ahocorasick: fix mem leaked AC_NODE_T object (#2258)

[mmaatuq]

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• I have read the contributing guidelines at https://github.com/ntop/nDPI/blob/dev/CONTRIBUTING.md
• I have updated the documentation (in doc/) to reflect the changes made (if applicable)

Link to the related issue:

Describe changes:

skipping node at depth = AC_PATTRN_MAX_LENGTH inside ac_automata_walk() caused this leak, as one of the added patterns has len = AC_PATTRN_MAX_LENGTH (not including the null char), this change avoid this
Fixes:
==3162838==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 40 byte(s) in 1 object(s) allocated from:
0 0x50f072 in malloc (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x50f072) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
1 0x552f20 in malloc_wrapper /root/workspace/ntop/nDPI/fuzz/fuzz_common_code.c:16:31
2 0x68a0a5 in ndpi_malloc /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:60:25
3 0x68a0fd in ndpi_calloc /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:67:13
4 0x9c5b3a in node_create /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:802:25
5 0x9c760e in node_create_next /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:1007:10
6 0x9c6653 in ac_automata_add /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:255:19
7 0x5861d0 in ndpi_add_host_risk_mask /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4573:8
8 0x590c0e in ndpi_handle_rule /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4655:11
9 0x58ffd5 in load_protocols_file_fd /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:5446:8
10 0x552c60 in LLVMFuzzerTestOneInput /root/workspace/ntop/nDPI/fuzz/fuzz_filecfg_protocols.c:21:3
11 0x44be94 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x44be94) (Build
Id: 36867732af52eb22433f5e34fe5422a8af281aa6)
12 0x4334f7 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4334f7) (BuildId: 3
6867732af52eb22433f5e34fe5422a8af281aa6)
13 0x4391e1 in fuzzer::FuzzerDriver(int*, char***, int ()(unsigned char const, unsigned long)) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4
391e1) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
14 0x467323 in main (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x467323) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
15 0x7fce386e97e4 in __libc_start_main (/lib64/libc.so.6+0x3a7e4) (BuildId: b81415c1738806b536fb1599d7af2d15bf6a86b7)

Indirect leak of 328 byte(s) in 1 object(s) allocated from:
0 0x50f072 in malloc (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x50f072) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
1 0x552f20 in malloc_wrapper /root/workspace/ntop/nDPI/fuzz/fuzz_common_code.c:16:31
2 0x68a0a5 in ndpi_malloc /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:60:25
3 0x68a0fd in ndpi_calloc /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:67:13
4 0x9da348 in node_resize_mp /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:1027:13
5 0x9c79d7 in node_register_matchstr /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:1055:30
6 0x9c6f21 in ac_automata_add /root/workspace/ntop/nDPI/src/lib/third_party/src/ahocorasick.c:280:6
7 0x5861d0 in ndpi_add_host_risk_mask /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4573:8
8 0x590c0e in ndpi_handle_rule /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4655:11
9 0x58ffd5 in load_protocols_file_fd /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:5446:8
10 0x552c60 in LLVMFuzzerTestOneInput /root/workspace/ntop/nDPI/fuzz/fuzz_filecfg_protocols.c:21:3
11 0x44be94 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x44be94) (Build
Id: 36867732af52eb22433f5e34fe5422a8af281aa6)
12 0x4334f7 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4334f7) (BuildId: 3
6867732af52eb22433f5e34fe5422a8af281aa6)
13 0x4391e1 in fuzzer::FuzzerDriver(int*, char***, int ()(unsigned char const, unsigned long)) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4
391e1) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
14 0x467323 in main (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x467323) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
15 0x7fce386e97e4 in __libc_start_main (/lib64/libc.so.6+0x3a7e4) (BuildId: b81415c1738806b536fb1599d7af2d15bf6a86b7)

Indirect leak of 257 byte(s) in 1 object(s) allocated from:
0 0x50f072 in malloc (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x50f072) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
1 0x552f20 in malloc_wrapper /root/workspace/ntop/nDPI/fuzz/fuzz_common_code.c:16:31
2 0x68a0a5 in ndpi_malloc /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:60:25
3 0x68a390 in ndpi_strdup /root/workspace/ntop/nDPI/src/lib/ndpi_memory.c:113:13
4 0x585e2b in ndpi_add_host_risk_mask /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4558:14
5 0x590c0e in ndpi_handle_rule /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:4655:11
6 0x58ffd5 in load_protocols_file_fd /root/workspace/ntop/nDPI/src/lib/ndpi_main.c:5446:8
7 0x552c60 in LLVMFuzzerTestOneInput /root/workspace/ntop/nDPI/fuzz/fuzz_filecfg_protocols.c:21:3
8 0x44be94 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x44be94) (BuildI
d: 36867732af52eb22433f5e34fe5422a8af281aa6)
9 0x4334f7 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4334f7) (BuildId: 36
867732af52eb22433f5e34fe5422a8af281aa6)
10 0x4391e1 in fuzzer::FuzzerDriver(int*, char***, int ()(unsigned char const, unsigned long)) (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x4
391e1) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
11 0x467323 in main (/media/veracrypt1/work-space/ntop/nDPI/fuzz/fuzz_filecfg_protocols+0x467323) (BuildId: 36867732af52eb22433f5e34fe5422a8af281aa6)
12 0x7fce386e97e4 in __libc_start_main (/lib64/libc.so.6+0x3a7e4) (BuildId: b81415c1738806b536fb1599d7af2d15bf6a86b7)

SUMMARY: AddressSanitizer: 625 byte(s) leaked in 3 allocation(s).

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[IvanNardi]

@pavlinux , @vel21ripn what do you think?

[vel21ripn]

It's very good that you were able to find and correct the error.

[IvanNardi]

I don't have the expertise to evaluate this change, but I trust @vel21ripn comment.
Let's see what happens in the next days on oss-fuzz...
@mmaatuq, thank you very much for working on that long-standing issue

[mmaatuq]

I don't have the expertise to evaluate this change, but I trust @vel21ripn comment. Let's see what happens in the next days on oss-fuzz... @mmaatuq, thank you very much for working on that long-standing issue

Hopefully this is the right solution for it, as I was thinking of another one , patterns length that are added should be < AC_PATTRN_MAX_LENGTH without equal.

thank you too.