BUG: using smp_processor_id() in preemptible [00000000] code: syz.3.4113/17542
caller is debug_smp_processor_id+0x20/0x24 lib/smp_processor_id.c:58
CPU: 1 UID: 0 PID: 17542 Comm: syz.3.4113 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: ARM-Versatile Express
Call trace: 
[<80201998>] (dump_backtrace) from [<80201a8c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:60000013 r6:60000013 r5:82336570 r4:00000000
[<80201a74>] (show_stack) from [<8021ec68>] (__dump_stack lib/dump_stack.c:94 [inline])
[<80201a74>] (show_stack) from [<8021ec68>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120)
[<8021ec0c>] (dump_stack_lvl) from [<8021ec94>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r7:00000001 r6:82345518 r5:81b6ebe0 r4:84929880
[<8021ec7c>] (dump_stack) from [<81b6ebbc>] (check_preemption_disabled+0xfc/0x100 lib/smp_processor_id.c:47)
[<81b6eac0>] (check_preemption_disabled) from [<81b6ebe0>] (debug_smp_processor_id+0x20/0x24 lib/smp_processor_id.c:58)
 r7:81774940 r6:00000377 r5:87100600 r4:828d3b40
[<81b6ebc0>] (debug_smp_processor_id) from [<816ced7c>] (net_dm_packet_trace_kfree_skb_hit+0x68/0x134 net/core/drop_monitor.c:519)
[<816ced14>] (net_dm_packet_trace_kfree_skb_hit) from [<816c02d0>] (__traceiter_kfree_skb+0x50/0x68 include/trace/events/skb.h:24)
 r9:816ced14 r8:00000000 r7:00000002 r6:81774940 r5:8387a900 r4:86910388
[<816c0280>] (__traceiter_kfree_skb) from [<81646140>] (__do_trace_kfree_skb include/trace/events/skb.h:24 [inline])
[<816c0280>] (__traceiter_kfree_skb) from [<81646140>] (trace_kfree_skb include/trace/events/skb.h:24 [inline])
[<816c0280>] (__traceiter_kfree_skb) from [<81646140>] (__sk_skb_reason_drop net/core/skbuff.c:1231 [inline])
[<816c0280>] (__traceiter_kfree_skb) from [<81646140>] (sk_skb_reason_drop+0x140/0x298 net/core/skbuff.c:1249)
 r9:00000000 r8:828cb740 r7:00000000 r6:81774940 r5:00000002 r4:8387a900
[<81646000>] (sk_skb_reason_drop) from [<81774940>] (kfree_skb_reason include/linux/skbuff.h:1323 [inline])
[<81646000>] (sk_skb_reason_drop) from [<81774940>] (kfree_skb include/linux/skbuff.h:1332 [inline])
[<81646000>] (sk_skb_reason_drop) from [<81774940>] (bpf_prog_test_run_skb+0x474/0xcd0 net/bpf/test_run.c:1266)
 r9:00000000 r8:865d5800 r7:00000001 r6:8387a900 r5:00000000 r4:dfd59e98
[<817744cc>] (bpf_prog_test_run_skb) from [<803ebe98>] (bpf_prog_test_run kernel/bpf/syscall.c:4859 [inline])
[<817744cc>] (bpf_prog_test_run_skb) from [<803ebe98>] (__sys_bpf+0x122c/0x219c kernel/bpf/syscall.c:6436)
 r10:84929880 r9:00000050 r8:00000000 r7:00000050 r6:0000000a r5:dfbb5000
 r4:00000000
[<803eac6c>] (__sys_bpf) from [<803ed418>] (__do_sys_bpf kernel/bpf/syscall.c:6537 [inline])
[<803eac6c>] (__sys_bpf) from [<803ed418>] (sys_bpf+0x50/0x6c kernel/bpf/syscall.c:6534)
 r10:00000182 r9:84929880 r8:8020029c r7:00000182 r6:00356310 r5:00000000
 r4:00000000
[<803ed3c8>] (sys_bpf) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdfd59fa8 to 0xdfd59ff0)
9fa0:                   00000000 00000000 0000000a 20000200 00000050 00000000
9fc0: 00000000 00000000 00356310 00000182 003562d8 00000000 00000001 76fa00dc
9fe0: 76f9fe88 76f9fe78 00018fa0 00130a50