] vfs_write+0x139/0x290
    [<000000008ad12358>] ksys_write+0xcd/0x170
    [<000000001a9daa7b>] do_syscall_64+0x70/0x310
    [<00000000b9efb0cf>] entry_SYSCALL_64_after_hwframe+0x49/0xb3

Make sure to cleanup the profile's embedded label which will result
on the proxy being properly freed.

Fixes: 637f688dc3 ("apparmor: switch from profiles to using labels on contexts")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-06-07 13:38:55 -07:00
John Johansen dd2569fbb0 apparmor: fix introspection of of task mode for unconfined tasks
Fix two issues with introspecting the task mode.

1. If a task is attached to a unconfined profile that is not the
   ns->unconfined profile then. Mode the mode is always reported
   as -

      $ ps -Z
      LABEL                               PID TTY          TIME CMD
      unconfined                         1287 pts/0    00:00:01 bash
      test (-)                           1892 pts/0    00:00:00 ps

   instead of the correct value of (unconfined) as shown below

      $ ps -Z
      LABEL                               PID TTY          TIME CMD
      unconfined                         2483 pts/0    00:00:01 bash
      test (unconfined)                  3591 pts/0    00:00:00 ps

2. if a task is confined by a stack of profiles that are unconfined
   the output of label mode is again the incorrect value of (-) like
   above, instead of (unconfined). This is because the visibile
   profile count increment is skipped by the special casing of
   unconfined.

Fixes: f1bd904175 ("apparmor: add the base fns() for domain labels")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-06-07 13:38:55 -07:00
Mauricio Faria de Oliveira 3b646abc5b apparmor: check/put label on apparmor_sk_clone_security()
Currently apparmor_sk_clone_security() does not check for existing
label/peer in the 'new' struct sock; it just overwrites it, if any
(with another reference to the label of the source sock.)

    static void apparmor_sk_clone_security(const struct sock *sk,
                                           struct sock *newsk)
    {
            struct aa_sk_ctx *ctx = SK_CTX(sk);
            struct aa_sk_ctx *new = SK_CTX(newsk);

            new->label = aa_get_label(ctx->label);
            new->peer = aa_get_label(ctx->peer);
    }

This might leak label references, which might overflow under load.
Thus, check for and put labels, to prevent such errors.

Note this is similarly done on:

    static int apparmor_socket_post_create(struct socket *sock, ...)
    ...
            if (sock->sk) {
                    struct aa_sk_ctx *ctx = SK_CTX(sock->sk);

                    aa_put_label(ctx->label);
                    ctx->label = aa_get_label(label);
            }
    ...

Context:
-------

The label reference count leak is observed if apparmor_sock_graft()
is called previously: this sets the 'ctx->label' field by getting
a reference to the current label (later overwritten, without put.)

    static void apparmor_sock_graft(struct sock *sk, ...)
    {
            struct aa_sk_ctx *ctx = SK_CTX(sk);

            if (!ctx->label)
                    ctx->label = aa_get_current_label();
    }

And that is the case on crypto/af_alg.c:af_alg_accept():

    int af_alg_accept(struct sock *sk, struct socket *newsock, ...)
    ...
            struct sock *sk2;
            ...
            sk2 = sk_alloc(...);
            ...
            security_sock_graft(sk2, newsock);
            security_sk_clone(sk, sk2);
    ...

Apparently both calls are done on their own right, especially for
other LSMs, being introduced in 2010/2014, before apparmor socket
mediation in 2017 (see commits [1,2,3,4]).

So, it looks OK there! Let's fix the reference leak in apparmor.

Test-case:
---------

Exercise that code path enough to overflow label reference count.

    $ cat aa-refcnt-af_alg.c
    #include <stdio.h>
    #include <string.h>
    #include <unistd.h>
    #include <sys/socket.h>
    #include <linux/if_alg.h>

    int main() {
            int sockfd;
            struct sockaddr_alg sa;

            /* Setup the crypto API socket */
            sockfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            if (sockfd < 0) {
                    perror("socket");
                    return 1;
            }

            memset(&sa, 0, sizeof(sa));
            sa.salg_family = AF_ALG;
            strcpy((char *) sa.salg_type, "rng");
            strcpy((char *) sa.salg_name, "stdrng");

            if (bind(sockfd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
                    perror("bind");
                    return 1;
            }

            /* Accept a "connection" and close it; repeat. */
            while (!close(accept(sockfd, NULL, 0)));

            return 0;
    }

    $ gcc -o aa-refcnt-af_alg aa-refcnt-af_alg.c

    $ ./aa-refcnt-af_alg
    <a few hours later>

    [ 9928.475953] refcount_t overflow at apparmor_sk_clone_security+0x37/0x70 in aa-refcnt-af_alg[1322], uid/euid: 1000/1000
    ...
    [ 9928.507443] RIP: 0010:apparmor_sk_clone_security+0x37/0x70
    ...
    [ 9928.514286]  security_sk_clone+0x33/0x50
    [ 9928.514807]  af_alg_accept+0x81/0x1c0 [af_alg]
    [ 9928.516091]  alg_accept+0x15/0x20 [af_alg]
    [ 9928.516682]  SYSC_accept4+0xff/0x210
    [ 9928.519609]  SyS_accept+0x10/0x20
    [ 9928.520190]  do_syscall_64+0x73/0x130
    [ 9928.520808]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Note that other messages may be seen, not just overflow, depending on
the value being incremented by kref_get(); on another run:

    [ 7273.182666] refcount_t: saturated; leaking memory.
    ...
    [ 7273.185789] refcount_t: underflow; use-after-free.

Kprobes:
-------

Using kprobe events to monitor sk -> sk_security -> label -> count (kref):

Original v5.7 (one reference leak every iteration)

 ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd2
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4
 ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd3
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd5
 ... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd6

Patched v5.7 (zero reference leak per iteration)

 ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594
 ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594
 ... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
 ... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594

Commits:
-------

[1] commit 507cad355f ("crypto: af_alg - Make sure sk_security is initialized on accept()ed sockets")
[2] commit 4c63f83c2c ("crypto: af_alg - properly label AF_ALG socket")
[3] commit 2acce6aa9f ("Networking") a.k.a ("crypto: af_alg - Avoid sock_graft call warning)
[4] commit 56974a6fcf ("apparmor: add base infastructure for socket mediation")

Fixes: 56974a6fcf ("apparmor: add base infastructure for socket mediation")
Reported-by: Brian Moyles <bmoyles@netflix.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-06-07 13:38:56 -07:00
Linus Torvalds 15a2bc4dbb Merge branch 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull execve updates from Eric Biederman:
 "Last cycle for the Nth time I ran into bugs and quality of
  implementation issues related to exec that could not be easily be
  fixed because of the way exec is implemented. So I have been digging
  into exec and cleanup up what I can.

  I don't think I have exec sorted out enough to fix the issues I
  started with but I have made some headway this cycle with 4 sets of
  changes.

   - promised cleanups after introducing exec_update_mutex

   - trivial cleanups for exec

   - control flow simplifications

   - remove the recomputation of bprm->cred

  The net result is code that is a bit easier to understand and work
  with and a decrease in the number of lines of code (if you don't count
  the added tests)"

* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (24 commits)
  exec: Compute file based creds only once
  exec: Add a per bprm->file version of per_clear
  binfmt_elf_fdpic: fix execfd build regression
  selftests/exec: Add binfmt_script regression test
  exec: Remove recursion from search_binary_handler
  exec: Generic execfd support
  exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC
  exec: Move the call of prepare_binprm into search_binary_handler
  exec: Allow load_misc_binary to call prepare_binprm unconditionally
  exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds
  exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
  exec: Teach prepare_exec_creds how exec treats uids & gids
  exec: Set the point of no return sooner
  exec: Move handling of the point of no return to the top level
  exec: Run sync_mm_rss before taking exec_update_mutex
  exec: Fix spelling of search_binary_handler in a comment
  exec: Move the comment from above de_thread to above unshare_sighand
  exec: Rename flush_old_exec begin_new_exec
  exec: Move most of setup_new_exec into flush_old_exec
  exec: In setup_new_exec cache current in the local variable me
  ...
2020-06-04 14:07:08 -07:00
Anders Roxell 6d6861d45e security: apparmor: default KUNIT_* fragments to KUNIT_ALL_TESTS
This makes it easier to enable all KUnit fragments.

Adding 'if !KUNIT_ALL_TESTS' so individual tests can not be turned off.
Therefore if KUNIT_ALL_TESTS is enabled that will hide the prompt in
menuconfig.

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-06-01 14:25:15 -06:00
David S. Miller 13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Navid Emamdoost c54d481d71 apparmor: Fix use-after-free in aa_audit_rule_init
In the implementation of aa_audit_rule_init(), when aa_label_parse()
fails the allocated memory for rule is released using
aa_audit_rule_free(). But after this release, the return statement
tries to access the label field of the rule which results in
use-after-free. Before releasing the rule, copy errNo and return it
after release.

Fixes: 52e8c38001 ("apparmor: Fix memory leak of rule on error exit path")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21 15:25:51 -07:00
Xiyu Yang c6b39f0707 apparmor: Fix aa_label refcnt leak in policy_update
policy_update() invokes begin_current_label_crit_section(), which
returns a reference of the updated aa_label object to "label" with
increased refcount.

When policy_update() returns, "label" becomes invalid, so the refcount
should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
policy_update(). When aa_may_manage_policy() returns not NULL, the
refcnt increased by begin_current_label_crit_section() is not decreased,
causing a refcnt leak.

Fix this issue by jumping to "end_section" label when
aa_may_manage_policy() returns not NULL.

Fixes: 5ac8c355ae ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21 15:25:51 -07:00
Xiyu Yang a0b845ffa0 apparmor: fix potential label refcnt leak in aa_change_profile
aa_change_profile() invokes aa_get_current_label(), which returns
a reference of the current task's label.

According to the comment of aa_get_current_label(), the returned
reference must be put with aa_put_label().
However, when the original object pointed by "label" becomes
unreachable because aa_change_profile() returns or a new object
is assigned to "label", reference count increased by
aa_get_current_label() is not decreased, causing a refcnt leak.

Fix this by calling aa_put_label() before aa_change_profile() return
and dropping unnecessary aa_get_current_label().

Fixes: 9fcf78cca1 ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21 15:25:51 -07:00
Eric W. Biederman b8bff59926 exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
Today security_bprm_set_creds has several implementations:
apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds,
smack_bprm_set_creds, and tomoyo_bprm_set_creds.

Except for cap_bprm_set_creds they all test bprm->called_set_creds and
return immediately if it is true.  The function cap_bprm_set_creds
ignores bprm->calld_sed_creds entirely.

Create a new LSM hook security_bprm_creds_for_exec that is called just
before prepare_binprm in __do_execve_file, resulting in a LSM hook
that is called exactly once for the entire of exec.  Modify the bits
of security_bprm_set_creds that only want to be called once per exec
into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds
behind.

Remove bprm->called_set_creds all of it's former users have been moved
to security_bprm_creds_for_exec.

Add or upate comments a appropriate to bring them up to date and
to reflect this change.

Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-20 14:45:31 -05:00
Zou Wei e37986097b apparmor: Use true and false for bool variable
Fixes coccicheck warnings:

security/apparmor/file.c:162:9-10: WARNING: return of 0/1 in function 'is_deleted' with return type bool
security/apparmor/file.c:362:9-10: WARNING: return of 0/1 in function 'xindex_is_subset' with return type bool
security/apparmor/policy_unpack.c:246:9-10: WARNING: return of 0/1 in function 'unpack_X' with return type bool
security/apparmor/policy_unpack.c:292:9-10: WARNING: return of 0/1 in function 'unpack_nameX' with return type bool
security/apparmor/policy_unpack.c:646:8-9: WARNING: return of 0/1 in function 'unpack_rlimits' with return type bool
security/apparmor/policy_unpack.c:604:8-9: WARNING: return of 0/1 in function 'unpack_secmark' with return type bool
security/apparmor/policy_unpack.c:538:8-9: WARNING: return of 0/1 in function 'unpack_trans_table' with return type bool
security/apparmor/policy_unpack.c:327:9-10: WARNING: return of 0/1 in function 'unpack_u32' with return type bool
security/apparmor/policy_unpack.c:345:9-10: WARNING: return of 0/1 in function 'unpack_u64' with return type bool
security/apparmor/policy_unpack.c:309:9-10: WARNING: return of 0/1 in function 'unpack_u8' with return type bool
security/apparmor/policy_unpack.c:568:8-9: WARNING: return of 0/1 in function 'unpack_xattrs' with return type bool
security/apparmor/policy_unpack.c:1007:10-11: WARNING: return of 0/1 in function 'verify_dfa_xindex' with return type bool
security/apparmor/policy_unpack.c:997:9-10: WARNING: return of 0/1 in function 'verify_xindex' with return type bool

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15 14:26:33 -07:00
Mateusz Nosek c84b80cd41 security/apparmor/label.c: Clean code by removing redundant instructions
Previously 'label->proxy->label' value checking
and conditional reassigning were done twice in the same function.
The second one is redundant and can be removed.

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15 14:22:40 -07:00
Gustavo A. R. Silva fe9fd23e3b apparmor: Replace zero-length array with flexible-array
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15 13:04:55 -07:00
Christoph Hellwig 32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
John Johansen c27c6bd2c4 apparmor: ensure that dfa state tables have entries
Currently it is possible to specify a state machine table with 0 length,
this is not valid as optional tables are specified by not defining
the table as present. Further this allows by-passing the base tables
range check against the next/check tables.

Fixes: d901d6a298 ("apparmor: dfa split verification of table headers")
Reported-by: Mike Salvatore <mike.salvatore@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-04-08 04:42:48 -07:00
Masahiro Yamada d198b34f38 .gitignore: add SPDX License Identifier
Add SPDX License Identifier to all .gitignore files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 11:50:48 +01:00
Masahiro Yamada 2985bed680 .gitignore: remove too obvious comments
Some .gitignore files have comments like "Generated files",
"Ignore generated files" at the header part, but they are
too obvious.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 11:50:28 +01:00
Linus Torvalds 08a3ef8f6b linux-kselftest-5.6-rc1-kunit
This kunit update for Linux 5.6-rc1 consists of:
 
 -- Support for building kunit as a module from Alan Maguire
 -- AppArmor KUnit tests for policy unpack from Mike Salvatore
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Merge tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest kunit updates from Shuah Khan:
 "This kunit update consists of:

   - Support for building kunit as a module from Alan Maguire

   - AppArmor KUnit tests for policy unpack from Mike Salvatore"

* tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: building kunit as a module breaks allmodconfig
  kunit: update documentation to describe module-based build
  kunit: allow kunit to be loaded as a module
  kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
  kunit: allow kunit tests to be loaded as a module
  kunit: hide unexported try-catch interface in try-catch-impl.h
  kunit: move string-stream.h to lib/kunit
  apparmor: add AppArmor KUnit tests for policy unpack
2020-01-29 15:25:34 -08:00
Linus Torvalds 6aee4badd8 Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull openat2 support from Al Viro:
 "This is the openat2() series from Aleksa Sarai.

  I'm afraid that the rest of namei stuff will have to wait - it got
  zero review the last time I'd posted #work.namei, and there had been a
  leak in the posted series I'd caught only last weekend. I was going to
  repost it on Monday, but the window opened and the odds of getting any
  review during that... Oh, well.

  Anyway, openat2 part should be ready; that _did_ get sane amount of
  review and public testing, so here it comes"

From Aleksa's description of the series:
 "For a very long time, extending openat(2) with new features has been
  incredibly frustrating. This stems from the fact that openat(2) is
  possibly the most famous counter-example to the mantra "don't silently
  accept garbage from userspace" -- it doesn't check whether unknown
  flags are present[1].

  This means that (generally) the addition of new flags to openat(2) has
  been fraught with backwards-compatibility issues (O_TMPFILE has to be
  defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old
  kernels gave errors, since it's insecure to silently ignore the
  flag[2]). All new security-related flags therefore have a tough road
  to being added to openat(2).

  Furthermore, the need for some sort of control over VFS's path
  resolution (to avoid malicious paths resulting in inadvertent
  breakouts) has been a very long-standing desire of many userspace
  applications.

  This patchset is a revival of Al Viro's old AT_NO_JUMPS[3] patchset
  (which was a variant of David Drysdale's O_BENEATH patchset[4] which
  was a spin-off of the Capsicum project[5]) with a few additions and
  changes made based on the previous discussion within [6] as well as
  others I felt were useful.

  In line with the conclusions of the original discussion of
  AT_NO_JUMPS, the flag has been split up into separate flags. However,
  instead of being an openat(2) flag it is provided through a new
  syscall openat2(2) which provides several other improvements to the
  openat(2) interface (see the patch description for more details). The
  following new LOOKUP_* flags are added:

  LOOKUP_NO_XDEV:

     Blocks all mountpoint crossings (upwards, downwards, or through
     absolute links). Absolute pathnames alone in openat(2) do not
     trigger this. Magic-link traversal which implies a vfsmount jump is
     also blocked (though magic-link jumps on the same vfsmount are
     permitted).

  LOOKUP_NO_MAGICLINKS:

     Blocks resolution through /proc/$pid/fd-style links. This is done
     by blocking the usage of nd_jump_link() during resolution in a
     filesystem. The term "magic-links" is used to match with the only
     reference to these links in Documentation/, but I'm happy to change
     the name.

     It should be noted that this is different to the scope of
     ~LOOKUP_FOLLOW in that it applies to all path components. However,
     you can do openat2(NO_FOLLOW|NO_MAGICLINKS) on a magic-link and it
     will *not* fail (assuming that no parent component was a
     magic-link), and you will have an fd for the magic-link.

     In order to correctly detect magic-links, the introduction of a new
     LOOKUP_MAGICLINK_JUMPED state flag was required.

  LOOKUP_BENEATH:

     Disallows escapes to outside the starting dirfd's
     tree, using techniques such as ".." or absolute links. Absolute
     paths in openat(2) are also disallowed.

     Conceptually this flag is to ensure you "stay below" a certain
     point in the filesystem tree -- but this requires some additional
     to protect against various races that would allow escape using
     "..".

     Currently LOOKUP_BENEATH implies LOOKUP_NO_MAGICLINKS, because it
     can trivially beam you around the filesystem (breaking the
     protection). In future, there might be similar safety checks done
     as in LOOKUP_IN_ROOT, but that requires more discussion.

  In addition, two new flags are added that expand on the above ideas:

  LOOKUP_NO_SYMLINKS:

     Does what it says on the tin. No symlink resolution is allowed at
     all, including magic-links. Just as with LOOKUP_NO_MAGICLINKS this
     can still be used with NOFOLLOW to open an fd for the symlink as
     long as no parent path had a symlink component.

  LOOKUP_IN_ROOT:

     This is an extension of LOOKUP_BENEATH that, rather than blocking
     attempts to move past the root, forces all such movements to be
     scoped to the starting point. This provides chroot(2)-like
     protection but without the cost of a chroot(2) for each filesystem
     operation, as well as being safe against race attacks that
     chroot(2) is not.

     If a race is detected (as with LOOKUP_BENEATH) then an error is
     generated, and similar to LOOKUP_BENEATH it is not permitted to
     cross magic-links with LOOKUP_IN_ROOT.

     The primary need for this is from container runtimes, which
     currently need to do symlink scoping in userspace[7] when opening
     paths in a potentially malicious container.

     There is a long list of CVEs that could have bene mitigated by
     having RESOLVE_THIS_ROOT (such as CVE-2017-1002101,
     CVE-2017-1002102, CVE-2018-15664, and CVE-2019-5736, just to name a
     few).

  In order to make all of the above more usable, I'm working on
  libpathrs[8] which is a C-friendly library for safe path resolution.
  It features a userspace-emulated backend if the kernel doesn't support
  openat2(2). Hopefully we can get userspace to switch to using it, and
  thus get openat2(2) support for free once it's ready.

  Future work would include implementing things like
  RESOLVE_NO_AUTOMOUNT and possibly a RESOLVE_NO_REMOTE (to allow
  programs to be sure they don't hit DoSes though stale NFS handles)"

* 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Documentation: path-lookup: include new LOOKUP flags
  selftests: add openat2(2) selftests
  open: introduce openat2(2) syscall
  namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
  namei: LOOKUP_IN_ROOT: chroot-like scoped resolution
  namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution
  namei: LOOKUP_NO_XDEV: block mountpoint crossing
  namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution
  namei: LOOKUP_NO_SYMLINKS: block symlink resolution
  namei: allow set_root() to produce errors
  namei: allow nd_jump_link() to produce errors
  nsfs: clean-up ns_get_path() signature to return int
  namei: only return -ECHILD from follow_dotdot_rcu()
2020-01-29 11:20:24 -08:00
John Johansen 01df52d726 apparmor: remove duplicate check of xattrs on profile attachment.
The second check to ensure the xattrs are present and checked is
unneeded as this is already done in the profile attachment xmatch.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 06:00:20 -08:00
John Johansen 0df34a645b apparmor: add outofband transition and use it in xattr match
There are cases where the a special out of band transition that can
not be triggered by input is useful in separating match conditions
in the dfa encoding.

The null_transition is currently used as an out of band transition
for match conditions that can not contain a \0 in their input
but apparmor needs an out of band transition for cases where
the match condition is allowed to contain any input character.

Achieve this by allowing for an explicit transition out of input
range that can only be triggered by code.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 06:00:20 -08:00
John Johansen f05841a940 apparmor: fail unpack if profile mode is unknown
Profile unpack should fail if the profile mode is not a mode that the
kernel understands.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 05:58:53 -08:00
John Johansen 3ed4aaa94f apparmor: fix nnp subset test for unconfined
The subset test is not taking into account the unconfined exception
which will cause profile transitions in the stacked confinement
case to fail when no_new_privs is applied.

This fixes a regression introduced in the fix for
https://bugs.launchpad.net/bugs/1839037

BugLink: https://bugs.launchpad.net/bugs/1844186
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 05:58:04 -08:00
John Johansen a68d59ff4d apparmor: remove useless aafs_create_symlink
commit 1180b4c757 ("apparmor: fix dangling symlinks to policy
rawdata after replacement") reworked how the rawdata symlink is
handled but failedto remove aafs_create_symlink which was reduced to a
useles stub.

Fixes: 1180b4c757 ("apparmor: fix dangling symlinks to policy rawdata after replacement")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-21 05:55:38 -08:00
John Johansen dae6029325 apparmor: add consistency check between state and dfa diff encode flags
Check that a states diff encode flag is only set if diff encode is
enabled in the dfa header.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-18 15:37:49 -08:00
John Johansen c659696964 apparmor: add a valid state flags check
Add a check to ensure only known state flags are set on each
state in the dfa.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-18 15:37:24 -08:00
Vasyl Gomonovych e4f4e6ba5e AppArmor: Remove semicolon
Remove unneeded semicolon

Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-18 15:36:58 -08:00
Markus Elfring 278de07ef8 apparmor: Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
Two strings which did not contain a data format specification should be put
into a sequence. Thus use the corresponding function “seq_puts”.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-18 15:35:23 -08:00
Alan Maguire 35c57fc3f8 kunit: building kunit as a module breaks allmodconfig
kunit tests that do not support module build should depend
on KUNIT=y rather than just KUNIT in Kconfig, otherwise
they will trigger compilation errors for "make allmodconfig"
builds.

Fixes: 9fe124bf1b ("kunit: allow kunit to be loaded as a module")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-10 14:36:37 -07:00
Mike Salvatore 4d944bcd4e apparmor: add AppArmor KUnit tests for policy unpack
Add KUnit tests to test AppArmor unpacking of userspace policies.
AppArmor uses a serialized binary format for loading policies. To find
policy format documentation see
Documentation/admin-guide/LSM/apparmor.rst.

In order to write the tests against the policy unpacking code, some
static functions needed to be exposed for testing purposes. One of the
goals of this patch is to establish a pattern for which testing these
kinds of functions should be done in the future.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-09 16:27:43 -07:00
John Johansen 8c62ed27a1 apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock
aa_xattrs_match() is unfortunately calling vfs_getxattr_alloc() from a
context protected by an rcu_read_lock. This can not be done as
vfs_getxattr_alloc() may sleep regardles of the gfp_t value being
passed to it.

Fix this by breaking the rcu_read_lock on the policy search when the
xattr match feature is requested and restarting the search if a policy
changes occur.

Fixes: 8e51f9087f ("apparmor: Add support for attaching profiles via xattr, presence and value")
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-04 15:56:44 -08:00
John Johansen 20d4e80d25 apparmor: only get a label reference if the fast path check fails
The common fast path check can be done under rcu_read_lock() and
doesn't need a reference count on the label. Only take a reference
count if entering the slow path.

Fixes reported hackbench regression
  - sha1 79e178a57d ("Merge tag 'apparmor-pr-2019-12-03' of
    git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor")

  hackbench -l (256000/#grp) -g #grp
   128 groups     19.679 ±0.90%

  - previous sha1 01d1dff646 ("Merge tag 's390-5.5-2' of
    git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")

  hackbench -l (256000/#grp) -g #grp
   128 groups     3.1689 ±3.04%

Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: bce4e7e9c4 ("apparmor: reduce rcu_read_lock scope for aa_file_perm mediation")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-02 05:31:40 -08:00
Patrick Steinhardt 9c95a278ba apparmor: fix bind mounts aborting with -ENOMEM
With commit df323337e5 ("apparmor: Use a memory pool instead per-CPU
caches, 2019-05-03"), AppArmor code was converted to use memory pools. In
that conversion, a bug snuck into the code that polices bind mounts that
causes all bind mounts to fail with -ENOMEM, as we erroneously error out
if `aa_get_buffer` returns a pointer instead of erroring out when it
does _not_ return a valid pointer.

Fix the issue by correctly checking for valid pointers returned by
`aa_get_buffer` to fix bind mounts with AppArmor.

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-01-02 05:31:40 -08:00
Aleksa Sarai 1bc82070fa namei: allow nd_jump_link() to produce errors
In preparation for LOOKUP_NO_MAGICLINKS, it's necessary to add the
ability for nd_jump_link() to return an error which the corresponding
get_link() caller must propogate back up to the VFS.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-08 19:09:38 -05:00
Linus Torvalds 79e178a57d + Features
- increase left match history buffer size to provide inproved conflict
     resolution in overlapping execution rules.
   - switch buffer allocation to use a memory pool and GFP_KERNEL
     where possible.
   - add compression of policy blobs to reduce memory usage.
 + Cleanups
   - fix spelling mistake "immutible" -> "immutable"
 + Bug fixes
   - fix unsigned len comparison in update_for_len macro
   - fix sparse warning for type-casting of current->real_cred
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Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:

   - increase left match history buffer size to provide improved
     conflict resolution in overlapping execution rules.

   - switch buffer allocation to use a memory pool and GFP_KERNEL where
     possible.

   - add compression of policy blobs to reduce memory usage.

  Cleanups:

   - fix spelling mistake "immutible" -> "immutable"

  Bug fixes:

   - fix unsigned len comparison in update_for_len macro

   - fix sparse warning for type-casting of current->real_cred"

* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: make it so work buffers can be allocated from atomic context
  apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
  apparmor: fix wrong buffer allocation in aa_new_mount
  apparmor: fix unsigned len comparison with less than zero
  apparmor: increase left match history buffer size
  apparmor: Switch to GFP_KERNEL where possible
  apparmor: Use a memory pool instead per-CPU caches
  apparmor: Force type-casting of current->real_cred
  apparmor: fix spelling mistake "immutible" -> "immutable"
  apparmor: fix blob compression when ns is forced on a policy load
  apparmor: fix missing ZLIB defines
  apparmor: fix blob compression build failure on ppc
  apparmor: Initial implementation of raw policy blob compression
2019-12-03 12:51:35 -08:00
John Johansen 341c1fda5e apparmor: make it so work buffers can be allocated from atomic context
In some situations AppArmor needs to be able to use its work buffers
from atomic context. Add the ability to specify when in atomic context
and hold a set of work buffers in reserve for atomic context to
reduce the chance that a large work buffer allocation will need to
be done.

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:41:08 -08:00
John Johansen bce4e7e9c4 apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
Now that the buffers allocation has changed and no longer needs
the full mediation under an rcu_read_lock, reduce the rcu_read_lock
scope to only where it is necessary.

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:40:21 -08:00
John Johansen 8f21a62475 apparmor: fix wrong buffer allocation in aa_new_mount
Fix the following trace caused by the dev_path buffer not being
allocated.

[  641.044262] AppArmor WARN match_mnt: ((devpath && !devbuffer)):
[  641.044284] WARNING: CPU: 1 PID: 30709 at ../security/apparmor/mount.c:385 match_mnt+0x133/0x180
[  641.044286] Modules linked in: snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_hda_codec snd_hda_core qxl ttm snd_hwdep snd_pcm drm_kms_helper snd_seq_midi snd_seq_midi_event drm snd_rawmidi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iptable_mangle aesni_intel aes_x86_64 xt_tcpudp crypto_simd snd_seq cryptd bridge stp llc iptable_filter glue_helper snd_seq_device snd_timer joydev input_leds snd serio_raw fb_sys_fops 9pnet_virtio 9pnet syscopyarea sysfillrect soundcore sysimgblt qemu_fw_cfg mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 8139too psmouse 8139cp i2c_piix4 pata_acpi mii floppy
[  641.044318] CPU: 1 PID: 30709 Comm: mount Tainted: G      D W         5.1.0-rc4+ #223
[  641.044320] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  641.044323] RIP: 0010:match_mnt+0x133/0x180
[  641.044325] Code: 41 5d 41 5e 41 5f c3 48 8b 4c 24 18 eb b1 48 c7 c6 08 84 26 83 48 c7 c7 f0 56 54 83 4c 89 54 24 08 48 89 14 24 e8 7d d3 bb ff <0f> 0b 4c 8b 54 24 08 48 8b 14 24 e9 25 ff ff ff 48 c7 c6 08 84 26
[  641.044327] RSP: 0018:ffffa9b34ac97d08 EFLAGS: 00010282
[  641.044329] RAX: 0000000000000000 RBX: ffff9a86725a8558 RCX: 0000000000000000
[  641.044331] RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000246
[  641.044333] RBP: ffffa9b34ac97db0 R08: 0000000000000000 R09: 0000000000000000
[  641.044334] R10: 0000000000000000 R11: 00000000000077f5 R12: 0000000000000000
[  641.044336] R13: ffffa9b34ac97e98 R14: ffff9a865e000008 R15: ffff9a86c4cf42b8
[  641.044338] FS:  00007fab73969740(0000) GS:ffff9a86fbb00000(0000) knlGS:0000000000000000
[  641.044340] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  641.044342] CR2: 000055f90bc62035 CR3: 00000000aab5f006 CR4: 00000000003606e0
[  641.044346] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  641.044348] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  641.044349] Call Trace:
[  641.044355]  aa_new_mount+0x119/0x2c0
[  641.044363]  apparmor_sb_mount+0xd4/0x430
[  641.044367]  security_sb_mount+0x46/0x70
[  641.044372]  do_mount+0xbb/0xeb0
[  641.044377]  ? memdup_user+0x4b/0x70
[  641.044380]  ksys_mount+0x7e/0xd0
[  641.044384]  __x64_sys_mount+0x21/0x30
[  641.044388]  do_syscall_64+0x5a/0x1a0
[  641.044392]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  641.044394] RIP: 0033:0x7fab73a8790a
[  641.044397] Code: 48 8b 0d 89 85 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 85 0c 00 f7 d8 64 89 01 48
[  641.044399] RSP: 002b:00007ffe0ffe4238 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[  641.044401] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fab73a8790a
[  641.044429] RDX: 000055f90bc6203b RSI: 00007ffe0ffe57b1 RDI: 00007ffe0ffe57a5
[  641.044431] RBP: 00007ffe0ffe4250 R08: 0000000000000000 R09: 00007fab73b51d80
[  641.044433] R10: 00000000c0ed0004 R11: 0000000000000206 R12: 000055f90bc610b0
[  641.044434] R13: 00007ffe0ffe4330 R14: 0000000000000000 R15: 0000000000000000
[  641.044457] irq event stamp: 0
[  641.044460] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
[  641.044463] hardirqs last disabled at (0): [<ffffffff82290114>] copy_process.part.30+0x734/0x23f0
[  641.044467] softirqs last  enabled at (0): [<ffffffff82290114>] copy_process.part.30+0x734/0x23f0
[  641.044469] softirqs last disabled at (0): [<0000000000000000>]           (null)
[  641.044470] ---[ end trace c0d54bdacf6af6b2 ]---

Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:39:32 -08:00
Colin Ian King 00e0590dba apparmor: fix unsigned len comparison with less than zero
The sanity check in macro update_for_len checks to see if len
is less than zero, however, len is a size_t so it can never be
less than zero, so this sanity check is a no-op.  Fix this by
making len a ssize_t so the comparison will work and add ulen
that is a size_t copy of len so that the min() macro won't
throw warnings about comparing different types.

Addresses-Coverity: ("Macro compares unsigned to 0")
Fixes: f1bd904175 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-22 16:37:54 -08:00
Linus Torvalds 933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
Linus Torvalds e192832869 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "The main changes in this cycle are:

   - rwsem scalability improvements, phase #2, by Waiman Long, which are
     rather impressive:

       "On a 2-socket 40-core 80-thread Skylake system with 40 reader
        and writer locking threads, the min/mean/max locking operations
        done in a 5-second testing window before the patchset were:

         40 readers, Iterations Min/Mean/Max = 1,807/1,808/1,810
         40 writers, Iterations Min/Mean/Max = 1,807/50,344/151,255

        After the patchset, they became:

         40 readers, Iterations Min/Mean/Max = 30,057/31,359/32,741
         40 writers, Iterations Min/Mean/Max = 94,466/95,845/97,098"

     There's a lot of changes to the locking implementation that makes
     it similar to qrwlock, including owner handoff for more fair
     locking.

     Another microbenchmark shows how across the spectrum the
     improvements are:

       "With a locking microbenchmark running on 5.1 based kernel, the
        total locking rates (in kops/s) on a 2-socket Skylake system
        with equal numbers of readers and writers (mixed) before and
        after this patchset were:

        # of Threads   Before Patch      After Patch
        ------------   ------------      -----------
             2            2,618             4,193
             4            1,202             3,726
             8              802             3,622
            16              729             3,359
            32              319             2,826
            64              102             2,744"

     The changes are extensive and the patch-set has been through
     several iterations addressing various locking workloads. There
     might be more regressions, but unless they are pathological I
     believe we want to use this new implementation as the baseline
     going forward.

   - jump-label optimizations by Daniel Bristot de Oliveira: the primary
     motivation was to remove IPI disturbance of isolated RT-workload
     CPUs, which resulted in the implementation of batched jump-label
     updates. Beyond the improvement of the real-time characteristics
     kernel, in one test this patchset improved static key update
     overhead from 57 msecs to just 1.4 msecs - which is a nice speedup
     as well.

   - atomic64_t cross-arch type cleanups by Mark Rutland: over the last
     ~10 years of atomic64_t existence the various types used by the
     APIs only had to be self-consistent within each architecture -
     which means they became wildly inconsistent across architectures.
     Mark puts and end to this by reworking all the atomic64
     implementations to use 's64' as the base type for atomic64_t, and
     to ensure that this type is consistently used for parameters and
     return values in the API, avoiding further problems in this area.

   - A large set of small improvements to lockdep by Yuyang Du: type
     cleanups, output cleanups, function return type and othr cleanups
     all around the place.

   - A set of percpu ops cleanups and fixes by Peter Zijlstra.

   - Misc other changes - please see the Git log for more details"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (82 commits)
  locking/lockdep: increase size of counters for lockdep statistics
  locking/atomics: Use sed(1) instead of non-standard head(1) option
  locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING
  x86/jump_label: Make tp_vec_nr static
  x86/percpu: Optimize raw_cpu_xchg()
  x86/percpu, sched/fair: Avoid local_clock()
  x86/percpu, x86/irq: Relax {set,get}_irq_regs()
  x86/percpu: Relax smp_processor_id()
  x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}()
  locking/rwsem: Guard against making count negative
  locking/rwsem: Adaptive disabling of reader optimistic spinning
  locking/rwsem: Enable time-based spinning on reader-owned rwsem
  locking/rwsem: Make rwsem->owner an atomic_long_t
  locking/rwsem: Enable readers spinning on writer
  locking/rwsem: Clarify usage of owner's nonspinaable bit
  locking/rwsem: Wake up almost all readers in wait queue
  locking/rwsem: More optimal RT task handling of null owner
  locking/rwsem: Always release wait_lock before waking up tasks
  locking/rwsem: Implement lock handoff to prevent lock starvation
  locking/rwsem: Make rwsem_spin_on_owner() return owner state
  ...
2019-07-08 16:12:03 -07:00
David Howells b0ecc9da5f vfs: Convert apparmorfs to use the new mount API
Convert the apparmorfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: John Johansen <john.johansen@canonical.com>
cc: apparmor@lists.ubuntu.com
cc: linux-security-module@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00
John Johansen 136db99485 apparmor: increase left match history buffer size
There have been cases reported where a history buffer size of 8 was
not enough to resolve conflict overlaps. Increase the buffer to and
get rid of the size element which is currently just storing the
constant WB_HISTORY_SIZE.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-06-20 10:33:31 -07:00