============================================ WARNING: possible recursive locking detected 6.0.0-syzkaller-05118-g833477fce7a1 #0 Not tainted -------------------------------------------- syz-executor.3/13950 is trying to acquire lock: ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 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.3/13950: #0: ffffffff8bf83940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2244 [inline] #0: ffffffff8bf83940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xb9/0x3d0 kernel/trace/bpf_trace.c:2288 #1: ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #1: ffffffff8c00b9d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 #2: ffffffff8bf83940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2244 [inline] #2: ffffffff8bf83940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xb9/0x3d0 kernel/trace/bpf_trace.c:2288 stack backtrace: CPU: 0 PID: 13950 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-05118-g833477fce7a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 ___bpf_prog_run+0x369d/0x7960 kernel/bpf/core.c:1818 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2041 bpf_dispatcher_nop_func include/linux/bpf.h:963 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2249 [inline] bpf_trace_run2+0x14d/0x3d0 kernel/trace/bpf_trace.c:2288 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0xda/0x1b0 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x103/0xb50 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 ___bpf_prog_run+0x369d/0x7960 kernel/bpf/core.c:1818 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2041 bpf_dispatcher_nop_func include/linux/bpf.h:963 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2249 [inline] bpf_trace_run2+0x14d/0x3d0 kernel/trace/bpf_trace.c:2288 __traceiter_sys_exit+0x29/0x40 include/trace/events/syscalls.h:44 trace_sys_exit include/trace/events/syscalls.h:44 [inline] syscall_exit_work kernel/entry/common.c:245 [inline] syscall_exit_to_user_mode_prepare+0x1d9/0x280 kernel/entry/common.c:276 __syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline] syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f083b88a5a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f083ca00218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f083b9abf88 RCX: 00007f083b88a5a9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f083b9abf88 RBP: 00007f083b9abf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f083b9abf8c R13: 00007ffe133b7a7f R14: 00007f083ca00300 R15: 0000000000022000