After pressing the flows button ntopng crashes

[AngeloColucci]

Hello,
on our ntopng server we get the following error when click on flows menu:

Mar 24 15:13:45 ntopng-poc kernel: [600665.356300] ntopng[35951]: segfault at 7f3f8070ff10 ip 000056505db08a0f sp 00007f3e92c84cd0 error 6 in ntopng[56505d9a2000+453000]
Mar 24 15:13:46 ntopng-poc systemd[1]: ntopng.service: Main process exited, code=killed, status=11/SEGV
Mar 24 15:13:46 ntopng-poc systemd[1]: ntopng.service: Failed with result 'signal'.

Following the Ntopng version used:

Version: 4.3.210324 [Enterprise/Professional build]
GIT rev: dev:728ee37f4cfc7d12286f54dbd0b08cc10af13735:20210324
Pro rev: r3654
Built on: Ubuntu 18.04.5 LTS
System Id: 5D536F36B208AA8F
Platform: x86_64
Edition: Enterprise M
License Type: Permanent

I have attached the ntopng.conf. I've removed our subnet:

ntopng.conf.txt

[MatteoBiscosi]

Hi @AngeloColucci I'm sorry but i'm unable to reproduce this issue, so please download this binary with debug symbols
https://www.dropbox.com/s/ddi7gjw39nhbr65/ntopng?dl=0
Run it in gdb as you normally do:
gdb --args /etc/ntopng/ntopng.conf
Then run it and wait until it crashes. When it crashes type 'bt' inside the (gdb) prompt and send me the output.
You can find detailed instructions here

[AngeloColucci]

Hi Matteo,
following the output in gdb after segmentation fault, and the bt:

Thread 13 "ntopng" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc67fc700 (LWP 40927)]
nDPIStats::incStats (this=this@entry=0x7fffc67f4650, when=when@entry=0, proto_id=proto_id@entry=3, sent_packets=, sent_bytes=, rcvd_packets=, rcvd_bytes=0) at src/nDPIStats.cpp:267
267 src/nDPIStats.cpp: No such file or directory.
(gdb) bt
#0 nDPIStats::incStats (this=this@entry=0x7fffc67f4650, when=when@entry=0, proto_id=proto_id@entry=3, sent_packets=, sent_bytes=, rcvd_packets=, rcvd_bytes=0) at src/nDPIStats.cpp:267
#1 0x000055555565aaa9 in Flow::sumStats (this=this@entry=0x7ffeee06bfd0, ndpi_stats=ndpi_stats@entry=0x7fffc67f4650, status_stats=status_stats@entry=0x7fffc67f3f10) at src/Flow.cpp:2389
#2 0x00005555556683f5 in flow_sum_stats (flow=0x7ffeee06bfd0, user_data=, matched=0x7fffc67f3dc7) at src/NetworkInterface.cpp:4482
#3 0x0000555555639045 in GenericHash::walk (this=0x555559bac8c0, begin_slot=0x7fffc67f3e1c, walk_all=true, walker=0x5555556683c0 <flow_sum_stats(GenericHashEntry*, void*, bool*)>, user_data=0x7fffc67f3e20) at src/GenericHash.cpp:222
#4 0x000055555566da3a in NetworkInterface::getActiveFlowsStats (this=this@entry=0x55555667e460, ndpi_stats=ndpi_stats@entry=0x7fffc67f4650, stats=stats@entry=0x7fffc67f3f10, allowed_hosts=0x7fffc67f6440, h=h@entry=0x0,
p=p@entry=0x7fffb455d710) at src/NetworkInterface.cpp:4508
#5 0x000055555568f422 in ntop_get_active_flows_stats (vm=0x7fffb4784808) at src/LuaEngineInterface.cpp:3587
#6 0x00005555557677c6 in luaD_precall ()
#7 0x0000555555772f9d in luaV_execute ()
#8 0x0000555555767a9f in luaD_call ()
#9 0x0000555555767af1 in luaD_callnoyield ()
#10 0x0000555555766f12 in luaD_rawrunprotected ()
#11 0x0000555555767deb in luaD_pcall ()
#12 0x00005555557651a4 in lua_pcallk ()
#13 0x00005555556a3809 in __ntop_lua_handlefile (L=0x7fffb4784808, script_path=script_path@entry=0x7fffc67f6cf0 "/usr/share/ntopng/scripts/lua/flows_stats.lua", ex=ex@entry=true) at src/LuaEngine.cpp:337
#14 0x00005555556a66ad in LuaEngine::handle_script_request (this=this@entry=0x7fffb40bcfb0, conn=conn@entry=0x7fffb4000b20, request_info=request_info@entry=0x7fffb4000b20,
script_path=script_path@entry=0x7fffc67f6cf0 "/usr/share/ntopng/scripts/lua/flows_stats.lua", attack_attempt=attack_attempt@entry=0x7fffc67f6a78, user=user@entry=0x7fffc67f6b30 "angelocolucci", group=,
session_csrf=, localuser=true) at src/LuaEngine.cpp:1152
#15 0x000055555562df4f in handle_lua_request (conn=0x7fffb4000b20) at src/HTTPserver.cpp:1316
#16 0x0000555555626682 in handle_request (conn=conn@entry=0x7fffb4000b20) at src/../third-party/mongoose/mongoose.c:4443
#17 0x0000555555628338 in process_new_connection (conn=0x7fffb4000b20) at src/../third-party/mongoose/mongoose.c:5165
#18 worker_thread (thread_func_param=0x555556bfaa40) at src/../third-party/mongoose/mongoose.c:5259
#19 0x00007ffff64d86db in start_thread (arg=0x7fffc67fc700) at pthread_create.c:463
#20 0x00007ffff3daf71f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thanks in advance for your support

[simonemainardi]

are you using custom protocols?

Please type p proto_id inside the gdb (were you have typed bt) and report the output.

[AngeloColucci]

Hi Simone,

are you using custom protocols?

I don't know how I can do that...

Following the print of proto_id field that you required:

(gdb) bt
#0 nDPIStats::incStats (this=this@entry=0x7fffbb7f6650, when=when@entry=0, proto_id=proto_id@entry=3, sent_packets=, sent_bytes=, rcvd_packets=, rcvd_bytes=0) at src/nDPIStats.cpp:267
#1 0x000055555565aaa9 in Flow::sumStats (this=this@entry=0x7ffe9064a570, ndpi_stats=ndpi_stats@entry=0x7fffbb7f6650, status_stats=status_stats@entry=0x7fffbb7f5f10) at src/Flow.cpp:2389
#2 0x00005555556683f5 in flow_sum_stats (flow=0x7ffe9064a570, user_data=, matched=0x7fffbb7f5dc7) at src/NetworkInterface.cpp:4482
#3 0x0000555555639045 in GenericHash::walk (this=0x555559aaa650, begin_slot=0x7fffbb7f5e1c, walk_all=true, walker=0x5555556683c0 <flow_sum_stats(GenericHashEntry*, void*, bool*)>, user_data=0x7fffbb7f5e20) at src/GenericHash.cpp:222
#4 0x000055555566da3a in NetworkInterface::getActiveFlowsStats (this=this@entry=0x55555654b570, ndpi_stats=ndpi_stats@entry=0x7fffbb7f6650, stats=stats@entry=0x7fffbb7f5f10, allowed_hosts=0x7fffbb7f8440, h=h@entry=0x0,
p=p@entry=0x7fffb457fa00) at src/NetworkInterface.cpp:4508
#5 0x000055555568f422 in ntop_get_active_flows_stats (vm=0x7fffb41002d8) at src/LuaEngineInterface.cpp:3587
#6 0x00005555557677c6 in luaD_precall ()
#7 0x0000555555772f9d in luaV_execute ()
#8 0x0000555555767a9f in luaD_call ()
#9 0x0000555555767af1 in luaD_callnoyield ()
#10 0x0000555555766f12 in luaD_rawrunprotected ()
#11 0x0000555555767deb in luaD_pcall ()
#12 0x00005555557651a4 in lua_pcallk ()
#13 0x00005555556a3809 in __ntop_lua_handlefile (L=0x7fffb41002d8, script_path=script_path@entry=0x7fffbb7f8cf0 "/usr/share/ntopng/scripts/lua/flows_stats.lua", ex=ex@entry=true) at src/LuaEngine.cpp:337
#14 0x00005555556a66ad in LuaEngine::handle_script_request (this=this@entry=0x7fffb40b7f40, conn=conn@entry=0x7fffb4000b20, request_info=request_info@entry=0x7fffb4000b20,
script_path=script_path@entry=0x7fffbb7f8cf0 "/usr/share/ntopng/scripts/lua/flows_stats.lua", attack_attempt=attack_attempt@entry=0x7fffbb7f8a78, user=user@entry=0x7fffbb7f8b30 "angelocolucci", group=,
session_csrf=, localuser=true) at src/LuaEngine.cpp:1152
#15 0x000055555562df4f in handle_lua_request (conn=0x7fffb4000b20) at src/HTTPserver.cpp:1316
#16 0x0000555555626682 in handle_request (conn=conn@entry=0x7fffb4000b20) at src/../third-party/mongoose/mongoose.c:4443
#17 0x0000555555628338 in process_new_connection (conn=0x7fffb4000b20) at src/../third-party/mongoose/mongoose.c:5165
#18 worker_thread (thread_func_param=0x555556a90900) at src/../third-party/mongoose/mongoose.c:5259
#19 0x00007ffff64d86db in start_thread (arg=0x7fffbb7fe700) at pthread_create.c:463
#20 0x00007ffff3daf71f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) p proto_id
$1 = 3