====================================================== WARNING: possible circular locking dependency detected 5.15.158-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor157/3509 is trying to acquire lock: ffff8880237a65d8 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 but task is already holding lock: ffff8880b9b35bb8 (lock#8){+.+.}-{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#8){+.+.}-{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_prog_ec3b2eefa702d8d3+0x3a/0x7cc 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_da8cbe553dc44a71+0x1a/0xfb4 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 __put_user_nocheck_4+0x3/0x11 schedule_tail+0x92/0xb0 kernel/sched/core.c:4970 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:285 other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#8 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#8); lock(&rq->__lock); lock(lock#8); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by syz-executor157/3509: #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1476 [inline] #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x740 arch/x86/mm/fault.c:1532 #1: ffff8880b9b35bb8 (lock#8){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 #2: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #3: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #4: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 3509 Comm: syz-executor157 Not tainted 5.15.158-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+0x1e3/0x2d0 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_da8cbe553dc44a71+0x1a/0xfb4 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:__put_user_nocheck_4+0x3/0x11 Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 0f 1f 44 00 00 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f RSP: 0018:ffffc90002d37f28 EFLAGS: 00050297 RAX: 0000000000000db5 RBX: 00007fffffffeffd RCX: 0000555556914650 RDX: 0000000000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f600 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1bc8c56 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807993c220 R13: 0000000000000000 R14: ffff88807993bb80 R15: dffffc0000000000 schedule_tail+0x92/0xb0 kernel/sched/core.c:4970 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:285 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 39 d9 cmp %rbx,%rcx 5: 73 54 jae 0x5b 7: 0f 01 cb stac a: 66 89 01 mov %ax,(%rcx) d: 31 c9 xor %ecx,%ecx f: 0f 01 ca clac 12: c3 ret 13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 18: 48 bb fd ef ff ff ff movabs $0x7fffffffeffd,%rbx 1f: 7f 00 00 22: 48 39 d9 cmp %rbx,%rcx 25: 73 34 jae 0x5b 27: 0f 01 cb stac * 2a: 89 01 mov %eax,(%rcx) <-- trapping instruction 2c: 31 c9 xor %ecx,%ecx 2e: 0f 01 ca clac 31: c3 ret 32: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 38: 48 rex.W 39: bb f9 ef ff ff mov $0xffffeff9,%ebx 3e: ff (bad) 3f: 7f .byte 0x7f