April 2026 - dovecot - dovecot.org

dovecot.list.index.log owned by root: why?
by Stefan G. Weichinger 01 Apr '26

01 Apr '26

I use these sql-queries to let all mailboxes be accessed by the uid=1001: passdb sql { default_password_scheme = MD5-CRYPT passdb_sql_query = SELECT username as user, password, \ '/home/vmail/%{user | domain }/%{user}' as userdb_home, 'maildir:/home/vmail/%{user | domain }/%{user}' as userdb_mail,\ 1001 as userdb_uid, 1001 as userdb_gid FROM mailbox WHERE username = '%{user}' AND active = '1' } userdb prefetch { } ( I assume this following query isn't used then anymore) userdb sql { userdb_sql_query = SELECT username as user, password, \ '/home/vmail/%{user | domain }/%{user}' as userdb_home, 'maildir:/home/vmail/%{user | domain }/%{user}' as userdb_mail,\ 1001 as userdb_uid, 1001 as userdb_gid \ FROM mailbox WHERE username = '%{user}' AND active = '1' userdb_sql_iterate_query = SELECT userid AS username, domain FROM users } id 1001 uid=1001(vmail) gid=1001(vmail) groups=1001(vmail),118(dovecot) I get errors like: Apr 01 11:43:05 imap(logs(a)xunil.at)<1564491><N8oZ6WJO/uwgAQRwHwsMRX9ul+gRMpfY>: Error: open(/home/vmail/xunil.at/logs(a)xunil.at/dovecot.list.index.log) failed: Permission denied (euid=1001(vmail) egid=1001(vmail) missing +r perm: /home/vmail/xunil.at/logs(a)xunil.at/dovecot.list.index.log) ls -l /home/vmail/xunil.at/logs(a)xunil.at/ total 944 drwx------ 2 vmail vmail 622592 Apr 1 11:43 cur -rw------- 1 vmail vmail 0 Jul 30 2021 dovecot-acl-list -rw------- 1 vmail vmail 3304 Apr 1 11:35 dovecot.index -rw------- 1 vmail vmail 202444 Apr 1 11:43 dovecot.index.cache -rw------- 1 vmail vmail 2908 Apr 1 11:43 dovecot.index.log -rw------- 1 vmail vmail 32892 Apr 1 11:35 dovecot.index.log.2 -rw------- 1 vmail vmail 91 Feb 9 2024 dovecot-keywords -rw------- 1 root root 5744 Apr 1 10:30 dovecot.list.index -rw------- 1 root root 480 Apr 1 10:52 dovecot.list.index.log [..] Why do these 2 files get owned by root now ... ? All files below "/home/vmail" should be owned by vmail:vmail I ran chown, and chgrp, sure .. but the errors return. How to fix this? Thanks in advance!

2 5

cannot get IOS or MacOSX to connect to dovecot:995 since upgraded Mac or iPhone
by Bill Scheding 01 Apr '26

01 Apr '26

Versions: [wls(a)www.wls.org]$ uname -a Linux www.wls.org 3.10.0-1160.119.1.el7.x86_64 #1 SMP Tue Jun 4 14:43:51 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux [wls(a)ww.wls.org]$ dovecot --version 2.2.36 (1f10bfa63) My Certs: Testing cert dovecot.key unable to load certificate 139668060415888:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:707:Expecting: TRUSTED CERTIFICATE lrwxrwxrwx 1 root root 21 Mar 25 15:44 dovecot.key -> dovecot.key.old_sep_2 Testing chain dovecot.pem SHA1 Fingerprint=4A:29:34:1D:D5:9C:67:59:FA:31:7E:FF:F4:53:F8:DB:25:73:15:07 subject= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com issuer= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com serial=C8AA4C688A3F2638 b5bd7939 notBefore=Sep 2 20:17:33 2018 GMT notAfter=Sep 2 20:17:33 2019 GMT lrwxrwxrwx 1 root root 21 Mar 25 15:44 dovecot.pem -> dovecot.crt.old_sep_2 New Certs: Testing key ca.key.3.13.4 RSA key ok lrwxrwxrwx 1 root root 31 Mar 13 14:14 ca.key.3.13.4 -> ../../tls/private/ca.key.3.13.4 Testing chain ca.crt.3.13.4 SHA1 Fingerprint=79:69:88:2A:E0:BF:58:A8:21:E3:88:12:8D:45:20:4F:FD:68:33:63 subject= /C=XX/ST= /L= /O= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com issuer= /C=XX/ST= /L= /O= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com serial=B912DD19FEDC441C 402b4e2a notBefore=Mar 13 20:02:58 2026 GMT notAfter=Mar 13 20:02:58 2027 GMT lrwxrwxrwx 1 root root 29 Mar 13 14:13 ca.crt.3.13.4 -> ../../tls/certs/ca.crt.3.13.4 They install OK, dovecot starts; but iPhone and mac cannot connect to pop3 Cannot get my iPhone or Mac to accept new certs from lets encrypt, et. al. This is a new problem, started recently. My existing cert expired in 2016 William

2 1

Variable expansion syntax: Filter "default" throws error (unwanted)
by Johannes Nohl 01 Apr '26

01 Apr '26

I am using dovecot 2.4.2 (almost) with new config language and I have a working configuration. However, the check for disabled users throws permanently errors in the log file, whenever a user is missing the ldap attribute for disabled. This is - in my view - due to a misfunction of Filter "default". passdb ldap { driver = ldap ldap_bind = yes ldap_filter = (&(|(objectClass=posixAccount)(objectClass=mailAccount))(uid=%{user})) fields { user = %{ldap:uid} nologin = %{ldap:shadowInactive | default(null)} reason = The account for this email address is disabled. } } This results in the following log line: 2026-03-31T00:46:31.102690+02:00 mailserver dovecot: auth(test,ipv4,sasl:plain)<YE81n0VOVuofEeSD>: Error: ldap: auth_passdb_post settings: Failed to parse configuration: Failed to expand passdb_fields/nologin setting variables: ldap: No such attribute 'shadowinactive' The right behaviour would be no logging on login success. Because the Filter "default" is intended to suppress any errors ("When value is missing or empty, you can use the default filter to provide value. Missing variables will cause errors and must be negated with default. This does not apply to all providers, some providers return empty when value is missing."). https://doc.dovecot.org/2.4.2/core/settings/variables.html#variable-expansi… As you may have seen I had to borrow null-value from sql db config also to make nologin ignoring a non present attribute. This is undocumented obviously. Instead, a non-working tip is provided ("Changed: 2.4.0 Extra fields can now also be set to empty string, "). However, the following does not work: "nologin = {ldap:shadowinactive | default("")}". https://doc.dovecot.org/2.4.2/core/settings/variables.html Also, the documentation is missing/hiding the part which explains that "default()" can be used to avoid error logs. PR regarding the documentation source is sent already. See "Fails if the attribute is not present, unless the ` <missing part>" https://doc.dovecot.org/2.4.0/core/config/auth/databases/ldap.html#ldap-spe… Is there another way to verify if account is disabled? -- Johannes Nohl postmaster i-t-cloud -- Johannes Nohl postmaster(a)i-t-cloud.de I am using dovecot 2.4.2 (almost) with new config language and I have a working configuration. However, the check for disabled users throws permanently errors in the log file, whenever a user is missing the ldap attribute for disabled. This is - in my view - due to a misfunction of Filter "default". passdb ldap { driver = ldap ldap_bind = yes ldap_filter = (&(|(objectClass=posixAccount)(objectClass=mailAccount))(uid=%{user})) fields { user = %{ldap:uid} nologin = %{ldap:shadowInactive | default(null)} reason = The account for this email address is disabled. } } This results in the following log line: *2026-03-31T00:46:31.102690+02:00 mailserver dovecot: auth(test,ipv4,sasl:plain)<YE81n0VOVuofEeSD>: Error: ldap: auth_passdb_post settings: Failed to parse configuration: Failed to expand passdb_fields/nologin setting variables: ldap: No such attribute 'shadowinactive' The right behaviour would be no logging on login success. Because the Filter "default" is intended to suppress any errors ("When value is missing or empty, you can use the default filter to provide value. Missing variables will cause errors and must be negated with default. This does not apply to all providers, some providers return empty when value is missing."). https://doc.dovecot.org/2.4.2/core/settings/variables.html#variable-expansi… As you may have seen I had to borrow null-value from sql db config also to make nologin ignoring a non present attribute. This is undocumented obviously. Instead, a non-working tip is provided ("Changed: 2.4.0 Extra fields can now also be set to empty string, "). However, the following does not work: "nologin = {ldap:shadowinactive | default("")}". https://doc.dovecot.org/2.4.2/core/settings/variables.html Also, the documentation is missing/hiding the part which explains that "default()" can be used to avoid error logs. PR regarding the documentation source is sent already. See "Fails if the attribute is not present, unless the ` <missing part>" https://doc.dovecot.org/2.4.0/core/config/auth/databases/ldap.html#ldap-spe… Is there another way to verify if account is disabled? -- Johannes Nohl postmaster i-t-cloud -- Johannes Nohl postmaster(a)i-t-cloud.de

2 1

[BUG] 2.4.3 SIGSEGV in fts_solr
by Nick O'Connor 01 Apr '26

01 Apr '26

Dovecot 2.4.3 crashes with SIGSEGV in indexer-worker and lmtp during FTS Solr indexing. The crash is a use-after-free triggered when the HTTP client does a DNS lookup for the Solr host. Environment: - Dovecot 2.4.3 (Alpine 3.23 / musl) - Linux x86_64 - Filesystem: maildir on ZFS - Solr 10.0.0 - fts_solr plugin with DNS-based Solr URL dovecot -n: # 2.4.3 (e278b1e09b): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.3 (0bf9ee48) # OS: Linux 6.12.74+deb13+1-amd64 x86_64 dovecot_config_version = 2.4.0 auth_mechanisms = oauthbearer xoauth2 dovecot_storage_version = 2.4.0 fts_autoindex = yes fts_search_add_missing = yes mail_always_cache_fields = date.save mail_driver = maildir mail_plugins { fts = yes fts_solr = yes } protocols = imap lmtp sieve ssl = required fts solr { url = http://solr.example.com/solr/dovecot } (LDAP userdb/passdb, pigeonhole sieve, imapsieve for spam learning, and oauth2 passdb omitted) How to reproduce: The crash occurs in the indexer-worker when processing multiple user mailboxes sequentially for FTS indexing, using a DNS hostname for the Solr URL. Steps: 1. Configure fts_solr with a DNS-based URL (not an IP address) 2. Have the indexer-worker process mailboxes for more than one user (e.g. fts_autoindex = yes with multiple users, or manual doveadm index -A) 3. The first user session completes successfully. On the second user session, the indexer-worker crashes with SIGSEGV during the DNS lookup for the Solr host. Reproduces reliably on musl (Alpine) due to aggressive memory reuse. Likely also affects glibc but may not crash immediately due to delayed reuse of freed memory. Root cause: The solr_http_client singleton outlives the user session that created it. Its event chain holds a ref on the mail_storage_service_user event, keeping it alive after the user is freed. The SETTINGS_EVENT_INSTANCE on that event still points to the already-freed settings_instance. On the next user session, dns_lookup() walks the stale event chain and dereferences the dangling pointer in settings_instance_get(). Stack trace (from core dump, debug build with musl-dbg): #0 strlen(s=0x415641d189485741) -- SIGSEGV, freed/reused memory #1 p_strdup() strfuncs.c:56 #2 event_add_str(key="protocol", value=...) lib-event.c:1099 #3 settings_instance_get() settings.c:2521 #4 settings_get_real() settings.c:2706 #5 settings_get_full() settings.c:2915 #6 settings_get(dns_client_setting_parser_info) settings.c:2976 #7 dns_client_init() dns-lookup.c:465 #8 dns_client_init_handle_failure() dns-lookup.c:317 #9 dns_lookup("solr.example.com") dns-lookup.c:337 #10 http_client_host_shared_lookup() http-client-host.c:166 #11 http_client_host_shared_refresh() http-client-host.c:195 #12-#19 http_client queue/host/request submit chain #20 http_client_request_continue_payload() http-client-request.c:1170 #21 http_client_request_send_payload() http-client-request.c:1261 #22 solr_connection_post_more() solr-connection.c:269 Proposed fix: Destroy solr_http_client in solr_connection_deinit() so it is recreated with a fresh event chain on the next user session: --- a/src/plugins/fts-solr/solr-connection.c +++ b/src/plugins/fts-solr/solr-connection.c @@ -117,6 +117,8 @@ void solr_connection_deinit(struct solr_connection **_conn) *_conn = NULL; event_unref(&conn->event); + if (solr_http_client != NULL) + http_client_deinit(&solr_http_client); i_free(conn->http_host); i_free(conn->http_base_url); I've been running for few days with the patch applied. FTS indexing across multiple user sessions completes without crashes using a DNS-based Solr URL. Please let me know if there's anything else that would be helpful. The core files have sensitive information so I've omitted them from the report. -Nick Dovecot 2.4.3 crashes with SIGSEGV in indexer-worker and lmtp during FTS Solr indexing. The crash is a use-after-free triggered when the HTTP client does a DNS lookup for the Solr host. Environment: - Dovecot 2.4.3 (Alpine 3.23 / musl) - Linux x86_64 - Filesystem: maildir on ZFS - Solr 10.0.0 - fts_solr plugin with DNS-based Solr URL dovecot -n: # 2.4.3 (e278b1e09b): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.3 (0bf9ee48) # OS: Linux 6.12.74+deb13+1-amd64 x86_64 dovecot_config_version = 2.4.0 auth_mechanisms = oauthbearer xoauth2 dovecot_storage_version = 2.4.0 fts_autoindex = yes fts_search_add_missing = yes mail_always_cache_fields = date.save mail_driver = maildir mail_plugins { fts = yes fts_solr = yes } protocols = imap lmtp sieve ssl = required fts solr { url = http://solr.example.com/solr/dovecot } (LDAP userdb/passdb, pigeonhole sieve, imapsieve for spam learning, and oauth2 passdb omitted) How to reproduce: The crash occurs in the indexer-worker when processing multiple user mailboxes sequentially for FTS indexing, using a DNS hostname for the Solr URL. Steps: 1. Configure fts_solr with a DNS-based URL (not an IP address) 2. Have the indexer-worker process mailboxes for more than one user (e.g. fts_autoindex = yes with multiple users, or manual doveadm index -A) 3. The first user session completes successfully. On the second user session, the indexer-worker crashes with SIGSEGV during the DNS lookup for the Solr host. Reproduces reliably on musl (Alpine) due to aggressive memory reuse. Likely also affects glibc but may not crash immediately due to delayed reuse of freed memory. Root cause: The solr_http_client singleton outlives the user session that created it. Its event chain holds a ref on the mail_storage_service_user event, keeping it alive after the user is freed. The SETTINGS_EVENT_INSTANCE on that event still points to the already-freed settings_instance. On the next user session, dns_lookup() walks the stale event chain and dereferences the dangling pointer in settings_instance_get(). Stack trace (from core dump, debug build with musl-dbg): #0 strlen(s=0x415641d189485741) -- SIGSEGV, freed/reused memory #1 p_strdup() strfuncs.c:56 #2 event_add_str(key="protocol", value=...) lib-event.c:1099 #3 settings_instance_get() settings.c:2521 #4 settings_get_real() settings.c:2706 #5 settings_get_full() settings.c:2915 #6 settings_get(dns_client_setting_parser_info) settings.c:2976 #7 dns_client_init() dns-lookup.c:465 #8 dns_clien t_init_handle_failure() dns-lookup.c:317 #9 dns_lookup("solr.example.com") dns-lookup.c:337 #10 http_client_host_shared_lookup() http-client-host.c:166 #11 http_client_host_shared_refresh() http-client-host.c:195 #12-#19 http_client queue/host/request submit chain #20 http_client_request_continue_payload() http-client-request.c:1170 #21 http_client_request_send_payload() http-client-request.c:1261 #22 solr_connection_post_more() solr-connection.c:269 Proposed fix: Destroy solr_http_client in solr_connection_deinit() so it is recreated with a fresh event chain on the next user session: --- a/src/plugins/fts-solr/solr-connection.c +++ b/src/plugins/fts-solr/solr-connection.c @@ -117,6 +117,8 @@ void solr_connection_deinit(struct solr_connection **_conn) *_conn = NULL; event_unref(&conn->event); + if (solr_http_client != NULL) + http_client_deinit(&solr_http_client); i_free(conn->http_host); i_free(conn->http_base_url); I've been running for few days with the patch applied. FTS indexing across multiple user sessions completes without crashes using a DNS-based Solr URL. Please let me know if there's anything else that would be helpful. The core files have sensitive information so I've omitted them from the report. -Nick

1 0