<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/security, branch v4.14.217</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>dump_common_audit_data(): fix racy accesses to -&gt;d_name</title>
<updated>2021-01-23T14:48:43+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2021-01-05T19:43:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2f121a8d64753b3a2d51a97e9c345668feff76f8'/>
<id>2f121a8d64753b3a2d51a97e9c345668feff76f8</id>
<content type='text'>
commit d36a1dd9f77ae1e72da48f4123ed35627848507d upstream.

We are not guaranteed the locking environment that would prevent
dentry getting renamed right under us.  And it's possible for
old long name to be freed after rename, leading to UAF here.

Cc: stable@kernel.org # v2.6.2+
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d36a1dd9f77ae1e72da48f4123ed35627848507d upstream.

We are not guaranteed the locking environment that would prevent
dentry getting renamed right under us.  And it's possible for
old long name to be freed after rename, leading to UAF here.

Cc: stable@kernel.org # v2.6.2+
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Don't modify file descriptor mode on the fly</title>
<updated>2020-12-29T12:47:08+00:00</updated>
<author>
<name>Roberto Sassu</name>
<email>roberto.sassu@huawei.com</email>
</author>
<published>2020-11-26T10:34:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=07c67ec649e049582b3fbb3418bc5f74b361a541'/>
<id>07c67ec649e049582b3fbb3418bc5f74b361a541</id>
<content type='text'>
commit 207cdd565dfc95a0a5185263a567817b7ebf5467 upstream.

Commit a408e4a86b36b ("ima: open a new file instance if no read
permissions") already introduced a second open to measure a file when the
original file descriptor does not allow it. However, it didn't remove the
existing method of changing the mode of the original file descriptor, which
is still necessary if the current process does not have enough privileges
to open a new one.

Changing the mode isn't really an option, as the filesystem might need to
do preliminary steps to make the read possible. Thus, this patch removes
the code and keeps the second open as the only option to measure a file
when it is unreadable with the original file descriptor.

Cc: &lt;stable@vger.kernel.org&gt; # 4.20.x: 0014cc04e8ec0 ima: Set file-&gt;f_mode
Fixes: 2fe5d6def1672 ("ima: integrity appraisal extension")
Signed-off-by: Roberto Sassu &lt;roberto.sassu@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 207cdd565dfc95a0a5185263a567817b7ebf5467 upstream.

Commit a408e4a86b36b ("ima: open a new file instance if no read
permissions") already introduced a second open to measure a file when the
original file descriptor does not allow it. However, it didn't remove the
existing method of changing the mode of the original file descriptor, which
is still necessary if the current process does not have enough privileges
to open a new one.

Changing the mode isn't really an option, as the filesystem might need to
do preliminary steps to make the read possible. Thus, this patch removes
the code and keeps the second open as the only option to measure a file
when it is unreadable with the original file descriptor.

Cc: &lt;stable@vger.kernel.org&gt; # 4.20.x: 0014cc04e8ec0 ima: Set file-&gt;f_mode
Fixes: 2fe5d6def1672 ("ima: integrity appraisal extension")
Signed-off-by: Roberto Sassu &lt;roberto.sassu@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling</title>
<updated>2020-12-29T12:46:52+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul@paul-moore.com</email>
</author>
<published>2020-11-03T16:49:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=44f5d9fecd8038d79342e0d03e9acbd120c4621f'/>
<id>44f5d9fecd8038d79342e0d03e9acbd120c4621f</id>
<content type='text'>
[ Upstream commit 200ea5a2292dc444a818b096ae6a32ba3caa51b9 ]

A previous fix, commit 83370b31a915 ("selinux: fix error initialization
in inode_doinit_with_dentry()"), changed how failures were handled
before a SELinux policy was loaded.  Unfortunately that patch was
potentially problematic for two reasons: it set the isec-&gt;initialized
state without holding a lock, and it didn't set the inode's SELinux
label to the "default" for the particular filesystem.  The later can
be a problem if/when a later attempt to revalidate the inode fails
and SELinux reverts to the existing inode label.

This patch should restore the default inode labeling that existed
before the original fix, without affecting the LABEL_INVALID marking
such that revalidation will still be attempted in the future.

Fixes: 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()")
Reported-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Tested-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Reviewed-by: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 200ea5a2292dc444a818b096ae6a32ba3caa51b9 ]

A previous fix, commit 83370b31a915 ("selinux: fix error initialization
in inode_doinit_with_dentry()"), changed how failures were handled
before a SELinux policy was loaded.  Unfortunately that patch was
potentially problematic for two reasons: it set the isec-&gt;initialized
state without holding a lock, and it didn't set the inode's SELinux
label to the "default" for the particular filesystem.  The later can
be a problem if/when a later attempt to revalidate the inode fails
and SELinux reverts to the existing inode label.

This patch should restore the default inode labeling that existed
before the original fix, without affecting the LABEL_INVALID marking
such that revalidation will still be attempted in the future.

Fixes: 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()")
Reported-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Tested-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Reviewed-by: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: fix error initialization in inode_doinit_with_dentry()</title>
<updated>2020-12-29T12:46:51+00:00</updated>
<author>
<name>Tianyue Ren</name>
<email>rentianyue@kylinos.cn</email>
</author>
<published>2020-10-09T01:36:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ce7acf72db8c4dbf7e9e9aa942ab26342a60ab7c'/>
<id>ce7acf72db8c4dbf7e9e9aa942ab26342a60ab7c</id>
<content type='text'>
[ Upstream commit 83370b31a915493231e5b9addc72e4bef69f8d31 ]

Mark the inode security label as invalid if we cannot find
a dentry so that we will retry later rather than marking it
initialized with the unlabeled SID.

Fixes: 9287aed2ad1f ("selinux: Convert isec-&gt;lock into a spinlock")
Signed-off-by: Tianyue Ren &lt;rentianyue@kylinos.cn&gt;
[PM: minor comment tweaks]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 83370b31a915493231e5b9addc72e4bef69f8d31 ]

Mark the inode security label as invalid if we cannot find
a dentry so that we will retry later rather than marking it
initialized with the unlabeled SID.

Fixes: 9287aed2ad1f ("selinux: Convert isec-&gt;lock into a spinlock")
Signed-off-by: Tianyue Ren &lt;rentianyue@kylinos.cn&gt;
[PM: minor comment tweaks]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: Fix error return code in sel_ib_pkey_sid_slow()</title>
<updated>2020-11-18T17:27:58+00:00</updated>
<author>
<name>Chen Zhou</name>
<email>chenzhou10@huawei.com</email>
</author>
<published>2020-11-12T13:53:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=531ef54548372c6b5b3eb5e5f264119b01a85ddb'/>
<id>531ef54548372c6b5b3eb5e5f264119b01a85ddb</id>
<content type='text'>
commit c350f8bea271782e2733419bd2ab9bf4ec2051ef upstream.

Fix to return a negative error code from the error handling case
instead of 0 in function sel_ib_pkey_sid_slow(), as done elsewhere
in this function.

Cc: stable@vger.kernel.org
Fixes: 409dcf31538a ("selinux: Add a cache for quicker retreival of PKey SIDs")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Signed-off-by: Chen Zhou &lt;chenzhou10@huawei.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c350f8bea271782e2733419bd2ab9bf4ec2051ef upstream.

Fix to return a negative error code from the error handling case
instead of 0 in function sel_ib_pkey_sid_slow(), as done elsewhere
in this function.

Cc: stable@vger.kernel.org
Fixes: 409dcf31538a ("selinux: Add a cache for quicker retreival of PKey SIDs")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Signed-off-by: Chen Zhou &lt;chenzhou10@huawei.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Don't ignore errors from crypto_shash_update()</title>
<updated>2020-10-29T08:07:00+00:00</updated>
<author>
<name>Roberto Sassu</name>
<email>roberto.sassu@huawei.com</email>
</author>
<published>2020-09-04T09:23:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d0f7036b12840c55882f680df584d855f599f017'/>
<id>d0f7036b12840c55882f680df584d855f599f017</id>
<content type='text'>
commit 60386b854008adc951c470067f90a2d85b5d520f upstream.

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 &lt;roberto.sassu@huawei.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 60386b854008adc951c470067f90a2d85b5d520f upstream.

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 &lt;roberto.sassu@huawei.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: sel_avc_get_stat_idx should increase position index</title>
<updated>2020-10-01T11:12:33+00:00</updated>
<author>
<name>Vasily Averin</name>
<email>vvs@virtuozzo.com</email>
</author>
<published>2020-02-01T07:47:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=dd79c17744311f20facf056c0d56a88a48c1c464'/>
<id>dd79c17744311f20facf056c0d56a88a48c1c464</id>
<content type='text'>
[ Upstream commit 8d269a8e2a8f0bca89022f4ec98de460acb90365 ]

If seq_file .next function does not change position index,
read after some lseek can generate unexpected output.

$ dd if=/sys/fs/selinux/avc/cache_stats # usual output
lookups hits misses allocations reclaims frees
817223 810034 7189 7189 6992 7037
1934894 1926896 7998 7998 7632 7683
1322812 1317176 5636 5636 5456 5507
1560571 1551548 9023 9023 9056 9115
0+1 records in
0+1 records out
189 bytes copied, 5,1564e-05 s, 3,7 MB/s

$# read after lseek to midle of last line
$ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
056 9115   &lt;&lt;&lt;&lt; end of last line
1560571 1551548 9023 9023 9056 9115  &lt;&lt;&lt; whole last line once again
0+1 records in
0+1 records out
45 bytes copied, 8,7221e-05 s, 516 kB/s

$# read after lseek beyond  end of of file
$ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
1560571 1551548 9023 9023 9056 9115  &lt;&lt;&lt;&lt; generates whole last line
0+1 records in
0+1 records out
36 bytes copied, 9,0934e-05 s, 396 kB/s

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Signed-off-by: Vasily Averin &lt;vvs@virtuozzo.com&gt;
Acked-by: Stephen Smalley &lt;sds@tycho.nsa.gov&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8d269a8e2a8f0bca89022f4ec98de460acb90365 ]

If seq_file .next function does not change position index,
read after some lseek can generate unexpected output.

$ dd if=/sys/fs/selinux/avc/cache_stats # usual output
lookups hits misses allocations reclaims frees
817223 810034 7189 7189 6992 7037
1934894 1926896 7998 7998 7632 7683
1322812 1317176 5636 5636 5456 5507
1560571 1551548 9023 9023 9056 9115
0+1 records in
0+1 records out
189 bytes copied, 5,1564e-05 s, 3,7 MB/s

$# read after lseek to midle of last line
$ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
056 9115   &lt;&lt;&lt;&lt; end of last line
1560571 1551548 9023 9023 9056 9115  &lt;&lt;&lt; whole last line once again
0+1 records in
0+1 records out
45 bytes copied, 8,7221e-05 s, 516 kB/s

$# read after lseek beyond  end of of file
$ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
1560571 1551548 9023 9023 9056 9115  &lt;&lt;&lt;&lt; generates whole last line
0+1 records in
0+1 records out
36 bytes copied, 9,0934e-05 s, 396 kB/s

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Signed-off-by: Vasily Averin &lt;vvs@virtuozzo.com&gt;
Acked-by: Stephen Smalley &lt;sds@tycho.nsa.gov&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Smack: prevent underflow in smk_set_cipso()</title>
<updated>2020-08-21T07:48:11+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2020-07-23T15:23:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=75f8b5a67b62b40d6308f3f2998de2cfa264f212'/>
<id>75f8b5a67b62b40d6308f3f2998de2cfa264f212</id>
<content type='text'>
[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ]

We have an upper bound on "maplevel" but forgot to check for negative
values.

Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ]

We have an upper bound on "maplevel" but forgot to check for negative
values.

Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Smack: fix another vsscanf out of bounds</title>
<updated>2020-08-21T07:48:11+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2020-07-23T15:22:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=12917b448aa665cfa032f37925a10ae5f43bee35'/>
<id>12917b448aa665cfa032f37925a10ae5f43bee35</id>
<content type='text'>
[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]

This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".

Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]

This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".

Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Smack: fix use-after-free in smk_write_relabel_self()</title>
<updated>2020-08-21T07:48:02+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2020-07-08T20:15:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a963ddc8fffada154a87ca407fdfc850618ba49b'/>
<id>a963ddc8fffada154a87ca407fdfc850618ba49b</id>
<content type='text'>
commit beb4ee6770a89646659e6a2178538d2b13e2654e upstream.

smk_write_relabel_self() frees memory from the task's credentials with
no locking, which can easily cause a use-after-free because multiple
tasks can share the same credentials structure.

Fix this by using prepare_creds() and commit_creds() to correctly modify
the task's credentials.

Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self":

	#include &lt;fcntl.h&gt;
	#include &lt;pthread.h&gt;
	#include &lt;unistd.h&gt;

	static void *thrproc(void *arg)
	{
		int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY);
		for (;;) write(fd, "foo", 3);
	}

	int main()
	{
		pthread_t t;
		pthread_create(&amp;t, NULL, thrproc, NULL);
		thrproc(NULL);
	}

Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com
Fixes: 38416e53936e ("Smack: limited capability for changing process label")
Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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commit beb4ee6770a89646659e6a2178538d2b13e2654e upstream.

smk_write_relabel_self() frees memory from the task's credentials with
no locking, which can easily cause a use-after-free because multiple
tasks can share the same credentials structure.

Fix this by using prepare_creds() and commit_creds() to correctly modify
the task's credentials.

Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self":

	#include &lt;fcntl.h&gt;
	#include &lt;pthread.h&gt;
	#include &lt;unistd.h&gt;

	static void *thrproc(void *arg)
	{
		int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY);
		for (;;) write(fd, "foo", 3);
	}

	int main()
	{
		pthread_t t;
		pthread_create(&amp;t, NULL, thrproc, NULL);
		thrproc(NULL);
	}

Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com
Fixes: 38416e53936e ("Smack: limited capability for changing process label")
Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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