============================================ WARNING: possible recursive locking detected 6.1.0-rc4-syzkaller-00962-g2cf7e87fc459 #0 Not tainted -------------------------------------------- syz-executor.5/15461 is trying to acquire lock: ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:377 but task is already holding lock: ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:377 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 5 locks held by syz-executor.5/15461: #0: ffffffff8d8561b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:1075 #1: ffff888049c87688 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xbe/0xc50 net/netlink/af_netlink.c:2234 #2: ffffffff8bf88c80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] #2: ffffffff8bf88c80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run1+0xb1/0x3d0 kernel/trace/bpf_trace.c:2301 #3: ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] #3: ffffffff8c011a58 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:377 #4: ffffffff8bf88c80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] #4: ffffffff8bf88c80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xb9/0x3d0 kernel/trace/bpf_trace.c:2302 stack backtrace: CPU: 1 PID: 15461 Comm: syz-executor.5 Not tainted 6.1.0-rc4-syzkaller-00962-g2cf7e87fc459 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 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:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 __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:391 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:960 [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:2263 [inline] bpf_trace_run2+0x14d/0x3d0 kernel/trace/bpf_trace.c:2302 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0x143/0x240 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:391 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:960 [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:2263 [inline] bpf_trace_run1+0x145/0x3d0 kernel/trace/bpf_trace.c:2301 __bpf_trace_rcu_utilization+0x81/0xb0 include/trace/events/rcu.h:27 __traceiter_rcu_utilization+0x4e/0x90 include/trace/events/rcu.h:27 trace_rcu_utilization+0x13e/0x230 include/trace/events/rcu.h:27 rcu_note_context_switch+0x6f/0x1850 kernel/rcu/tree_plugin.h:316 __schedule+0x238/0x53f0 kernel/sched/core.c:6403 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6672 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __mutex_lock_common kernel/locking/mutex.c:728 [inline] __mutex_lock+0xff7/0x1350 kernel/locking/mutex.c:747 netlink_dump+0xbe/0xc50 net/netlink/af_netlink.c:2234 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2391 genl_family_rcv_msg_dumpit+0x1b5/0x310 net/netlink/genetlink.c:918 genl_family_rcv_msg net/netlink/genetlink.c:1045 [inline] genl_rcv_msg+0x415/0x7d0 net/netlink/genetlink.c:1065 netlink_rcv_skb+0x161/0x440 net/netlink/af_netlink.c:2564 genl_rcv+0x24/0x40 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1932 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f25ddc8b639 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:00007f25de9b7168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f25dddabf80 RCX: 00007f25ddc8b639 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007f25ddce67e1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd0343edcf R14: 00007f25de9b7300 R15: 0000000000022000