[syzbot] [bpf?] UBSAN: array-index-out-of-bounds in print_bpf_insn (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c93cbdb13f99 selftests/bpf: Add ksock test for async callb..
git tree: bpf-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=104b9279580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2ca5f2f2c4197664
dashboard link: https://syzkaller.appspot.com/bug?extid=3544d9b2a9206be8ba37
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a1aa25580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15019a79580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1714feee6e8f/disk-c93cbdb1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/74187e85e93c/vmlinux-c93cbdb1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b18812cc3696/bzImage-c93cbdb1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3544d9...@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in kernel/bpf/disasm.c:306:6
index 3 is out of range for type 'const char *const[3]'
CPU: 0 UID: 0 PID: 5622 Comm: syz-executor350 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
__ubsan_handle_out_of_bounds+0xe8/0xf0 lib/ubsan.c:455
print_bpf_insn+0x21f1/0x2910 kernel/bpf/disasm.c:306
format_disasm_line kernel/bpf/diagnostics.c:633 [inline]
diag_print_insn_context+0x433/0xd00 kernel/bpf/diagnostics.c:783
bpf_diag_source+0x66a/0x1950 kernel/bpf/diagnostics.c:-1
bpf_diag_program_structure+0x31c/0x430 kernel/bpf/diagnostics.c:1211
check_subprogs+0x66b/0x740 kernel/bpf/verifier.c:3049
bpf_check+0x17ba/0x2e10 kernel/bpf/verifier.c:21099
bpf_prog_load+0x14d6/0x1c20 kernel/bpf/syscall.c:3133
__sys_bpf+0xd0d/0xd90 kernel/bpf/syscall.c:6367
__do_sys_bpf kernel/bpf/syscall.c:6486 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6483 [inline]
__x64_sys_bpf+0xba/0xd0 kernel/bpf/syscall.c:6483
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe861ccec79
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8118b7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffe8118b8f8 RCX: 00007fe861ccec79
RDX: 0000000000000094 RSI: 0000200000000180 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8118b8e8
R13: 0000000000000002 R14: 00007fe861d5fca0 R15: 0000000000000002
</TASK>
---[ end trace ]---


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