This is actually happening when adding/deleting a route-map which is already
assigned to the peer, e.g.:

```
vtysh -c 'enable' -c 'config terminal' -c 'route-map 1735210719119015328 permit 10' -c 'set local-preference 100' -c end
vtysh -c 'enable' -c 'clear ip bgp vrf default 10.10.10.20 soft'
vtysh -c 'enable' -c 'config terminal' -c 'no route-map 1735210719119015328' -c end
vtysh -c 'enable' -c 'config terminal' -c 'route-map 1735210719119015328 permit 10' -c 'set local-preference 100' -c end
vtysh -c 'enable' -c 'config terminal' -c 'no route-map 1735210719119015328' -c end
vtysh -c 'enable' -c 'config terminal' -c 'route-map 1735210719119015328 permit 10' -c 'set local-preference 100' -c end
exabgpcli announce route 10.0.104.0/24 next-hop self
```

This results in:

```
==51773==ERROR: AddressSanitizer: heap-use-after-free on address 0x50c00009da88 at pc 0x73aaa151af77 bp 0x7ffeba229410 sp 0x7ffeba229400
READ of size 8 at 0x50c00009da88 thread T0
0 0x73aaa151af76 in route_map_apply_ext lib/routemap.c:2593
1 0x6288268ad13c in bgp_input_modifier bgpd/bgp_route.c:1927
2 0x6288268c759d in bgp_update bgpd/bgp_route.c:5233
3 0x6288268d5bb4 in bgp_nlri_parse_ip bgpd/bgp_route.c:7305
4 0x62882684df88 in bgp_nlri_parse bgpd/bgp_packet.c:338
5 0x62882685eb28 in bgp_update_receive bgpd/bgp_packet.c:2462
6 0x62882686f071 in bgp_process_packet bgpd/bgp_packet.c:4089
7 0x73aaa159db5e in event_call lib/event.c:2005
8 0x73aaa13f8b63 in frr_run lib/libfrr.c:1252
9 0x62882667d705 in main bgpd/bgp_main.c:565
10 0x73aaa0c2a1c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
11 0x73aaa0c2a28a in __libc_start_main_impl ../csu/libc-start.c:360
12 0x628826678844 in _start (/usr/lib/frr/bgpd+0x4af844) (BuildId: a3f60fa98b856e76fb8a57aaf29d053f28e1b78c)
0x50c00009da88 is located 8 bytes inside of 128-byte region [0x50c00009da80,0x50c00009db00)
freed by thread T0 here:
0 0x73aaa1cfc4d8 in free ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:52
1 0x73aaa143a392 in qfree lib/memory.c:136
2 0x73aaa150fdf0 in route_map_free_map lib/routemap.c:748
3 0x73aaa150f5dc in route_map_add lib/routemap.c:672
4 0x73aaa15108e5 in route_map_get lib/routemap.c:857
5 0x73aaa1538c83 in lib_route_map_create lib/routemap_northbound.c:102
6 0x73aaa14958e9 in nb_callback_create lib/northbound.c:1547
7 0x73aaa1499c3e in nb_callback_configuration lib/northbound.c:1958
8 0x73aaa149a9fd in nb_transaction_process lib/northbound.c:2091
9 0x73aaa1494646 in nb_candidate_commit_apply lib/northbound.c:1409
10 0x73aaa1494a21 in nb_candidate_commit lib/northbound.c:1449
11 0x73aaa14aaf3d in nb_cli_classic_commit lib/northbound_cli.c:57
12 0x73aaa14ac226 in nb_cli_apply_changes_internal lib/northbound_cli.c:195
13 0x73aaa14acaa5 in _nb_cli_apply_changes lib/northbound_cli.c:251
14 0x73aaa14acdb5 in nb_cli_apply_changes lib/northbound_cli.c:267
15 0x73aaa152dac3 in route_map_magic lib/routemap_cli.c:49
16 0x73aaa1520e2b in route_map lib/routemap_cli_clippy.c:69
17 0x73aaa132fe4a in cmd_execute_command_real lib/command.c:1010
18 0x73aaa13302e9 in cmd_execute_command lib/command.c:1069
19 0x73aaa133142e in cmd_execute lib/command.c:1235
20 0x73aaa15b354e in vty_command lib/vty.c:617
21 0x73aaa15b95a0 in vty_execute lib/vty.c:1380
22 0x73aaa15c146b in vtysh_read lib/vty.c:2391
23 0x73aaa159db5e in event_call lib/event.c:2005
24 0x73aaa13f8b63 in frr_run lib/libfrr.c:1252
25 0x62882667d705 in main bgpd/bgp_main.c:565
26 0x73aaa0c2a1c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
27 0x73aaa0c2a28a in __libc_start_main_impl ../csu/libc-start.c:360
28 0x628826678844 in _start (/usr/lib/frr/bgpd+0x4af844) (BuildId: a3f60fa98b856e76fb8a57aaf29d053f28e1b78c)
previously allocated by thread T0 here:
0 0x73aaa1cfd340 in calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:77
1 0x73aaa143a126 in qcalloc lib/memory.c:111
2 0x73aaa150f424 in route_map_new lib/routemap.c:646
3 0x73aaa150f4ed in route_map_add lib/routemap.c:658
4 0x73aaa15108e5 in route_map_get lib/routemap.c:857
5 0x73aaa1538c83 in lib_route_map_create lib/routemap_northbound.c:102
6 0x73aaa14958e9 in nb_callback_create lib/northbound.c:1547
7 0x73aaa1499c3e in nb_callback_configuration lib/northbound.c:1958
8 0x73aaa149a9fd in nb_transaction_process lib/northbound.c:2091
9 0x73aaa1494646 in nb_candidate_commit_apply lib/northbound.c:1409
10 0x73aaa1494a21 in nb_candidate_commit lib/northbound.c:1449
11 0x73aaa14aaf3d in nb_cli_classic_commit lib/northbound_cli.c:57
12 0x73aaa14ac226 in nb_cli_apply_changes_internal lib/northbound_cli.c:195
13 0x73aaa14acaa5 in _nb_cli_apply_changes lib/northbound_cli.c:251
14 0x73aaa14acdb5 in nb_cli_apply_changes lib/northbound_cli.c:267
15 0x73aaa152dac3 in route_map_magic lib/routemap_cli.c:49
16 0x73aaa1520e2b in route_map lib/routemap_cli_clippy.c:69
17 0x73aaa132fe4a in cmd_execute_command_real lib/command.c:1010
18 0x73aaa13302e9 in cmd_execute_command lib/command.c:1069
19 0x73aaa133142e in cmd_execute lib/command.c:1235
20 0x73aaa15b354e in vty_command lib/vty.c:617
21 0x73aaa15b95a0 in vty_execute lib/vty.c:1380
22 0x73aaa15c146b in vtysh_read lib/vty.c:2391
23 0x73aaa159db5e in event_call lib/event.c:2005
24 0x73aaa13f8b63 in frr_run lib/libfrr.c:1252
25 0x62882667d705 in main bgpd/bgp_main.c:565
26 0x73aaa0c2a1c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
27 0x73aaa0c2a28a in __libc_start_main_impl ../csu/libc-start.c:360
28 0x628826678844 in _start (/usr/lib/frr/bgpd+0x4af844) (BuildId: a3f60fa98b856e76fb8a57aaf29d053f28e1b78c)
```

Signed-off-by: Donatas Abraitis <[email protected]>
(cherry picked from commit f4f5c34)