ATTN: parse/bonds: handle same primary in multiple bonds

[daniloegea]

Error out if an interface is declared as primary of multiple bonds. Besides being wrong it's causing a memory leak.

Description

Found with https://github.com/daniloegea/netplan-fuzz

Test case:

network:
  version: 2
  ethernets:
    eno1: {}
  bonds:
    bond0:
      parameters:
        primary: eno1
    bond1:
      parameters:
        primary: eno1

Result

$ ./build/src/generate --root-dir /tmp/fakeroot

=================================================================
==1732948==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 5 byte(s) in 1 object(s) allocated from:
    #0 0x711093a8bb27 in malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x711093794ed9 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x62ed9) (BuildId: ab12e476c12cb3b1fbdd6b86b800846e3dd61000)
    #2 0x7110937aa8a8 in g_strdup (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x788a8) (BuildId: ab12e476c12cb3b1fbdd6b86b800846e3dd61000)
    #3 0x7110939154b9 in g_strdup_inline /usr/include/glib-2.0/glib/gstrfuncs.h:321
    #4 0x7110939154b9 in handle_bond_primary_member ../src/parse.c:2316
    #5 0x711093906547 in process_mapping ../src/parse.c:316
    #6 0x711093915fef in handle_bonding ../src/parse.c:2417
    #7 0x711093906336 in process_mapping ../src/parse.c:310
    #8 0x71109391b5b7 in handle_network_type ../src/parse.c:3302
    #9 0x711093906336 in process_mapping ../src/parse.c:310
    #10 0x7110939063bf in process_mapping ../src/parse.c:312
    #11 0x71109391c4c0 in process_document ../src/parse.c:3446
    #12 0x71109391cb46 in _netplan_parser_load_single_file ../src/parse.c:3504
    #13 0x71109391cebc in netplan_parser_load_yaml ../src/parse.c:3543
    #14 0x7110939356a0 in netplan_parser_load_yaml_hierarchy ../src/util.c:661
    #15 0x5a1f00e1f5ec in main ../src/generate.c:252
    #16 0x7110933131c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #17 0x71109331328a in __libc_start_main_impl ../csu/libc-start.c:360
    #18 0x5a1f00e1d984 in _start (/workspace/netplan-daniloegea/build/src/generate+0x4984) (BuildId: f5aec88fce01a307e0e73c220482bbfa56019c2f)

SUMMARY: AddressSanitizer: 5 byte(s) leaked in 1 allocation(s).

Checklist

• Runs make check successfully.
• Retains 100% code coverage (make check-coverage).
• New/changed keys in YAML format are documented.
• (Optional) Adds example YAML for new feature.
• (Optional) Closes an open bug in Launchpad.

[slyon]

LGTM overall!

This makes parsing stricter, so we need to be very careful with backports/SRUs. Please prefix the commit message with "ATTN: ..." so that this is more obvious for future backporting work.

[daniloegea]

Thanks for the suggestions, Lukas. I added a new commit with my changes to make it easier to review. But they should probably be squashed for merge.