In the above report there are three different kinds of leaks were observed.

In 5.5:
=====
CURRENT_TEST: rpl.rpl_row_mysqlbinlog
================================================================
==8988==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 112 byte(s) in 1 object(s) allocated from:
#0 0x4eff87 in __interceptor_malloc (/dev/shm/5.5/client/mysqlbinlog+0x4eff87)
#1 0x60eaab in my_malloc /mariadb/5.5/mysys/my_malloc.c:41:10
#2 0x5300dd in Log_event::read_log_event(char const*, unsigned int, char const*, Format_description_log_event const, char) /mariadb/5.5/sql/log_event.cc:1568:12
#3 0x564a9c in dump_remote_log_entries(st_print_event_info*, char const*) /mariadb/5.5/client/mysqlbinlog.cc:1978:17
#4 0x536408 in dump_log_entries(char const*) /mariadb/5.5/client/mysqlbinlog.cc:1794:21
#5 0x535e4b in main /mariadb/5.5/client/mysqlbinlog.cc:2505:18
#6 0x7f71ea0a1b16 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x22b16)

This issue exists only in 5.5. It is specific to fake rotate events while reading binary log from a remote server.
This issues is already fixed in MariaDB 10.0.23 and higher versions as part of
commit c3018b0ff4fb02c029787d03867adf0530607bab

10.2 and above:
=============
1) Leak in Log_event::read_log_event(char const*, unsigned int, char const**,
Format_description_log_event const*, char)
File: sql/log_event.cc:2150
2) read_remote_annotate_event(unsigned char*, unsigned long, char const**)
File: client/mysqlbinlog.cc:194

These were caused because of flashback feature and its related bug fixes.

To reproduce the failures use:

ASAN_OPTIONS=abort_on_error=1 ./mtr --parallel=auto binlog.binlog_row_mysqlbinlog_verbose binlog_encryption.binlog_row_annotate binlog.binlog_row_mysqlbinlog_options binlog.binlog_row_annotate encryption.tempfiles binlog.binlog_mysqlbinlog_row_myisam binlog.binlog_mysqlbinlog_row binlog.binlog_mysqlbinlog_base64 binlog_encryption.rpl_skip_replication binlog.binlog_mysqlbinlog_row_innodb binlog.flashback

Hello Andrei,

Can you please review two different patches for MDEV-17260 fix.

For 5.5:
======
http://buildbot.askmonty.org/buildbot/grid?category=main&branch=bb-5.5-sujatha
https://github.com/MariaDB/server/commit/8b066a3d234e17249ca638a76cdd48a279633d34

For 10.2:
=======
http://buildbot.askmonty.org/buildbot/grid?category=main&branch=bb-10.2-sujatha
https://github.com/MariaDB/server/commit/fdf298c036fa0bb68fe3e2f0bfd28bf3b3f466d1

Thank you

Hello Andrei,

Thank you for the review comments.
I have added a test case which covers flashback and remote options.

I verified that the newly added test case fails without fix as shown below.

CURRENT_TEST: binlog.flashback

=================================================================
==26328==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 48 byte(s) in 1 object(s) allocated from:
#0 0x7f496b046b50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
#1 0x55a508dd102b in my_malloc /home/sujatha/bug_repo/MDEV-17260-10.2/mysys/my_malloc.c:101
#2 0x55a508c8d57e in read_remote_annotate_event(unsigned char*, unsigned long, char const**) /home/sujatha/bug_repo/MDEV-17260-10.2/client/mysqlbinlog.cc:194
#3 0x55a508c93c69 in handle_event_text_mode /home/sujatha/bug_repo/MDEV-17260-10.2/client/mysqlbinlog.cc:2285
#4 0x55a508c95fcf in dump_remote_log_entries /home/sujatha/bug_repo/MDEV-17260-10.2/client/mysqlbinlog.cc:2608
#5 0x55a508c9351b in dump_log_entries /home/sujatha/bug_repo/MDEV-17260-10.2/client/mysqlbinlog.cc:2162
#6 0x55a508c97b5b in main /home/sujatha/bug_repo/MDEV-17260-10.2/client/mysqlbinlog.cc:3098
#7 0x7f49698b4b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)

SUMMARY: AddressSanitizer: 48 byte(s) leaked in 1 allocation(s).
Aborted (core dumped)
mysqltest: At line 355: exec of '/home/sujatha/bug_repo/MDEV-17260-10.2/bld/client/mysqlbinlog --defaults-file=/home/sujatha/bug_repo/MDEV-17260-10.2/bld/mysql-test/var/2/my.cnf --local-load=/home/sujatha/bug_repo/MDEV-17260-10.2/bld/mysql-test/var/tmp/2 -vv -B --read-from-remote-server --user=root --host=127.0.0.1 --port=16020 master-bin.000002> /home/sujatha/bug_repo/MDEV-17260-10.2/bld/mysql-test/var/2/tmp/mysqlbinlog_row_flashback_4.sql' failed, error: 34304, status: 134, errno: 11
Output from before failure:
f

With fix it passes.

http://buildbot.askmonty.org/buildbot/grid?category=main&branch=bb-10.2-sujatha
https://github.com/MariaDB/server/commit/8ae7a5eb03725441393c353e4e203f80b666c035

Please review the new set of changes.

At the time for merging 10.2 patch into 10.3 please consider the following patch.

10.3: Changes.
https://github.com/MariaDB/server/commit/ddfd6297f8f7cf2009d326ae825c75c918fe8ef3

Merged to 10.3