[Bug]: Error PHP unserialize

[punkyard]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hi
I would like to report a repeated error I can find in NC logs. I'm afraid I can't evaluate its consequences, many errors arrived at the same time: locked files, antivirus, SQL and redis server.

Steps to reproduce

find logs in NC Logging:

[PHP] Error: unserialize(): Error at offset 40 of 43 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#574
	PROPFIND /remote.php/dav/addressbooks/users/UserName/
	from 185.252.235.96 by UserName at 8 sept. 2024, 19:22:05

Expected behavior

no error

Nextcloud Server version

29

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Nginx

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

Updated from a MINOR version (ex. 28.0.1 to 28.0.2)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

{"reqId":"YizWhMVEux6WGmu7Clxp","level":3,"time":"2024-09-08T17:22:05+00:00","remoteAddr":"185.252.235.96","user":"UserName","app":"PHP","method":"PROPFIND","url":"/remote.php/dav/addressbooks/users/UserName/","message":"unserialize(): Error at offset 40 of 43 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#574","userAgent":"Mac OS X/10.15.7 (19H2026) AddressBookCore/1","version":"29.0.4.1","data":{"app":"PHP"},"id":"66e090d696463"}

### Additional info


#Server configuration detail
Operating system: Linux 5.10.0-32-amd64 [#](https://notre.rez0.net/s/ztLijxYSegjCmjt#h-server-configuration-detail)1 SMP Debian 5.10.223-1 (2024-08-10) x86_64

Webserver: Apache/2.4.62 (Unix) (fpm-fcgi)

Database: pgsql PostgreSQL 16.3 on x86_64-pc-linux-musl, compiled by gcc (Alpine 13.2.1_git20240309) 13.2.1 20240309, 64-bit

PHP version: 8.2.21

Modules loaded: Core, date, libxml, openssl, pcre, sqlite3, zlib, ctype, curl, dom, fileinfo, filter, hash, iconv, json, mbstring, SPL, session, PDO, pdo_sqlite, bz2, posix, random, readline, Reflection, standard, SimpleXML, tokenizer, xml, xmlreader, xmlwriter, mysqlnd, cgi-fcgi, apcu, bcmath, Phar, exif, ftp, gd, gmp, igbinary, imagick, imap, intl, ldap, memcached, pcntl, pdo_pgsql, pgsql, redis, smbclient, sodium, sysvsem, zip, libsmbclient, Zend OPcache

Nextcloud version: 29.0.4 - 29.0.4.1

Updated from an older Nextcloud/ownCloud or fresh install:

Where did you install Nextcloud from: unknown

<details><summary>Signing status</summary>

[]
</details>

<details><summary>List of activated apps</summary>


Enabled:
 - activity: 2.21.1
 - admin_audit: 1.19.0
 - announcementcenter: 6.8.1
 - auto_groups: 1.5.3
 - bruteforcesettings: 2.9.0
 - calendar: 4.7.16
 - cfg_share_links: 5.1.3
 - circles: 29.0.0-dev
 - cloud_federation_api: 1.12.0
 - collectives: 2.14.3
 - comments: 1.19.0
 - contacts: 6.0.0
 - contactsinteraction: 1.10.0
 - dashboard: 7.9.0
 - dav: 1.30.1
 - deck: 1.13.1
 - event_update_notification: 2.4.0
 - external: 5.4.0
 - federatedfilesharing: 1.19.0
 - files: 2.1.0
 - files_antivirus: 5.5.7
 - files_downloadlimit: 2.0.0
 - files_pdfviewer: 2.10.0
 - files_reminders: 1.2.0
 - files_sharing: 1.21.0
 - files_trashbin: 1.19.0
 - files_versions: 1.22.0
 - forms: 4.2.4
 - group_default_quota: 0.1.10
 - groupfolders: 17.0.3
 - integration_excalidraw: 2.2.0
 - integration_youtube: 0.3.0
 - logreader: 2.14.0
 - lookup_server_connector: 1.17.0
 - mail: 3.7.8
 - money: 0.28.0
 - nextcloud-aio: 0.6.0
 - nextcloud_announcements: 1.18.0
 - notes: 4.10.1
 - notifications: 2.17.0
 - notify_push: 0.7.0
 - oauth2: 1.17.0
 - password_policy: 1.19.0
 - polls: 7.2.2
 - provisioning_api: 1.19.0
 - quota_warning: 1.20.0
 - registration: 2.4.0
 - related_resources: 1.4.0
 - richdocuments: 8.4.6
 - settings: 1.12.0
 - sharebymail: 1.19.0
 - side_menu: 3.13.1
 - spreed: 19.0.8
 - support: 1.12.0
 - suspicious_login: 7.0.0
 - tasks: 0.16.1
 - terms_of_service: 2.5.0
 - text: 3.10.1
 - theming: 2.4.0
 - timemanager: 0.3.15
 - twofactor_backupcodes: 1.18.0
 - unroundedcorners: 1.1.3
 - user_status: 1.9.0
 - viewer: 2.3.0
 - welcome: 1.2.0
 - workflowengine: 2.11.0
Disabled:
 - encryption
 - federation: 1.17.0
 - files_external
 - firstrunwizard: 2.14.0
 - impersonate: 1.16.0
 - photos: 2.3.0
 - privacy: 1.13.0
 - recommendations: 1.4.0
 - serverinfo: 1.16.0
 - survey_client: 1.13.0
 - systemtags: 1.18.0
 - twofactor_totp: 7.0.0
 - user_ldap
 - weather_status: 1.5.0

</details>

<details><summary>Configuration (config/config.php)</summary>


{
    "memcache.local": "\\OC\\Memcache\\APCu",
    "apps_paths": [
        {
            "path": "\/var\/www\/html\/apps",
            "url": "\/apps",
            "writable": false
        },
        {
            "path": "\/var\/www\/html\/custom_apps",
            "url": "\/custom_apps",
            "writable": true
        }
    ],
    "memcache.distributed": "\\OC\\Memcache\\Redis",
    "memcache.locking": "\\OC\\Memcache\\Redis",
    "redis": {
        "host": "***REMOVED SENSITIVE VALUE***",
        "password": "***REMOVED SENSITIVE VALUE***",
        "port": 6379
    },
    "overwriteprotocol": "https",
    "passwordsalt": "***REMOVED SENSITIVE VALUE***",
    "secret": "***REMOVED SENSITIVE VALUE***",
    "trusted_domains": [
        "localhost",
        "notre.rez0.net",
        "kolab.koraland.net"
    ],
    "datadirectory": "***REMOVED SENSITIVE VALUE***",
    "skeletondirectory": "\/var\/lib\/docker\/volumes\/nextcloud_aio_nextcloud\/_data\/skeleton",
    "dbtype": "pgsql",
    "version": "29.0.4.1",
    "dbname": "***REMOVED SENSITIVE VALUE***",
    "dbhost": "***REMOVED SENSITIVE VALUE***",
    "dbport": "",
    "dbtableprefix": "oc_",
    "dbuser": "***REMOVED SENSITIVE VALUE***",
    "dbpassword": "***REMOVED SENSITIVE VALUE***",
    "installed": true,
    "instanceid": "***REMOVED SENSITIVE VALUE***",
    "check_data_directory_permissions": true,
    "maintenance": false,
    "loglevel": 2,
    "log_type": "file",
    "logfile": "\/var\/www\/html\/data\/nextcloud.log",
    "log_rotate_size": "10485760",
    "log.condition": {
        "apps": [
            "admin_audit"
        ]
    },
    "preview_max_x": "2048",
    "preview_max_y": "2048",
    "jpeg_quality": "60",
    "enabledPreviewProviders": {
        "1": "OC\\Preview\\Image",
        "2": "OC\\Preview\\MarkDown",
        "3": "OC\\Preview\\MP3",
        "4": "OC\\Preview\\TXT",
        "5": "OC\\Preview\\OpenDocument",
        "6": "OC\\Preview\\Movie",
        "0": "OC\\Preview\\Imaginary"
    },
    "enable_previews": true,
    "upgrade.disable-web": true,
    "trashbin_retention_obligation": "auto, 30",
    "versions_retention_obligation": "auto, 30",
    "activity_expire_days": "30",
    "simpleSignUpLink.shown": false,
    "share_folder": "\/Shared",
    "one-click-instance": true,
    "one-click-instance.user-limit": 100,
    "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
    "htaccess.RewriteBase": "\/",
    "files_external_allow_create_new_local": true,
    "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
    "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
    "default_language": "fr",
    "default_locale": "fr_FR",
    "default_phone_region": "FR",
    "mail_sendmailmode": "smtp",
    "mail_from_address": "***REMOVED SENSITIVE VALUE***",
    "mail_domain": "***REMOVED SENSITIVE VALUE***",
    "mail_smtpauthtype": "LOGIN",
    "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
    "mail_smtpport": "465",
    "mail_smtpauth": 1,
    "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
    "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
    "allow_local_remote_servers": true,
    "updatedirectory": "\/nc-updater",
    "overwritehost": "notre.rez0.net",
    "overwrite.cli.url": "https:\/\/notre.rez0.net\/",
    "updater.release.channel": "stable",
    "mail_smtpmode": "smtp",
    "mail_smtpsecure": "ssl",
    "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
    "davstorage.request_timeout": 3600,
    "dbpersistent": false,
    "appsallowlist": false,
    "maintenance_window_start": 100,
    "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
    "defaultapp": "",
    "auth.bruteforce.protection.enabled": true,
    "ratelimit.protection.enabled": true
}
</details>

Cron Configuration: Array
(
[backgroundjobs_mode] => cron
[lastcron] => 1725993214
)

External storages: files_external is disabled

Encryption: no

User-backends:

OC\User\Database

Talk configuration:

STUN servers

185.252.235.96:443

TURN servers

turn:185.252.235.96:3478 - udp,tcp

Signaling servers (mode: default):

SIP dialin is disabled

SIP dialout is disabled

https://notre.rez0.net/standalone-signaling/ - 1.3.2~docker

Recording servers:

Recording is enabled

Recording consent is set to "default"

no recording server configured

Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

[brakhane]

I stumbled upon a similiar issue and just post my findings here instead of making a new bug report.

The issue is that postgres does not allow NUL bytes in TEXT fields, however, CustomPropertiesBackend uses serialize to store non scalar values. Sabre's ResourceType has a private field in it, and serialize documentation states:

Object's private members have the class name prepended to the member name; protected members have a '*' prepended to the member name. These prepended values have null bytes on either side.

Also,

Note that this is a binary string which may include null bytes, and needs to be stored and handled as such. For example, serialize() output should generally be stored in a BLOB field in a database, rather than a CHAR or TEXT field.

The problem now is that we try to store that serialized value as-is, which Postgres doesn't support. One way to fix it would be to store non-text values base64 encoded, or alternatively, change the type of propertyvalue from TEXT to BLOB (or BYTEA) and store normal text as UTF-8 encoded blob and objects as-is.

Obviously this would require a database migration.

[joshtrichards]

Also see #37754 (comment)

[punkyard]

hi @joshtrichards
thanks for your reply

I have looked at #37754 and it seems to be about column type
when this issue here could be considered as a quantity error
what do you think?

[starlingfire]

Also experiencing this issue. I'm running Nextcloud Hub 9 (30.0.0) though the docker image Nextcloud AIO v9.6.0.

I see the below message spammed a ton of times in my log, right after I added my subscribed to my Nextcloud calendar via URL to a Google calendar.

[PHP] Error: unserialize(): Error at offset 61 of 64 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#560
	PROPFIND /remote.php/dav/calendars/[USER_REDACTED]/
	from [IP_REDACTED] by [USER_REDACTED] at Oct 10, 2024, 7:13:59 PM

[phil-lipp]

Also experiencing this issue. I'm running Nextcloud Hub 9 (30.0.0) though the docker image Nextcloud AIO v9.6.0.

I see the below message spammed a ton of times in my log, right after I added my subscribed to my Nextcloud calendar via URL to a Google calendar.

[PHP] Error: unserialize(): Error at offset 61 of 64 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#560
	PROPFIND /remote.php/dav/calendars/[USER_REDACTED]/
	from [IP_REDACTED] by [USER_REDACTED] at Oct 10, 2024, 7:13:59 PM

Same here, also on Hub 9 with Nextcloud AIO. I also have a Google Calendar subscription so that must be it. Calendar entries for that are showing up correctly tho

[susnux]

cc @miaulalala @SebastianKrupinski

[SebastianKrupinski]

Thanks for the heads up @susnux will have a look.