/*
 * NetLabel NETLINK Interface
 *
 * This file defines the NETLINK interface for the NetLabel system.  The
 * NetLabel system manages static and dynamic label mappings for network
 * protocols such as CIPSO and RIPSO.
 *
 * Author: Paul Moore <paul@paul-moore.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/socket.h>
#include <linux/audit.h>
#include <linux/tty.h>
#include <linux/security.h>
#include <linux/gfp.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <asm/bug.h>

#include "netlabel_mgmt.h"
#include "netlabel_unlabeled.h"
#include "netlabel_cipso_v4.h"
#include "netlabel_calipso.h"
#include "netlabel_user.h"

/*
 * NetLabel NETLINK Setup Functions
 */

/**
 * netlbl_netlink_init - Initialize the NETLINK communication channel
 *
 * Description:
 * Call out to the NetLabel components so they can register their families and
 * commands with the Generic NETLINK mechanism.  Returns zero on success and
 * non-zero on failure.
 *
 */
int __init netlbl_netlink_init(void)
{
	int ret_val;

	ret_val = netlbl_mgmt_genl_init();
	if (ret_val != 0)
		return ret_val;

	ret_val = netlbl_cipsov4_genl_init();
	if (ret_val != 0)
		return ret_val;

	ret_val = netlbl_calipso_genl_init();
	if (ret_val != 0)
		return ret_val;

	return netlbl_unlabel_genl_init();
}

/*
 * NetLabel Audit Functions
 */

/**
 * netlbl_audit_start_common - Start an audit message
 * @type: audit message type
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Start an audit message using the type specified in @type and fill the audit
 * message with some fields common to all NetLabel audit messages.  Returns
 * a pointer to the audit buffer on success, NULL on failure.
 *
 */
struct audit_buffer *netlbl_audit_start_common(int type,
					       struct netlbl_audit *audit_info)
{
	struct audit_buffer *audit_buf;
	char *secctx;
	u32 secctx_len;

	if (audit_enabled == 0)
		return NULL;

	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC, type);
	if (audit_buf == NULL)
		return NULL;

	audit_log_format(audit_buf, "netlabel: auid=%u ses=%u",
			 from_kuid(&init_user_ns, audit_info->loginuid),
			 audit_info->sessionid);

	if (audit_info->secid != 0 &&
	    security_secid_to_secctx(audit_info->secid,
				     &secctx,
				     &secctx_len) == 0) {
		audit_log_format(audit_buf, " subj=%s", secctx);
		security_release_secctx(secctx, secctx_len);
	}

	return audit_buf;
}
ove&amp;id=70ad35067c99dd6fb1fefbabf11dd53806f1978c'>testing</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools/testing/radix-tree?h=nds-private-remove&amp;id=70ad35067c99dd6fb1fefbabf11dd53806f1978c'>radix-tree</a>/<a href='/cgit.cgi/linux/net-next.git/log/tools/testing/radix-tree/test.c?h=nds-private-remove&amp;id=70ad35067c99dd6fb1fefbabf11dd53806f1978c'>test.c</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/tools/testing/radix-tree/test.c?h=nds-private-remove&amp;id=70ad35067c99dd6fb1fefbabf11dd53806f1978c&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
ct name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ieee802154/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ieee802154/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ieee802154/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>net/ieee802154/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ieee802154/Kconfig?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ieee802154/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().

This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:

__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0

Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.

The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.

Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'net/ieee802154/Kconfig')</div><table summary='diffstat' class='diffstat'>