====================================================== WARNING: possible circular locking dependency detected 6.1.91-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/7574 is trying to acquire lock: ffff888059356f18 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333 but task is already holding lock: ffff8880b983aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1354 [inline] rq_lock kernel/sched/sched.h:1644 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686 copy_process+0x2442/0x4060 kernel/fork.c:2384 kernel_clone+0x222/0x920 kernel/fork.c:2682 user_mode_thread+0x12e/0x190 kernel/fork.c:2758 rest_init+0x23/0x300 init/main.c:699 start_kernel+0x0/0x53f init/main.c:894 start_kernel+0x496/0x53f init/main.c:1141 secondary_startup_64_no_verify+0xcf/0xdb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112 signal_wake_up_state kernel/signal.c:780 [inline] signal_wake_up include/linux/sched/signal.h:457 [inline] complete_signal+0x796/0xbd0 kernel/signal.c:1074 __send_signal_locked+0xb1a/0xdc0 kernel/signal.c:1194 do_notify_parent+0xe2b/0x1100 kernel/signal.c:2120 exit_notify kernel/exit.c:744 [inline] do_exit+0x172e/0x26a0 kernel/exit.c:889 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 __do_sys_exit_group kernel/exit.c:1030 [inline] __se_sys_exit_group kernel/exit.c:1028 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333 force_sig_fault_to_task kernel/signal.c:1724 [inline] force_sig_fault+0x127/0x1d0 kernel/signal.c:1730 __bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828 handle_page_fault arch/x86/mm/fault.c:1460 [inline] exc_page_fault+0x3bf/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 copy_from_kernel_nofault+0x297/0x2c0 bpf_probe_read_kernel_common kernel/trace/bpf_trace.c:230 [inline] ____bpf_probe_read_compat kernel/trace/bpf_trace.c:294 [inline] bpf_probe_read_compat+0x10a/0x180 kernel/trace/bpf_trace.c:287 bpf_prog_04da3e87137f0056+0x3a/0x3c bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2116/0x4550 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658 __sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:203 __x64_sys_gettimeofday+0x17/0x60 kernel/time/time.c:140 emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1462 [inline] exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 _end+0x6d3da000/0x0 other info that might help us debug this: Chain exists of: &sighand->siglock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(&sighand->siglock); *** DEADLOCK *** 2 locks held by syz-executor.0/7574: #0: ffff8880b983aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314 stack backtrace: CPU: 0 PID: 7574 Comm: syz-executor.0 Not tainted 6.1.91-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 force_sig_info_to_task+0x69/0x470 kernel/signal.c:1333 force_sig_fault_to_task kernel/signal.c:1724 [inline] force_sig_fault+0x127/0x1d0 kernel/signal.c:1730 __bad_area_nosemaphore+0x126/0x730 arch/x86/mm/fault.c:828 handle_page_fault arch/x86/mm/fault.c:1460 [inline] exc_page_fault+0x3bf/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:copy_from_kernel_nofault+0x297/0x2c0 Code: 2a 28 00 eb b6 44 89 f9 80 e1 07 38 c1 7c 8a 4c 89 ff e8 5c 2a 28 00 eb 80 4c 89 f5 e8 b2 aa d0 ff eb 0f e8 ab aa d0 ff eb 08 <4c> 89 f5 e8 a1 aa d0 ff 48 c7 c3 f2 ff ff ff 49 89 ee 48 8b 0c 24 RSP: 0000:ffffc900149c7948 EFLAGS: 00010057 RAX: 0000000000000002 RBX: ffffc900149c79c8 RCX: ffff8880795bbb80 RDX: ffffc90004a99000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: 0000000000000002 R08: ffffffff81b9e177 R09: ffffed100f2b7771 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffffffffffe8 R13: 0000000000000000 R14: ffff8880795bd2f0 R15: ffffc900149c79ca bpf_probe_read_kernel_common kernel/trace/bpf_trace.c:230 [inline] ____bpf_probe_read_compat kernel/trace/bpf_trace.c:294 [inline] bpf_probe_read_compat+0x10a/0x180 kernel/trace/bpf_trace.c:287 bpf_prog_04da3e87137f0056+0x3a/0x3c bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2116/0x4550 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:206 Code: 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 58 fd e8 0c 48 89 de 5b e9 97 a8 56 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0d e4 e1 77 7e 65 8b 15 e5 e1 77 7e f7 c2 00 01 ff 00 74 RSP: 0000:ffffc900149c7e40 EFLAGS: 00000287 RAX: ffffffff817861b7 RBX: ffffc900149c7f58 RCX: 0000000000040000 RDX: ffffc90004a99000 RSI: 0000000000001bab RDI: ffffc900149c7f58 RBP: dffffc0000000000 R08: 0000000000000005 R09: ffffffff81008553 R10: 0000000000000003 R11: ffff8880795bbb80 R12: 1ffff1100f2b7a8a R13: ffff8880795bd450 R14: 0000000000000000 R15: dffffc0000000000 __x64_sys_gettimeofday+0x17/0x60 kernel/time/time.c:140 emulate_vsyscall+0xc5c/0x1240 arch/x86/entry/vsyscall/vsyscall_64.c:247 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1462 [inline] exc_page_fault+0x154/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:_end+0x6d3da000/0x0 Code: Unable to access opcode bytes at 0xffffffffff5fffd6. RSP: 002b:00007f9e8d83bb38 EFLAGS: 00010246 RAX: ffffffffffffffda RBX: 00007f9e8cbabf80 RCX: 00007f9e8ca7cee9 RDX: 00007f9e8d83bb40 RSI: 00007f9e8d83bc70 RDI: 0000000000000019 RBP: 00007f9e8cac949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9e8cbabf80 R15: 00007ffcee80a4b8 ---------------- Code disassembly (best guess): 0: 2a 28 sub (%rax),%ch 2: 00 eb add %ch,%bl 4: b6 44 mov $0x44,%dh 6: 89 f9 mov %edi,%ecx 8: 80 e1 07 and $0x7,%cl b: 38 c1 cmp %al,%cl d: 7c 8a jl 0xffffff99 f: 4c 89 ff mov %r15,%rdi 12: e8 5c 2a 28 00 call 0x282a73 17: eb 80 jmp 0xffffff99 19: 4c 89 f5 mov %r14,%rbp 1c: e8 b2 aa d0 ff call 0xffd0aad3 21: eb 0f jmp 0x32 23: e8 ab aa d0 ff call 0xffd0aad3 28: eb 08 jmp 0x32 * 2a: 4c 89 f5 mov %r14,%rbp <-- trapping instruction 2d: e8 a1 aa d0 ff call 0xffd0aad3 32: 48 c7 c3 f2 ff ff ff mov $0xfffffffffffffff2,%rbx 39: 49 89 ee mov %rbp,%r14 3c: 48 8b 0c 24 mov (%rsp),%rcx