Subject: [syzbot] WARNING in bpf_verifier_vlog

From: syzbot <[email-masked]>
Date: Thu, 08 Sep 2022 21:19:25 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    7e18e42e4b28 Linux 6.0-rc4
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1551da55080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f4d613baa509128c
dashboard link: https://syzkaller.appspot.com/bug?extid=8b2a08dfbd25fd933d75
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1798cab7080000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ccbdc5080000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/da260c675b46/disk-7e18e42e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/58f7bbbaa6ff/vmlinux-7e18e42e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
verifier log line truncated - local buffer too short
WARNING: CPU: 1 PID: 3604 at kernel/bpf/verifier.c:300 bpf_verifier_vlog+0x267/0x3c0 kernel/bpf/verifier.c:300
Modules linked in:
CPU: 1 PID: 3604 Comm: syz-executor146 Not tainted 6.0.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
RIP: 0010:bpf_verifier_vlog+0x267/0x3c0 kernel/bpf/verifier.c:300
Code: f5 95 3d 0c 31 ff 89 ee e8 06 07 f0 ff 40 84 ed 75 1a e8 7c 0a f0 ff 48 c7 c7 c0 e7 f3 89 c6 05 d4 95 3d 0c 01 e8 fb 4c ae 07 <0f> 0b e8 62 0a f0 ff 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1
RSP: 0018:ffffc900039bf8a0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888017a19210 RCX: 0000000000000000
RDX: ffff888021fb1d80 RSI: ffffffff8161f408 RDI: fffff52000737f06
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffffffff89f5aba0
R13: 00000000000003ff R14: ffff888017a19214 R15: ffff888012705800
FS:  0000555555cba300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020100000 CR3: 000000001bf9e000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 __btf_verifier_log+0xbb/0xf0 kernel/bpf/btf.c:1375
 __btf_verifier_log_type+0x451/0x8f0 kernel/bpf/btf.c:1413
 btf_func_proto_check_meta+0x117/0x160 kernel/bpf/btf.c:3905
 btf_check_meta kernel/bpf/btf.c:4588 [inline]
 btf_check_all_metas+0x3c1/0xa70 kernel/bpf/btf.c:4612
 btf_parse_type_sec kernel/bpf/btf.c:4748 [inline]
 btf_parse kernel/bpf/btf.c:5031 [inline]
 btf_new_fd+0x939/0x1e70 kernel/bpf/btf.c:6710
 bpf_btf_load kernel/bpf/syscall.c:4314 [inline]
 __sys_bpf+0x13bd/0x6130 kernel/bpf/syscall.c:4998
 __do_sys_bpf kernel/bpf/syscall.c:5057 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5055 [inline]
 __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb092221c29
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff5b0a6878 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb092221c29
RDX: 0000000000000020 RSI: 0000000020000240 RDI: 0000000000000012
RBP: 00007fb0921e5dd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb0921e5e60
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

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