<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 06:24:56 UTC 2024

It is possible to restrict the fields that are returned in this document by specifying the 'field' parameter in your request.
For example, to request only the issue key and summary append 'field=key&field=summary' to the URL of your request.
-->
<rss version="0.92" >
<channel>
    <title>MongoDB Jira</title>
    <link>https://jira.mongodb.org</link>
    <description>This file is an XML representation of an issue</description>
    <language>en-us</language>    <build-info>
        <version>9.7.1</version>
        <build-number>970001</build-number>
        <build-date>13-04-2023</build-date>
    </build-info>


<item>
            <title>[SERVER-73534] Serialization of &apos;sbe::TypeTags::ArraySet&apos; to &apos;KeyString&apos; can segfault</title>
                <link>https://jira.mongodb.org/browse/SERVER-73534</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;This code is incorrect:&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;https://github.com/mongodb/mongo/blob/e536ab12f0be25b42983aaf492fa5eefc4cf8ce0/src/mongo/db/exec/sbe/values/slot.cpp#L456-L465&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/blob/e536ab12f0be25b42983aaf492fa5eefc4cf8ce0/src/mongo/db/exec/sbe/values/slot.cpp#L456-L465&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;In the case that the input &lt;tt&gt;tag&lt;/tt&gt; indicates that the value is type &lt;tt&gt;Array&lt;/tt&gt;, everything works as expected. When the value is an &lt;tt&gt;ArraySet&lt;/tt&gt;, however, this code leads to undefined behavior. I&apos;ve seen it consistently crash the server with a segfault in practice.&lt;/p&gt;

&lt;p&gt;The problem is that it calls &lt;tt&gt;getArrayView()&lt;/tt&gt; on a value of type &lt;tt&gt;Array&lt;/tt&gt;. This ends up interpreting the value as a pointer to an &lt;tt&gt;Array&lt;/tt&gt; object when the value&apos;s actual runtime type is &lt;tt&gt;ArraySet&lt;/tt&gt;. As soon as we try to access a data member of the pointed-to object, which &lt;a href=&quot;https://github.com/mongodb/mongo/blob/e536ab12f0be25b42983aaf492fa5eefc4cf8ce0/src/mongo/db/exec/sbe/values/value.cpp#L861&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;happens here&lt;/a&gt;, we crash.&lt;/p&gt;

&lt;p&gt;The buggy function is used for spilling to disk in SBE&apos;s &lt;tt&gt;HashAggStage&lt;/tt&gt; and &lt;tt&gt;HashLookupStage&lt;/tt&gt;. Therefore, the crash can happen if we ever decide to spill an entry in the hash table whose key contains a value of type &lt;tt&gt;ArraySet&lt;/tt&gt;. This is a somewhat unusual situation, since it requires the following:&lt;/p&gt;
&lt;ol&gt;
	&lt;li&gt;A &lt;tt&gt;$group&lt;/tt&gt; or &lt;tt&gt;$lookup&lt;/tt&gt; that needs to spill at runtime.&lt;/li&gt;
	&lt;li&gt;The &lt;tt&gt;$group&lt;/tt&gt; or &lt;tt&gt;$lookup&lt;/tt&gt; must be pushed down to SBE.&lt;/li&gt;
	&lt;li&gt;The query must be such that an &lt;tt&gt;ArraySet&lt;/tt&gt; becomes a key in the hash table. This is presumably an unusual use of MQL&apos;s set arithmetic operators.&lt;/li&gt;
&lt;/ol&gt;


&lt;p&gt;This is a latent issue that was discovered our generational agg fuzzer. It was exposed due to the changes from &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-70395&quot; title=&quot;Slot-Based Engine too aggressively uses disk for $group and is slow&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-70395&quot;&gt;&lt;del&gt;SERVER-70395&lt;/del&gt;&lt;/a&gt;, but I believe that it affects all 6.0.x and 6.2.x versions. The reason we found it is that &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-70395&quot; title=&quot;Slot-Based Engine too aggressively uses disk for $group and is slow&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-70395&quot;&gt;&lt;del&gt;SERVER-70395&lt;/del&gt;&lt;/a&gt; made a change to artificially increase the likelihood of spilling in debug builds. For this reason, as soon as &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-70395&quot; title=&quot;Slot-Based Engine too aggressively uses disk for $group and is slow&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-70395&quot;&gt;&lt;del&gt;SERVER-70395&lt;/del&gt;&lt;/a&gt; was merged we started seeing the fuzzer cause this crash on debug builds only.&lt;/p&gt;</description>
                <environment></environment>
        <key id="2250193">SERVER-73534</key>
            <summary>Serialization of &apos;sbe::TypeTags::ArraySet&apos; to &apos;KeyString&apos; can segfault</summary>
                <type id="1" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14703&amp;avatarType=issuetype">Bug</type>
                                            <priority id="3" iconUrl="https://jira.mongodb.org/images/icons/priorities/major.svg">Major - P3</priority>
                        <status id="6" iconUrl="https://jira.mongodb.org/images/icons/statuses/closed.png" description="The issue is considered finished, the resolution is correct. Issues which are closed can be reopened.">Closed</status>
                    <statusCategory id="3" key="done" colorName="success"/>
                                    <resolution id="13201">Fixed</resolution>
                                        <assignee username="david.storch@mongodb.com">David Storch</assignee>
                                    <reporter username="david.storch@mongodb.com">David Storch</reporter>
                        <labels>
                    </labels>
                <created>Wed, 1 Feb 2023 23:14:35 +0000</created>
                <updated>Sun, 29 Oct 2023 21:27:02 +0000</updated>
                            <resolved>Fri, 3 Feb 2023 17:19:45 +0000</resolved>
                                                    <fixVersion>6.3.0-rc0</fixVersion>
                    <fixVersion>6.0.5</fixVersion>
                                    <component>Query Execution</component>
                                        <votes>0</votes>
                                    <watches>8</watches>
                                                                                                                <comments>
                            <comment id="5172207" author="xgen-internal-githook" created="Mon, 6 Feb 2023 21:34:01 +0000"  >&lt;p&gt;Author: &lt;/p&gt;
{&apos;name&apos;: &apos;David Storch&apos;, &apos;email&apos;: &apos;david.storch@mongodb.com&apos;, &apos;username&apos;: &apos;dstorch&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-73534&quot; title=&quot;Serialization of &amp;#39;sbe::TypeTags::ArraySet&amp;#39; to &amp;#39;KeyString&amp;#39; can segfault&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-73534&quot;&gt;&lt;del&gt;SERVER-73534&lt;/del&gt;&lt;/a&gt; Fix crash in serialization of SBE ArraySet to KeyString&lt;/p&gt;

&lt;p&gt;(cherry picked from commit 7d633d3c72a5cffb8889632e5cfb545002514ebb)&lt;br/&gt;
Branch: v6.0&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/a002b8db7c521b553a9c5a4ad806af83754c7b55&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/a002b8db7c521b553a9c5a4ad806af83754c7b55&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="5166352" author="xgen-internal-githook" created="Fri, 3 Feb 2023 17:15:21 +0000"  >&lt;p&gt;Author: &lt;/p&gt;
{&apos;name&apos;: &apos;David Storch&apos;, &apos;email&apos;: &apos;david.storch@mongodb.com&apos;, &apos;username&apos;: &apos;dstorch&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-73534&quot; title=&quot;Serialization of &amp;#39;sbe::TypeTags::ArraySet&amp;#39; to &amp;#39;KeyString&amp;#39; can segfault&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-73534&quot;&gt;&lt;del&gt;SERVER-73534&lt;/del&gt;&lt;/a&gt; Fix crash in serialization of SBE ArraySet to KeyString&lt;br/&gt;
Branch: master&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/7d633d3c72a5cffb8889632e5cfb545002514ebb&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/7d633d3c72a5cffb8889632e5cfb545002514ebb&lt;/a&gt;&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10420">
                    <name>Backports</name>
                                            <outwardlinks description="backported by">
                                                        </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10011">
                    <name>Depends</name>
                                                                <inwardlinks description="is depended on by">
                                                        </inwardlinks>
                                    </issuelinktype>
                            <issuelinktype id="10012">
                    <name>Related</name>
                                            <outwardlinks description="related to">
                                        <issuelink>
            <issuekey id="1929363">SERVER-61629</issuekey>
        </issuelink>
                            </outwardlinks>
                                                        </issuelinktype>
                    </issuelinks>
                <attachments>
                    </attachments>
                <subtasks>
                    </subtasks>
                <customfields>
                                                <customfield id="customfield_10050" key="com.atlassian.jira.toolkit:comments">
                        <customfieldname># Replies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18555" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname># of Sprints</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_12450" key="com.atlassian.jira.plugin.system.customfieldtypes:multicheckboxes">
                        <customfieldname>Backport Requested</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="23470"><![CDATA[v6.0]]></customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10011" key="com.atlassian.jira.plugin.system.customfieldtypes:radiobuttons">
                        <customfieldname>Backwards Compatibility</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="10038"><![CDATA[Fully Compatible]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                            <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Thu, 2 Feb 2023 16:23:15 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        1 year, 2 days ago
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18254" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Dependencies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue><![CDATA[]]></customfieldvalue>


                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_15850" key="com.atlassian.jira.plugins.jira-development-integration-plugin:devsummary">
                        <customfieldname>Development</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                        <customfield id="customfield_17050" key="com.atlassian.jira.plugin.system.customfieldtypes:radiobuttons">
                        <customfieldname>Downstream Team Attention</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="16941"><![CDATA[Not Needed]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_10057" key="com.atlassian.jira.toolkit:lastusercommented">
                        <customfieldname>Last comment by Customer</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>true</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                            <customfield id="customfield_10056" key="com.atlassian.jira.toolkit:lastupdaterorcommenter">
                        <customfieldname>Last commenter</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>luke.bonanomi@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            1 year, 2 days ago
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_16465" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Linked BF Score</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>164.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                        <customfield id="customfield_10032" key="com.atlassian.jira.plugin.system.customfieldtypes:select">
                        <customfieldname>Operating System</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="10026"><![CDATA[ALL]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>david.storch@mongodb.com</customfieldvalue>
            <customfieldvalue>xgen-internal-githook</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|i1tj5j:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hr2lp3:wr</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10558" key="com.pyxis.greenhopper.jira:gh-global-rank">
                        <customfieldname>Rank (Obsolete)</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>9223372036854775807</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                            <customfield id="customfield_23361" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Requested By</customfieldname>
                        <customfieldvalues>
                                

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                            <customfield id="customfield_22250" key="com.atlassian.jira.plugin.system.customfieldtypes:radiobuttons">
                        <customfieldname>Special Downgrade Instructions Required</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="23343"><![CDATA[Not Needed]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10557" key="com.pyxis.greenhopper.jira:gh-sprint">
                        <customfieldname>Sprint</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue id="5930">QE 2023-02-06</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_10053" key="com.atlassian.jira.ext.charting:timeinstatus">
                        <customfieldname>Time In Status</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_22870" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Triagers</customfieldname>
                        <customfieldvalues>
                                

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                    <customfield id="customfield_14350" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>serverRank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|i1t5av:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                    </customfields>
    </item>
</channel>
</rss>