<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/security/apparmor, branch v5.4.133</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.4.133</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.4.133'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2020-07-22T07:33:05Z</updated>
<entry>
<title>apparmor: ensure that dfa state tables have entries</title>
<updated>2020-07-22T07:33:05Z</updated>
<author>
<name>John Johansen</name>
<email>john.johansen@canonical.com</email>
</author>
<published>2020-03-31T06:37:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=d79e57db45444a4ea9b334fde3fc581fa4846058'/>
<id>urn:sha1:d79e57db45444a4ea9b334fde3fc581fa4846058</id>
<content type='text'>
commit c27c6bd2c4d6b6bb779f9b722d5607993e1d5e5c upstream.

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: d901d6a298dc ("apparmor: dfa split verification of table headers")
Reported-by: Mike Salvatore &lt;mike.salvatore@canonical.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>apparmor: fix nnp subset test for unconfined</title>
<updated>2020-06-24T15:50:20Z</updated>
<author>
<name>John Johansen</name>
<email>john.johansen@canonical.com</email>
</author>
<published>2019-09-25T15:02:48Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a78c65cb4b67bd77f8aa455fe63ab72ea73eba3b'/>
<id>urn:sha1:a78c65cb4b67bd77f8aa455fe63ab72ea73eba3b</id>
<content type='text'>
[ Upstream commit 3ed4aaa94fc07db3cd0c91be95e3e1b9782a2710 ]

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 &lt;john.johansen@canonical.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>apparmor: check/put label on apparmor_sk_clone_security()</title>
<updated>2020-06-24T15:50:19Z</updated>
<author>
<name>Mauricio Faria de Oliveira</name>
<email>mfo@canonical.com</email>
</author>
<published>2020-06-02T21:15:16Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=039a79ef0b1eb81ab060f29e14d3f9df0e6bc447'/>
<id>urn:sha1:039a79ef0b1eb81ab060f29e14d3f9df0e6bc447</id>
<content type='text'>
[ Upstream commit 3b646abc5bc6c0df649daea4c2c976bd4d47e4c8 ]

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-&gt;label = aa_get_label(ctx-&gt;label);
            new-&gt;peer = aa_get_label(ctx-&gt;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-&gt;sk) {
                    struct aa_sk_ctx *ctx = SK_CTX(sock-&gt;sk);

                    aa_put_label(ctx-&gt;label);
                    ctx-&gt;label = aa_get_label(label);
            }
    ...

Context:
-------

The label reference count leak is observed if apparmor_sock_graft()
is called previously: this sets the 'ctx-&gt;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-&gt;label)
                    ctx-&gt;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 &lt;stdio.h&gt;
    #include &lt;string.h&gt;
    #include &lt;unistd.h&gt;
    #include &lt;sys/socket.h&gt;
    #include &lt;linux/if_alg.h&gt;

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

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

            memset(&amp;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 *) &amp;sa, sizeof(sa)) &lt; 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
    &lt;a few hours later&gt;

    [ 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 -&gt; sk_security -&gt; label -&gt; 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 507cad355fc9 ("crypto: af_alg - Make sure sk_security is initialized on accept()ed sockets")
[2] commit 4c63f83c2c2e ("crypto: af_alg - properly label AF_ALG socket")
[3] commit 2acce6aa9f65 ("Networking") a.k.a ("crypto: af_alg - Avoid sock_graft call warning)
[4] commit 56974a6fcfef ("apparmor: add base infastructure for socket mediation")

Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket mediation")
Reported-by: Brian Moyles &lt;bmoyles@netflix.com&gt;
Signed-off-by: Mauricio Faria de Oliveira &lt;mfo@canonical.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>apparmor: fix introspection of of task mode for unconfined tasks</title>
<updated>2020-06-24T15:50:19Z</updated>
<author>
<name>John Johansen</name>
<email>john.johansen@canonical.com</email>
</author>
<published>2020-06-06T01:12:21Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=88bc3e06039035fcd63a0d52ed8625e8682b107a'/>
<id>urn:sha1:88bc3e06039035fcd63a0d52ed8625e8682b107a</id>
<content type='text'>
[ Upstream commit dd2569fbb053719f7df7ef8fdbb45cf47156a701 ]

Fix two issues with introspecting the task mode.

1. If a task is attached to a unconfined profile that is not the
   ns-&gt;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: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>apparmor: Fix aa_label refcnt leak in policy_update</title>
<updated>2020-05-27T15:46:42Z</updated>
<author>
<name>Xiyu Yang</name>
<email>xiyuyang19@fudan.edu.cn</email>
</author>
<published>2020-04-20T05:35:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=870a45e0b5078aeac097fa3242a2b40f6402e479'/>
<id>urn:sha1:870a45e0b5078aeac097fa3242a2b40f6402e479</id>
<content type='text'>
commit c6b39f070722ea9963ffe756bfe94e89218c5e63 upstream.

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: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang &lt;xiyuyang19@fudan.edu.cn&gt;
Signed-off-by: Xin Tan &lt;tanxin.ctf@gmail.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>apparmor: fix potential label refcnt leak in aa_change_profile</title>
<updated>2020-05-27T15:46:41Z</updated>
<author>
<name>Xiyu Yang</name>
<email>xiyuyang19@fudan.edu.cn</email>
</author>
<published>2020-04-05T05:11:55Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=054934aa9faa480276e360588c7286a9490c2a2e'/>
<id>urn:sha1:054934aa9faa480276e360588c7286a9490c2a2e</id>
<content type='text'>
commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream.

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: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang &lt;xiyuyang19@fudan.edu.cn&gt;
Signed-off-by: Xin Tan &lt;tanxin.ctf@gmail.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>apparmor: Fix use-after-free in aa_audit_rule_init</title>
<updated>2020-05-27T15:46:41Z</updated>
<author>
<name>Navid Emamdoost</name>
<email>navid.emamdoost@gmail.com</email>
</author>
<published>2019-10-21T15:23:47Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=97d817b9ef13e2d52a86ea032b0df6a922e0e9df'/>
<id>urn:sha1:97d817b9ef13e2d52a86ea032b0df6a922e0e9df</id>
<content type='text'>
commit c54d481d71c6849e044690d3960aaebc730224cc upstream.

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: 52e8c38001d8 ("apparmor: Fix memory leak of rule on error exit path")
Signed-off-by: Navid Emamdoost &lt;navid.emamdoost@gmail.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock</title>
<updated>2020-01-09T09:20:00Z</updated>
<author>
<name>John Johansen</name>
<email>john.johansen@canonical.com</email>
</author>
<published>2020-01-02T13:31:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e0d2bf5a012974c2f718ce41dbff185666eae11f'/>
<id>urn:sha1:e0d2bf5a012974c2f718ce41dbff185666eae11f</id>
<content type='text'>
commit 8c62ed27a12c00e3db1c9f04bc0f272bdbb06734 upstream.

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: 8e51f9087f40 ("apparmor: Add support for attaching profiles via xattr, presence and value")
Reported-by: Jia-Ju Bai &lt;baijiaju1990@gmail.com&gt;
Reported-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>apparmor: fix unsigned len comparison with less than zero</title>
<updated>2020-01-04T18:18:22Z</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2019-06-27T13:09:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4f13232aa6370e09616563514ed7ef9d81c69f0e'/>
<id>urn:sha1:4f13232aa6370e09616563514ed7ef9d81c69f0e</id>
<content type='text'>
[ Upstream commit 00e0590dbaec6f1bcaa36a85467d7e3497ced522 ]

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: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2019-07-19T17:42:02Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-07-19T17:42:02Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=933a90bf4f3505f8ec83bda21a3c7d70d7c2b426'/>
<id>urn:sha1:933a90bf4f3505f8ec83bda21a3c7d70d7c2b426</id>
<content type='text'>
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()
  ...
</content>
</entry>
</feed>
