====================================================== WARNING: possible circular locking dependency detected 5.15.160-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/5961 is trying to acquire lock: ffff88801b081bd8 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 but task is already holding lock: ffff8880b9a35bb8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (lock#10){+.+.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x29/0x170 include/linux/local_lock_internal.h:29 __mmap_lock_do_trace_acquire_returned+0x7c/0x340 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:137 [inline] stack_map_get_build_id_offset+0x612/0x930 kernel/bpf/stackmap.c:185 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:496 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1490 [inline] bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1480 bpf_dispatcher_xdp+0x4a2/0x1000 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x748/0xa30 context_switch kernel/sched/core.c:5016 [inline] __schedule+0x1167/0x45b0 kernel/sched/core.c:6376 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:403 [inline] __text_poke+0x871/0x9e0 arch/x86/kernel/alternative.c:1154 text_poke arch/x86/kernel/alternative.c:1178 [inline] text_poke_bp_batch+0x14c/0x930 arch/x86/kernel/alternative.c:1404 text_poke_flush arch/x86/kernel/alternative.c:1598 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1605 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 tracepoint_add_func+0x947/0x9d0 kernel/tracepoint.c:361 tracepoint_probe_register_prio_may_exist+0x11e/0x190 kernel/tracepoint.c:482 bpf_raw_tracepoint_open+0x65a/0x750 kernel/bpf/syscall.c:3113 __sys_bpf+0x468/0x670 kernel/bpf/syscall.c:4693 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11480 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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+0xae/0x1300 kernel/sched/core.c:4030 signal_wake_up_state kernel/signal.c:770 [inline] signal_wake_up include/linux/sched/signal.h:421 [inline] complete_signal+0x5a0/0x9a0 kernel/signal.c:1062 __send_signal+0xaaf/0xd40 kernel/signal.c:1182 do_notify_parent+0xc1e/0xf00 kernel/signal.c:2113 exit_notify kernel/exit.c:729 [inline] do_exit+0x1464/0x2480 kernel/exit.c:892 do_group_exit+0x144/0x310 kernel/exit.c:994 __do_sys_exit_group kernel/exit.c:1005 [inline] __se_sys_exit_group kernel/exit.c:1003 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0x2b4 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x59c/0x740 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 filldir+0x341/0x720 dir_emit include/linux/fs.h:3674 [inline] proc_fill_cache+0x203/0x440 fs/proc/base.c:2095 proc_ns_dir_readdir+0x364/0x430 fs/proc/namespaces.c:134 iterate_dir+0x224/0x570 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0x1e8/0x4c0 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#10 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#10); lock(&rq->__lock); lock(lock#10); lock(&sighand->siglock); *** DEADLOCK *** 7 locks held by syz-executor.2/5961: #0: ffff88801dbe3770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1088 #1: ffff88807452ec78 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: iterate_dir+0x10a/0x570 fs/readdir.c:55 #2: ffff8880245b6a28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #2: ffff8880245b6a28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] #2: ffff8880245b6a28 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1476 [inline] #2: ffff8880245b6a28 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x740 arch/x86/mm/fault.c:1532 #3: ffff8880b9a35bb8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 #4: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #5: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #6: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 5961 Comm: syz-executor.2 Not tainted 5.15.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0x2b4 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x59c/0x740 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0010:filldir+0x341/0x720 fs/readdir.c:255 Code: 50 02 00 00 0f 01 cb 0f ae e8 48 8b 44 24 30 48 8b 4c 24 18 48 89 41 08 48 8b 44 24 10 48 8b 4c 24 60 48 89 08 48 8b 4c 24 20 <66> 89 48 10 48 63 d1 8b 4c 24 3c 88 4c 10 ff 48 89 54 24 30 49 63 RSP: 0018:ffffc900030c7b00 EFLAGS: 00050283 RAX: 0000000020001ff0 RBX: 0000000020002008 RCX: 0000000000000018 RDX: ffffc90004e41000 RSI: 0000000020002008 RDI: 00007ffffffff000 RBP: 0000000020002008 R08: ffffffff81dad2cf R09: ffffed10032a03b9 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8b798840 R13: ffffc900030c7e70 R14: 0000000000000003 R15: 0000000020001fd8 dir_emit include/linux/fs.h:3674 [inline] proc_fill_cache+0x203/0x440 fs/proc/base.c:2095 proc_ns_dir_readdir+0x364/0x430 fs/proc/namespaces.c:134 iterate_dir+0x224/0x570 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0x1e8/0x4c0 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f18a4185ea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18a2cff0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f18a42bcf80 RCX: 00007f18a4185ea9 RDX: 00000000000000b8 RSI: 0000000020001fc0 RDI: 0000000000000006 RBP: 00007f18a41f4ff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f18a42bcf80 R15: 00007ffff7978a88 ---------------- Code disassembly (best guess): 0: 50 push %rax 1: 02 00 add (%rax),%al 3: 00 0f add %cl,(%rdi) 5: 01 cb add %ecx,%ebx 7: 0f ae e8 lfence a: 48 8b 44 24 30 mov 0x30(%rsp),%rax f: 48 8b 4c 24 18 mov 0x18(%rsp),%rcx 14: 48 89 41 08 mov %rax,0x8(%rcx) 18: 48 8b 44 24 10 mov 0x10(%rsp),%rax 1d: 48 8b 4c 24 60 mov 0x60(%rsp),%rcx 22: 48 89 08 mov %rcx,(%rax) 25: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx * 2a: 66 89 48 10 mov %cx,0x10(%rax) <-- trapping instruction 2e: 48 63 d1 movslq %ecx,%rdx 31: 8b 4c 24 3c mov 0x3c(%rsp),%ecx 35: 88 4c 10 ff mov %cl,-0x1(%rax,%rdx,1) 39: 48 89 54 24 30 mov %rdx,0x30(%rsp) 3e: 49 rex.WB 3f: 63 .byte 0x63