syzbot

======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc5-syzkaller-00169-gdc6be0b73f4f #0 Not tainted
------------------------------------------------------
syz-executor329/5088 is trying to acquire lock:
ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237

but task is already holding lock:
ffff8880b943e798 (&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:

-> #3 (&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:1406 [inline]
       rq_lock kernel/sched/sched.h:1702 [inline]
       task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12710
       sched_cgroup_fork+0x37c/0x410 kernel/sched/core.c:4844
       copy_process+0x2217/0x3dc0 kernel/fork.c:2499
       kernel_clone+0x226/0x8f0 kernel/fork.c:2797
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2875
       rest_init+0x23/0x300 init/main.c:712
       start_kernel+0x47a/0x500 init/main.c:1103
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #2 (&p->pi_lock){-.-.}-{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
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
       try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
       signal_wake_up_state+0xb4/0x120 kernel/signal.c:773
       signal_wake_up include/linux/sched/signal.h:448 [inline]
       complete_signal+0x94a/0xcf0 kernel/signal.c:1065
       __send_signal_locked+0xb1b/0xdc0 kernel/signal.c:1185
       do_notify_parent+0xd96/0x10a0 kernel/signal.c:2141
       exit_notify kernel/exit.c:753 [inline]
       do_exit+0x181d/0x27e0 kernel/exit.c:894
       do_group_exit+0x207/0x2c0 kernel/exit.c:1023
       __do_sys_exit_group kernel/exit.c:1034 [inline]
       __se_sys_exit_group kernel/exit.c:1032 [inline]
       __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 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+0x149/0x2d0 kernel/signal.c:1412
       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:1451
       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
       0xffffffffa000086d
       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
       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:164 [inline]
       get_mmap_lock_carefully mm/memory.c:5716 [inline]
       lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5776
       do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       __put_user_8+0x11/0x20 arch/x86/lib/putuser.S:105
       clear_rseq_cs kernel/rseq.c:257 [inline]
       rseq_ip_fixup kernel/rseq.c:291 [inline]
       __rseq_handle_notify_resume+0x666/0x14e0 kernel/rseq.c:329
       rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
       resume_user_mode_work include/linux/resume_user_mode.h:62 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x114/0x370 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       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+0x18e0/0x5900 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_acquire_returned+0xa8/0x630 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:164 [inline]
       stack_map_get_build_id_offset+0x9af/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:5392 [inline]
       __schedule+0x1066/0x4a20 kernel/sched/core.c:6745
       __schedule_loop kernel/sched/core.c:6822 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6837
       do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2028
       hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2081
       __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+0xf3/0x230 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 syz-executor329/5088:
 #0: ffff8880b943e798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
 #1: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #1: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #1: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline]
 #1: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444
 #2: ffff888020ea0198 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline]
 #2: ffff888020ea0198 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x237/0x9d0 kernel/bpf/stackmap.c:141

stack backtrace:
CPU: 0 PID: 5088 Comm: syz-executor329 Not tainted 6.10.0-rc5-syzkaller-00169-gdc6be0b73f4f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __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+0x18e0/0x5900 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_acquire_returned+0xa8/0x630 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:164 [inline]
 stack_map_get_build_id_offset+0x9af/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:5392 [inline]
 __schedule+0x1066/0x4a20 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2028
 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2081
 __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+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f05e0d9cdf3
Code: Unable to access opcode bytes at 0x7f05e0d9cdc9.
RSP: 002b:00007ffc5ca73888 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00000000000014f5 RCX: 00007f05e0d9cdf3
RDX: 00007ffc5ca738a0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000000f7c8 R08: 000000001a6917cc R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc5ca738dc
R13: 431bde82d7b634db R14: 00007ffc5ca738f0 R15: 0000000000000001
 </TASK>