[syzbot] [bpf?] linux-next boot error: WARNING in register_btf_kfunc_id_set

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 51b70ff55ed8 Add linux-next specific files for 20240201
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17b05288180000
kernel config: https://syzkaller.appspot.com/x/.config?x=88d85200b6a62126
dashboard link: https://syzkaller.appspot.com/bug?extid=0e9c9f96dbdc31a8431b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f2d3a98d07e5/disk-51b70ff5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d525430ddf13/vmlinux-51b70ff5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6d1ec0b50066/bzImage-51b70ff5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0e9c9f...@syzkaller.appspotmail.com

greybus: registered new driver hid
greybus: registered new driver gbphy
gb_gbphy: registered new driver usb
asus_wmi: ASUS WMI generic driver loaded
usbcore: registered new interface driver snd-usb-audio
usbcore: registered new interface driver snd-ua101
usbcore: registered new interface driver snd-usb-usx2y
usbcore: registered new interface driver snd-usb-us122l
usbcore: registered new interface driver snd-usb-caiaq
usbcore: registered new interface driver snd-usb-6fire
usbcore: registered new interface driver snd-usb-hiface
usbcore: registered new interface driver snd-bcd2000
usbcore: registered new interface driver snd_usb_pod
usbcore: registered new interface driver snd_usb_podhd
usbcore: registered new interface driver snd_usb_toneport
usbcore: registered new interface driver snd_usb_variax
drop_monitor: Initializing network drop monitor service
NET: Registered PF_LLC protocol family
GACT probability on
Mirror/redirect action on
Simple TC action Loaded
netem: version 1.3
u32 classifier
Performance counters on
input device check on
Actions configured
nf_conntrack_irc: failed to register helpers
nf_conntrack_sane: failed to register helpers
nf_conntrack_sip: failed to register helpers
xt_time: kernel timezone is -0000
IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
IPVS: Connection hash table configured (size=4096, memory=32Kbytes)
IPVS: ipvs loaded.
IPVS: [rr] scheduler registered.
IPVS: [wrr] scheduler registered.
IPVS: [lc] scheduler registered.
IPVS: [wlc] scheduler registered.
IPVS: [fo] scheduler registered.
IPVS: [ovf] scheduler registered.
IPVS: [lblc] scheduler registered.
IPVS: [lblcr] scheduler registered.
IPVS: [dh] scheduler registered.
IPVS: [sh] scheduler registered.
IPVS: [mh] scheduler registered.
IPVS: [sed] scheduler registered.
IPVS: [nq] scheduler registered.
IPVS: [twos] scheduler registered.
IPVS: [sip] pe registered.
ipip: IPv4 and MPLS over IPv4 tunneling driver
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at kernel/bpf/btf.c:8131 register_btf_kfunc_id_set+0x261/0x290 kernel/bpf/btf.c:8131
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc2-next-20240201-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:register_btf_kfunc_id_set+0x261/0x290 kernel/bpf/btf.c:8131
Code: 16 e8 b3 fb db ff bd 0b 00 00 00 eb 0a e8 a7 fb db ff bd 0d 00 00 00 89 ef 4c 89 f6 5b 41 5e 41 5f 5d eb 45 e8 90 fb db ff 90 <0f> 0b 90 e9 22 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c da fd
RSP: 0000:ffffc90000067940 EFLAGS: 00010293
RAX: ffffffff81b7d510 RBX: 0000000000000000 RCX: ffff888016a98000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81b7d311 R09: 1ffffffff1f0b5bd
R10: dffffc0000000000 R11: fffffbfff1f0b5be R12: 1ffffffff21e0e1d
R13: dffffc0000000000 R14: ffffffff8caa77c0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000df32000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
fou_init+0x50/0x110 net/ipv4/fou_core.c:1239
do_one_initcall+0x238/0x830 init/main.c:1233
do_initcall_level+0x157/0x210 init/main.c:1295
do_initcalls+0x3f/0x80 init/main.c:1311
kernel_init_freeable+0x430/0x5d0 init/main.c:1549
kernel_init+0x1d/0x2b0 init/main.c:1439
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
</TASK>


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[Jiri Olsa]

should be fixed by https://lore.kernel.org/bpf/CAADnVQJT8nOiiX90g3Pm7Ud0...@mail.gmail.com/

jirka

[Stephen Rothwell]

Hi syzbot,

#syz fix: bpf: btf: Add BTF_KFUNCS_START/END macro pair

This is a new version of a commit in linux-next yesterday.

--
Cheers,
Stephen Rothwell