When num-threads set not 1, will be crash after running awhile (malloc(): unaligned tcache chunk detected)

[hezhijie0327]

Describe the bug
A clear and concise description of what the bug is.

To reproduce
Steps to reproduce the behavior:

1. set num-threads to 2 or others
2. restart unbound
3. wait for awhile, crash with malloc(): unaligned tcache chunk detected

Expected behavior
A clear and concise description of what you expected to happen.

System:

• Unbound version: Latest commit, self-build
• OS: Ubuntu 22.04
• unbound -V output:

Configure line: --enable-cachedb --enable-dnscrypt --enable-event-api --enable-fully-static --enable-ipsecmod --enable-ipset --enable-linux-ip-local-port-range --enable-pie --enable-relro-now --enable-subnet --enable-tfo-client --enable-tfo-server --with-dynlibmodule --with-libbsd --with-libevent=/tmp/BUILDLIB --with-libexpat=/tmp/BUILDLIB --with-libhiredis=/tmp/BUILDLIB --with-libmnl=/tmp/BUILDLIB --with-libnghttp2=/tmp/BUILDLIB --with-libsodium=/tmp/BUILDLIB --with-pthreads --with-ssl=/tmp/BUILDLIB --without-solaris-threads
Linked libs: libevent 2.1.12-stable (it uses epoll), OpenSSL 3.2.1 30 Jan 2024
Linked modules: dns64 dynlib cachedb ipsecmod subnetcache ipset respip validator iterator
DNSCrypt feature available
TCP Fastopen feature available

BSD licensed, see LICENSE in source package for details.
Report bugs to [email protected] or https://github.com/NLnetLabs/unbound/issues

Additional information
Add any other information that you may have gathered about the issue here.

cachedb:
    backend: 'redis'
    cachedb-no-store: no
    redis-expire-records: yes
    redis-logical-db: 0
    redis-server-host: 127.0.0.1
    redis-server-password: ''
    redis-server-path: ''
    redis-server-port: 6379
    redis-timeout: 1000
remote-control:
    control-interface: 0.0.0.0
    control-interface: ::0
    control-enable: yes
    control-port: 8953
    control-use-cert: no
server:
    access-control: 0.0.0.0/0 allow
    access-control: ::/0 allow
    add-holddown: 2592000
    aggressive-nsec: yes
    answer-cookie: yes
    auto-trust-anchor-file: '/etc/unbound/data/root.key'
    cache-max-negative-ttl: 3600
    cache-max-ttl: 86400
    cache-min-ttl: 0
    caps-whitelist: yes
    chroot: ''
    client-subnet-always-forward: no
    del-holddown: 2592000
    delay-close: 0
    deny-any: yes
    directory: '/etc/unbound'
    disable-dnssec-lame-check: no
    disable-edns-do: no
    do-daemonize: yes
    do-ip4: yes
    do-ip6: yes
    do-nat64: no
    do-not-query-localhost: no
    do-tcp: yes
    do-udp: yes
    ede-serve-expired: yes
    ede: yes
    edns-buffer-size: 1232
    edns-client-string-opcode: 65001
    edns-tcp-keepalive-timeout: 120000
    edns-tcp-keepalive: yes
    extended-statistics: yes
    fast-server-num: 3
    fast-server-permil: 0
    harden-algo-downgrade: yes
    harden-below-nxdomain: yes
    harden-dnssec-stripped: yes
    harden-glue: yes
    harden-large-queries: yes
    harden-referral-path: yes
    harden-short-bufsize: yes
    harden-unknown-additional: yes
    hide-http-user-agent: yes
    hide-identity: yes
    hide-trustanchor: yes
    hide-version: yes
    http-endpoint: '/dns-query'
    http-max-streams: 100
    http-nodelay: yes
    http-notls-downstream: no
    http-query-buffer-size: 4m
    http-response-buffer-size: 4m
    http-user-agent: ''
    https-port: 3353
    identity: ''
    ignore-cd-flag: no
    incoming-num-tcp: 10
    infra-cache-max-rtt: 120000
    infra-cache-min-rtt: 50
    infra-cache-numhosts: 10000
    infra-cache-slabs: 4
    infra-host-ttl: 900
    infra-keep-probing: yes
    insecure-lan-zones: no
    interface: 0.0.0.0@3553
    interface: ::0@3553
    interface-automatic: no
    ip-freebind: yes
    ip-ratelimit: 0
    ip-ratelimit-backoff: yes
    ip-ratelimit-factor: 10
    ip-ratelimit-size: 4m
    ip-ratelimit-slabs: 4
    ip-transparent: yes
    jostle-timeout: 200
    keep-missing: 31622400
    key-cache-size: 64m
    key-cache-slabs: 4
    log-destaddr: no
    log-identity: ''
    log-local-actions: yes
    log-queries: no
    log-replies: no
    log-servfail: no
    log-tag-queryreply: no
    log-time-ascii: yes
    max-client-subnet-ipv4: 24
    max-client-subnet-ipv6: 56
    max-ecs-tree-size-ipv4: 100
    max-ecs-tree-size-ipv6: 100
    max-query-restarts: 11
    max-reuse-tcp-queries: 200
    max-sent-count: 32
    max-udp-size: 1232
    min-client-subnet-ipv4: 0
    min-client-subnet-ipv6: 0
    minimal-responses: yes
    module-config: 'subnetcache validator cachedb iterator'
    msg-buffer-size: 65552
    msg-cache-size: 64m
    msg-cache-slabs: 4
    nat64-prefix: 64:ff9b::/96
    neg-cache-size: 16m
    num-queries-per-thread: 1024
    num-threads: 2
    outbound-msg-retry: 5
    outgoing-num-tcp: 10
    outgoing-range: 4096
    pad-queries-block-size: 128
    pad-queries: yes
    pad-responses-block-size: 468
    pad-responses: yes
    permit-small-holddown: no
    pidfile: '/etc/unbound/work/unbound.pid'
    port: 3553
    prefer-ip4: yes
    prefer-ip6: no
    prefetch-key: yes
    prefetch: yes
    qname-minimisation-strict: no
    qname-minimisation: yes
    ratelimit: 0
    ratelimit-backoff: yes
    ratelimit-factor: 10
    ratelimit-size: 4m
    ratelimit-slabs: 4
    root-hints: '/etc/unbound/data/root.hints'
    root-key-sentinel: yes
    rrset-cache-size: 64m
    rrset-cache-slabs: 4
    rrset-roundrobin: yes
    send-client-subnet: 0.0.0.0/0
    send-client-subnet: ::/0
    serve-expired-client-timeout: 1800
    serve-expired-reply-ttl: 30
    serve-expired-ttl: 259200
    serve-expired-ttl-reset: yes
    serve-expired: yes
    serve-original-ttl: yes
    so-rcvbuf: 0
    so-reuseport: yes
    so-sndbuf: 0
    sock-queue-timeout: 3
    statistics-cumulative: no
    statistics-inhibit-zero: yes
    statistics-interval: 0
    stream-wait-size: 4m
    target-fetch-policy: '3 2 1 0 0'
    tcp-auth-query-timeout: 3000
    tcp-idle-timeout: 30000
    tcp-reuse-timeout: 60000
    tcp-upstream: no
    tls-cert-bundle: '/etc/ssl/certs/ca-certificates.crt'
    tls-port: 3533
    tls-service-key: '/etc/unbound/cert/private.key'
    tls-service-pem: '/etc/unbound/cert/fullchain.cer'
    tls-upstream: no
    tls-use-sni: no
    trust-anchor-signaling: yes
    udp-connect: yes
    udp-upstream-without-downstream: yes
    unblock-lan-zones: no
    unknown-server-time-limit: 376
    unwanted-reply-threshold: 10000000
    use-caps-for-id: no
    use-systemd: no
    username: ''
    use-syslog: no
    val-bogus-ttl: 60
    val-clean-additional: yes
    val-log-level: 0
    val-max-restart: 5
    val-nsec3-keysize-iterations: '1024 150 2048 150 4096 150'
    val-override-date: 0
    val-permissive-mode: yes
    val-sig-skew-max: 86400
    val-sig-skew-min: 3600
    verbosity: 0
    version: ''
    zonemd-permissive-mode: no

[hezhijie0327]

Fixed by building with --without-pthreads