Sabre\DAV\Exception\NotFound exception in PROPFIND response when file does not have a read permission bit

I have been unable to find out how the affected file ends up with no read permission bit set on it to start with, but have been able to replicate it by manually removing the read permission that is set in the oc_filecache.

Steps to reproduce

1. Create a directory
2. Upload a file (multiple is better)
3. Remove the read permission from the file
4. Perform a PROPFIND on the directory

Example using owncloud/server:10.11 docker image

# start the owncloud container and wait for it to start
docker run --rm --name ocpropfind -d -e OWNCLOUD_DOMAIN=localhost:8080 -p8080:8080 owncloud/server:10.11
# run a propfind so that the user's skeleton storage get's created
docker exec ocpropfind curl -s --user admin:admin http://127.0.0.1:8080/remote.php/webdav/Photos -X PROPFIND >/dev/null 2>&1
# remove the read permission from a file
docker exec ocpropfind sqlite3 /mnt/data/files/owncloud.db 'update oc_filecache set permissions=26 where path="files/Photos/Lake-Constance.jpg";'
# perform a propfind to get an exception in the response
docker exec ocpropfind curl -s --user admin:admin http://127.0.0.1:8080/remote.php/webdav/Photos -X PROPFIND

Expected behaviour

There should be no exception in the PROPFIND response.

Actual behaviour

A Sabre\DAV\Exception\NotFound exception is printed mid-PROPFIND response making the response invalid.

The behaviour of the client varies.

• Chrome will list files up to the exception.
• Firefox does not list the parent directory at all.
• ownCloud sync client presents an "Unknown error" and does not continue syncing files.

<?xml version="1.0"?>
<d:multistatus xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns" xmlns:oc="http://owncloud.org/ns"><d:response><d:href>/remote.php/webdav/Photos/</d:href><d:propstat><d:prop><d:getlastmodified>Mon, 31 Oct 2022 01:11:44 GMT</d:getlastmodified><d:resourcetype><d:collection/></d:resourcetype><d:quota-used-bytes>1011464</d:quota-used-bytes><d:quota-available-bytes>-3</d:quota-available-bytes><d:getetag>&quot;635f20d04519e&quot;</d:getetag></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response><?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns">
  <s:exception>Sabre\DAV\Exception\NotFound</s:exception>
  <s:message/>
</d:error>

Server configuration

Example above uses a fresh owncloud/server:10.11 docker image with no changes.

Logs

Web server error log

[Mon Oct 31 01:11:42.398393 2022] [mpm_prefork:notice] [pid 161] AH00163: Apache/2.4.41 (Ubuntu) configured -- resuming normal operations
[Mon Oct 31 01:11:42.398437 2022] [core:notice] [pid 161] AH00094: Command line: '/usr/sbin/apache2 -f /etc/apache2/apache2.conf -D FOREGROUND'
127.0.0.1 - admin [31/Oct/2022:01:11:43 +0000] "PROPFIND /remote.php/webdav/Photos HTTP/1.1" 207 2810 "-" "curl/7.68.0"
127.0.0.1 - admin [31/Oct/2022:01:12:00 +0000] "PROPFIND /remote.php/webdav/Photos HTTP/1.1" 207 1750 "-" "curl/7.68.0"

ownCloud log (data/owncloud.log)

{"reqId":"fKqktKk5TSB79JpvZAZw","level":3,"time":"2022-10-31T01:12:00+00:00","remoteAddr":"127.0.0.1","user":"admin","app":"PHP","method":"PROPFIND","url":"\/remote.php\/webdav\/Photos","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Message.php:117) at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Sapi.php#66"}
{"reqId":"fKqktKk5TSB79JpvZAZw","level":3,"time":"2022-10-31T01:12:00+00:00","remoteAddr":"127.0.0.1","user":"admin","app":"PHP","method":"PROPFIND","url":"\/remote.php\/webdav\/Photos","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Message.php:117) at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Sapi.php#70"}
{"reqId":"fKqktKk5TSB79JpvZAZw","level":3,"time":"2022-10-31T01:12:00+00:00","remoteAddr":"127.0.0.1","user":"admin","app":"PHP","method":"PROPFIND","url":"\/remote.php\/webdav\/Photos","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Message.php:117) at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Sapi.php#70"}
{"reqId":"fKqktKk5TSB79JpvZAZw","level":3,"time":"2022-10-31T01:12:00+00:00","remoteAddr":"127.0.0.1","user":"admin","app":"PHP","method":"PROPFIND","url":"\/remote.php\/webdav\/Photos","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Message.php:117) at \/var\/www\/owncloud\/lib\/composer\/sabre\/http\/lib\/Sapi.php#70"}