============================================ WARNING: possible recursive locking detected 6.0.0-rc3-syzkaller-00031-gc5e4d5e99162 #0 Not tainted -------------------------------------------- syz-executor.5/25243 is trying to acquire lock: ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(trace_printk_lock); lock(trace_printk_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor.5/25243: #0: ffffffff8cd20860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 #1: ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #1: ffffffff8cd7d4f8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 #2: ffffffff8cd20860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 stack backtrace: CPU: 1 PID: 25243 Comm: syz-executor.5 Not tainted 6.0.0-rc3-syzkaller-00031-gc5e4d5e99162 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain+0x4897/0x6600 kernel/locking/lockdep.c:3816 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5666 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 trace_contention_begin+0x16b/0x190 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x10f/0xc60 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x264/0x360 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 __bpf_trace_sys_exit+0x60/0x70 include/trace/events/syscalls.h:44 trace_sys_exit+0xb2/0xd0 include/trace/events/syscalls.h:44 syscall_exit_work+0x4a/0xe0 kernel/entry/common.c:245 syscall_exit_to_user_mode_prepare+0x6b/0xc0 kernel/entry/common.c:276 __syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline] syscall_exit_to_user_mode+0xa/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6cc4c3cf43 Code: 1f 84 00 00 00 00 00 83 c0 16 83 e0 f7 75 e2 eb 96 66 0f 1f 44 00 00 48 81 c7 e0 02 00 00 be 18 00 00 00 b8 11 01 00 00 0f 05 66 66 2e 0f 1f 84 00 00 00 00 00 90 41 54 55 64 48 8b 14 25 10 RSP: 002b:00007ffcefe42558 EFLAGS: 00000202 ORIG_RAX: 0000000000000111 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6cc4c3cf43 RDX: 0000000000000000 RSI: 0000000000000018 RDI: 0000555556b926e0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000555556b92400 R10: 0000555556b926d0 R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffcefe42640