#!/usr/bin/env bash
# -*- coding: utf-8 -*-
#
# dissector_fuzz.sh -- fuzz test netsniff-ng's dissector and pcap io methods
#		       with shitty pcap example files from the Wireshark archive
#
# Copyright (C) 2012 Daniel Borkmann <borkmann@redhat.com>
# Copyright (C) 2012 Stefan Seering <sseerin@imn.htwk-leipzig.de>
#
# Note: build and *install* the toolkit first before running this script!
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.

set -u

if [ ${BASH_VERSINFO} -lt 3 ] ; then
	echo 'Error: Your bash need to be version 3 or newer. Exiting.'
	exit 1 # operators like =~ produce errors silently in old bash versions, so exit here
fi

archive='ftp://wireshark.org/automated/captures/'
show_output='' # empty string evaluates to false
run_through='' # empty string evaluates to false
count_cores=0
count_files=0
netsniff_ng_opts=''

if [ $# -gt 0 ] ; then
	if [ "$1" = '-h' -o "$1" = '--help' -o "$1" = '--usage' ] ; then
		echo 'Usage: dissector_fuzz [-s (show netsniff-ng output, default: no)] [-r (keep running on errors, default: no)] [netsniff-ng long-args]'
		exit 0
	fi

	for opt in $@ ; do
		if [ "${opt}" = '-s' ] ; then
			show_output='true'
		elif [ "${opt}" = '-r' ] ; then
			run_through='true'
		else
			netsniff_ng_opts="${netsniff_ng_opts} ${opt}";
		fi
	done
fi

mkdir -p fuzzing
cd fuzzing
wget -r -Nc -np -nd -A.pcap "$archive"  |& grep -E "%|^--"
ulimit -c unlimited
rm -f core
for file in *.pcap
do
	echo "Testing file $file ..."
	if [ $show_output ]; then
		netsniff-ng --in "$file" "${netsniff_ng_opts}"
	else
		netsniff-ng --in "$file" "${netsniff_ng_opts}" > /dev/null
	fi
	if [ -e core ]; then
		echo "Fuck, core dumped on $file!"
		let count_cores=count_cores+1
		if [ $run_through ]; then
			rm core
		else
			exit
		fi
	fi
done

if which cowsay > /dev/null ; then
	echo_cmd='cowsay'
else
	echo_cmd='echo'
fi

${echo_cmd} 'Your fuckup Score'
echo " * tested pcaps: $count_files"
echo " * core dumps:   $count_cores"
cgit.cgi/linux/net-next.git/diff/net/nfc/nci/lib.c?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/net/nfc/nci/lib.c'>
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<option value='grep'>log msg</option>
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</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/net?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>net</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/nfc?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>nfc</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/nfc/nci?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>nci</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/nfc/nci/lib.c?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351'>lib.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/net/nfc/nci/lib.c?h=nds-private-remove&amp;id=b2347a322d1f6f93f1a39fe17ed08628fc959351&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select 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/include/crypto/drbg.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/crypto/drbg.h?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/include/crypto/drbg.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>include/crypto/drbg.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/crypto/drbg.h?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/crypto/drbg.h?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 'include/crypto/drbg.h')</div><table summary='diffstat' class='diffstat'>