=====================================================
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_run32+0xb2/0xe0 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 include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run5+0x16f/0x350 kernel/trace/bpf_trace.c:2423
 __bpf_trace_signal_generate+0x45/0x60 include/trace/events/signal.h:50
 trace_signal_generate include/trace/events/signal.h:50 [inline]
 __send_signal_locked+0x1157/0x1200 kernel/signal.c:1187
 send_signal_locked+0x761/0xa50 kernel/signal.c:1248
 do_send_sig_info+0x19b/0x240 kernel/signal.c:1301
 group_send_sig_info+0x10c/0x160 kernel/signal.c:1453
 bpf_send_signal_common+0x386/0x410 kernel/trace/bpf_trace.c:881
 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline]
 bpf_send_signal+0x32/0x50 kernel/trace/bpf_trace.c:884
 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
 __bpf_prog_run32+0xb2/0xe0 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 include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run2+0x116/0x300 kernel/trace/bpf_trace.c:2420
 __bpf_trace_kfree+0x29/0x40 include/trace/events/kmem.h:94
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0x69e/0xa60 mm/slub.c:4450
 kvfree+0x69/0x80 mm/util.c:680
 vfree+0x821/0x8c0 mm/vmalloc.c:3344
 xt_compat_flush_offsets+0xd9/0x170 net/netfilter/x_tables.c:691
 get_info net/ipv4/netfilter/ip_tables.c:972 [inline]
 do_ipt_get_ctl+0x195c/0x20a0 net/ipv4/netfilter/ip_tables.c:1659
 nf_getsockopt+0x429/0x480 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x2ba/0x410 net/ipv4/ip_sockglue.c:1777
 tcp_getsockopt+0x15c/0x1a0 net/ipv4/tcp.c:4375
 sock_common_getsockopt+0xa1/0xe0 net/core/sock.c:3700
 do_sock_getsockopt+0x544/0xa00 net/socket.c:2373
 __sys_getsockopt+0x3ca/0x540 net/socket.c:2402
 __do_compat_sys_socketcall net/compat.c:494 [inline]
 __se_compat_sys_socketcall+0x3ff/0x1a20 net/compat.c:423
 __ia32_compat_sys_socketcall+0x6b/0xa0 net/compat.c:423
 ia32_sys_call+0x1bce/0x40a0 arch/x86/include/generated/asm/syscalls_32.h:103
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb4/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Local variable stack created at:
 __bpf_prog_run32+0x43/0xe0 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 include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run5+0x16f/0x350 kernel/trace/bpf_trace.c:2423

CPU: 0 PID: 5376 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-02339-g101b7a97143a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
=====================================================