====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc7-syzkaller-02062-g83eea61776c9 #0 Not tainted ------------------------------------------------------ syz-executor.0/19173 is trying to acquire lock: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_start_locking+0x83/0x620 mm/mmap_lock.c:230 but task is already holding lock: ffff8880b953e698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1406 [inline] rq_lock_irqsave kernel/sched/sched.h:1685 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1739 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:12005 exit_signals+0x2a1/0x5c0 kernel/signal.c:3016 do_exit+0x6a8/0x27e0 kernel/exit.c:837 __do_sys_exit kernel/exit.c:994 [inline] __se_sys_exit kernel/exit.c:992 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:992 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&sighand->siglock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 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+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 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 0xffffffffa0000965 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+0x334/0x590 kernel/trace/bpf_trace.c:2446 __traceiter_mmap_lock_acquire_returned+0x93/0xf0 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+0x5c8/0x630 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:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5693 do_user_addr_fault arch/x86/mm/fault.c:1354 [inline] handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x1a9/0x8a0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #0 (lock#10){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x620 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x98d/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1984 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1066/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep+0x32b/0x3c0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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#10 --> &sighand->siglock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&sighand->siglock); lock(&rq->__lock); lock(lock#10); *** DEADLOCK *** 2 locks held by syz-executor.0/19173: #0: ffff8880b953e698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 19173 Comm: syz-executor.0 Not tainted 6.9.0-rc7-syzkaller-02062-g83eea61776c9 #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+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x620 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x98d/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1984 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1066/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep+0x32b/0x3c0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f145c6a82f5 Code: Unable to access opcode bytes at 0x7f145c6a82cb. RSP: 002b:00007ffc2fff5e70 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007f145c7abf80 RCX: 00007f145c6a82f5 RDX: 00007ffc2fff5eb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f145c7ad980 R08: 0000000000000000 R09: 00007f145d46f0b0 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000ce1b5 R13: 00007f145c7ac05c R14: 00007f145c7ac050 R15: 0000000000000032