=====================================================
BUG: KMSAN: uninit-value in strnchr+0x90/0xd0 lib/string.c:387
 strnchr+0x90/0xd0 lib/string.c:387
 bpf_bprintf_prepare+0x1c2/0x23c0 kernel/bpf/helpers.c:829
 ____bpf_trace_printk kernel/trace/bpf_trace.c:385 [inline]
 bpf_trace_printk+0xec/0x3e0 kernel/trace/bpf_trace.c:375
 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
 __bpf_prog_run160+0xb5/0xe0 kernel/bpf/core.c:2236
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run_xdp include/net/xdp.h:514 [inline]
 bpf_test_run+0x43e/0xc30 net/bpf/test_run.c:423
 bpf_prog_test_run_xdp+0xeaa/0x1a40 net/bpf/test_run.c:1269
 bpf_prog_test_run+0x6b7/0xad0 kernel/bpf/syscall.c:4269
 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5678
 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
 __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765
 x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable stack created at:
 __bpf_prog_run160+0x45/0xe0 kernel/bpf/core.c:2236
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run_xdp include/net/xdp.h:514 [inline]
 bpf_test_run+0x43e/0xc30 net/bpf/test_run.c:423

CPU: 1 PID: 7008 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00031-g71b1543c83d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================