====================================================== WARNING: possible circular locking dependency detected 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Not tainted ------------------------------------------------------ klogd/4524 is trying to acquire lock: ffff8880b9338ac0 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9338ac0 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x790 mm/mmap_lock.c:237 but task is already holding lock: ffff8880b933ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1406 [inline] rq_lock kernel/sched/sched.h:1702 [inline] task_fork_fair+0x73/0x250 kernel/sched/fair.c:12710 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4844 copy_process+0x439b/0x8f10 kernel/fork.c:2499 kernel_clone+0xfd/0x980 kernel/fork.c:2797 user_mode_thread+0xb4/0xf0 kernel/fork.c:2875 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3df/0x4c0 init/main.c:1103 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #2 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4262 signal_wake_up_state+0x79/0x120 kernel/signal.c:773 signal_wake_up include/linux/sched/signal.h:448 [inline] complete_signal+0x465/0xc10 kernel/signal.c:1065 __send_signal_locked+0x509/0x11c0 kernel/signal.c:1185 do_notify_parent+0xeb4/0x1040 kernel/signal.c:2143 exit_notify kernel/exit.c:753 [inline] do_exit+0x1369/0x2c10 kernel/exit.c:897 do_group_exit+0xd3/0x2a0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [inline] __se_sys_exit_group kernel/exit.c:1035 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1035 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&sighand->siglock){....}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1453 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2446 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x456/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_lock include/linux/mmap_lock.h:145 [inline] process_vm_rw_single_vec mm/process_vm_access.c:105 [inline] process_vm_rw_core.constprop.0+0x7d7/0xa10 mm/process_vm_access.c:216 process_vm_rw+0x301/0x360 mm/process_vm_access.c:284 __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline] __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline] __x64_sys_process_vm_readv+0xe2/0x1c0 mm/process_vm_access.c:292 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (lock#9){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x5d9/0x7c0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1984 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_tlb_flush+0xd2/0x110 include/trace/events/tlb.h:38 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x68b/0xbc0 arch/x86/mm/tlb.c:642 context_switch kernel/sched/core.c:5392 [inline] __schedule+0xd2b/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 syslog_print+0x214/0x5d0 kernel/printk/printk.c:1582 do_syslog+0x3be/0x6a0 kernel/printk/printk.c:1734 __do_sys_syslog kernel/printk/printk.c:1826 [inline] __se_sys_syslog kernel/printk/printk.c:1824 [inline] __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1824 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: lock#9 --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(lock#9); *** DEADLOCK *** 3 locks held by klogd/4524: #0: ffff8880b933ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 #2: ffff888015477398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #2: ffff888015477398 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x1e8/0x7c0 kernel/bpf/stackmap.c:141 stack backtrace: CPU: 1 PID: 4524 Comm: klogd Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x5d9/0x7c0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1984 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_tlb_flush+0xd2/0x110 include/trace/events/tlb.h:38 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x68b/0xbc0 arch/x86/mm/tlb.c:642 context_switch kernel/sched/core.c:5392 [inline] __schedule+0xd2b/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 syslog_print+0x214/0x5d0 kernel/printk/printk.c:1582 do_syslog+0x3be/0x6a0 kernel/printk/printk.c:1734 __do_sys_syslog kernel/printk/printk.c:1826 [inline] __se_sys_syslog kernel/printk/printk.c:1824 [inline] __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1824 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f70c5278fa7 Code: Unable to access opcode bytes at 0x7f70c5278f7d. RSP: 002b:00007ffcd7812ff8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f70c54174a0 RCX: 00007f70c5278fa7 RDX: 00000000000003ff RSI: 00007f70c54174a0 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000003 R09: 7abf98d885e43ab6 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f70c54174a0 R13: 00007f70c5407212 R14: 00007f70c5417666 R15: 00007f70c5417666