Panic: file ostream.c: assertion failed when using mail_filter on RHEL8

Hi,

I installed dovecot on a new up-to-date RHEL8 test system and configured a simple mail_filter plugin which only copies the input back to the output (i.e., the filter does nothing special).

On RHEL8 I get the following panic when saving the mail. The Dovecot version that comes with RHEL8 is dovecot-2.3.8-4.el8.x86_64

The mail_filter works correctly on an Ubuntu machine )2.2.33.2- 1ubuntu4.7)

Any idea what's causing this panic on RHEL8 and how to fix it?

Kind regards,

Martijn Brinkers

Log output (panic log is at the bottom)

Apr 23 10:35:54 ciphermail-webmail dovecot[18680]: master: Dovecot v2.3.8 (9df20d2db) starting up for imap Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: Loading modules from directory: /usr/lib64/dovecot/auth Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/lib20_auth_var_expand_crypt.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: Read auth token secret from /var/run/dovecot/auth-token-secret.dat Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: auth client connected (pid=19771) Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: client in: AUTH 1 PLAIN service=imap secured se ssion=i7avXaHAuLh/AAAB lip=127.0.0.1 rip=127.0.0.1
lport=143 rport=47288 resp=<hidden> Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: dict( test@example.com,127.0.0.1,<i7avXaHAuLh/AAAB>): Performing passdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: Loading modules from directory: /usr/lib64/dovecot/auth Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: Module loaded: /usr/lib64/dovecot/auth/lib20_auth_var_expand_crypt.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: conn unix:auth-worker (pid=19773,uid=97): Server accepted connection (fd=13) Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: conn unix:auth-worker (pid=19773,uid=97): Sending version handshake Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: conn unix:auth-worker (pid=19773,uid=97): auth-worker<1>: Handling PASSV request Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: dict(test@example.com,127.0.0.1,<i7avXaHAuLh/AAAB>): Performing passdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: dict(test@example.com,127.0.0.1,<i7avXaHAuLh/AAAB>): Lookup: shared/passdb/test@example.com/test = {"userdb_email":"test@example.com ","userdb_quota_rule":"*:bytes=1073741824","password":"{SSHA256.b64}SF5 hEeUZVO4ydasqNb040KHWGyin791L40BYR8cXf+I0EGeetzq5Cg==","userdb_password ":"test","userdb_home":" /var/vmail/test=40example.com@ciphermail.private","user":" test=40example.com@ciphermail.private"} Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: dict(test@example.com,127.0.0.1,<i7avXaHAuLh/AAAB>): username changed test@example.com -> test=40example.com@ciphermail.private Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: dict(test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuL h/AAAB>): Finished passdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth-worker(19774): Debug: conn unix:auth-worker (pid=19773,uid=97): auth-worker<1>: Finished Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: dict( test@example.com,127.0.0.1,<i7avXaHAuLh/AAAB>): username changed test@example.com -> test=40example.com@ciphermail.private Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: dict( test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuLh/AAAB>): Finished passdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: auth( test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuLh/AAAB>): Auth request finished Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: client passdb out: OK 1
user=test=40example.com@ciphermail.private
original_user=test@example.com Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: master in: REQUEST 3373400065 19771 1 603cbf25103fc9a6 77ceabe45f077e40 session_pid=19776 request_auth_token Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: prefetch(test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuLh/A AAB>): Performing userdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: prefetch(test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuLh/A AAB>): success Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: prefetch(test=40example.com@ciphermail.private,127.0.0.1,<i7avXaHAuLh/A AAB>): Finished userdb lookup Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: auth: Debug: master userdb out: USER 3373400065
test=40example.com@ciphermail.private email=test@example.com
quota_rule=*:bytes=1073741824 password=<hidden>
home=/var/vmail/test=40example.com@ciphermail.private auth_mech= PLAIN auth_token=819d2ad4117e4e4139991fab046e13304880e935
auth_user=test@example.com Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap-login: Login: user=<test=40example.com@ciphermail.private>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=19776, secured, session=<i7avXaHAuLh/AAAB> Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Loading modules from directory: /usr/lib64/dovecot Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Module loaded: /usr/lib64/dovecot/lib10_mail_filter_plugin.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Module loaded: /usr/lib64/dovecot/lib10_quota_plugin.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Module loaded: /usr/lib64/dovecot/lib11_imap_quota_plugin.so Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Added userdb setting: plugin/auth_mech=PLAIN Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Added userdb setting: plugin/email=test@example.com Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Added userdb setting: plugin/password=<hidden> Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Added userdb setting: plugin/quota_rule=*:bytes=1073741824 Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Effective uid=986, gid=983, home=/var/vmail/test=40example.com@ciphermail.private Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: mail_filter: Filtering mail_filter via socket /var/run/dovecot/mail- filter Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: mail_filter: Filtering mail_filter_out via socket /var/run/dovecot/mail-filter-out Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Quota root: name=User quota backend=maildir args= Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Quota rule: root=User quota mailbox=* bytes=1073741824 messages=0 Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Quota rule: root=User quota mailbox=Trash bytes=+107374182 (10%) messages=0 Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Quota grace: root=User quota bytes=107374182 (10%) Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: maildir++: root=/var/vmail/test=40example.com@ciphermail.private, index=, indexpvt=, control=, inbox=/var/vmail/test=40example.com@ciphermail.private, alt= Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: quota: quota_over_flag check: quota_over_script unset - skipping Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Debug: Mailbox Drafts: Mailbox opened because: APPEND Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Panic: file ostream.c: line 201 (o_stream_flush): assertion failed: (stream-

stream_errno != 0) Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap( test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0(+0xf895b) [0x7f8f1d3d995b] -> /usr/lib64/dovecot/libdovecot.so.0(+0xf89f7) [0x7f8f1d3d99f7] -> /usr/lib64/dovecot/libdovecot.so.0(+0x55b05) [0x7f8f1d336b05] -> /usr/lib64/dovecot/libdovecot.so.0(+0x5a1bd) [0x7f8f1d33b1bd] -> /usr/lib64/dovecot/libdovecot- storage.so.0(maildir_save_finish+0x99) [0x7f8f1d723fa9] -> /usr/lib64/dovecot/lib10_quota_plugin.so(+0xfcee) [0x7f8f1bd5acee] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mailbox_save_finish+0x7d) [0x7f8f1d6fafdd] -> dovecot/imap(+0x132fd) [0x564a032332fd] -> dovecot/imap(command_exec+0x78) [0x564a03241cd8] -> dovecot/imap(+0x128ad) [0x564a032328ad] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_call_io+0x73) [0x7f8f1d3f10c3] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x135) [0x7f8f1d3f2775] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run+0x50) [0x7f8f1d3f1170] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_run+0x48) [0x7f8f1d3f12d8] -> /usr/lib64/dovecot/libdovecot.so.0(master_service_run+0x17) [0x7f8f1d368eb7] -> dovecot/imap(main+0x335) [0x564a03232445] -> /lib64/libc.so.6(__libc_start_main+0xf3) [0x7f8f1ca5b803] -> dovecot/imap(_start+0x2e) [0x564a032325fe] Apr 23 10:36:17 ciphermail-webmail dovecot[18682]: imap(test=40example.com@ciphermail.private)<19776><i7avXaHAuLh/AAAB>: Fatal: master: service(imap): child 19776 killed with signal 6 (core not dumped - https://dovecot.org/bugreport.html#coredumps - set /proc/sys/fs/suid_dumpable to 2)