====================================================== WARNING: possible circular locking dependency detected 6.9.0-syzkaller-12148-g61ce0ea7591f #0 Not tainted ------------------------------------------------------ sshd/5084 is trying to acquire lock: ffff888028958958 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x149/0x2d0 kernel/signal.c:1412 but task is already holding lock: ffff8880b9538828 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9538828 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (lock#9){+.+.}-{2:2}: 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 0xffffffffa000081a 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 ptrace_stop+0x5b4/0x940 kernel/signal.c:2356 ptrace_do_notify kernel/signal.c:2393 [inline] ptrace_notify+0x255/0x380 kernel/signal.c:2405 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_entry include/linux/ptrace.h:452 [inline] syscall_trace_enter+0x5d/0x150 kernel/entry/common.c:45 syscall_enter_from_user_mode_work include/linux/entry-common.h:168 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:198 [inline] do_syscall_64+0xcc/0x230 arch/x86/entry/common.c:79 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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: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 -> #1 (&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 -> #0 (&sighand->siglock){-...}-{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 __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 bpf_prog_7bb747c56a8bcba8+0x1d/0x25 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] task_numa_work+0x13c4/0x13f0 kernel/sched/fair.c:3262 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#9 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#9); lock(&rq->__lock); lock(lock#9); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by sshd/5084: #0: ffff88807b44b118 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88807b44b118 (&mm->mmap_lock){++++}-{3:3}, at: task_numa_work+0x363/0x13f0 kernel/sched/fair.c:3262 #1: ffff8880b9538828 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b9538828 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2446 #4: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2d0 kernel/signal.c:1395 stack backtrace: CPU: 1 PID: 5084 Comm: sshd Not tainted 6.9.0-syzkaller-12148-g61ce0ea7591f #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+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 __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 bpf_prog_7bb747c56a8bcba8+0x1d/0x25 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] task_numa_work+0x13c4/0x13f0 kernel/sched/fair.c:3262 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [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+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8c0f6c2773 Code: 00 f3 a5 48 8d 74 24 88 48 b9 ff ff ff 7f fe ff ff ff 48 21 c8 48 89 44 24 88 41 ba 08 00 00 00 44 89 c7 b8 0e 00 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 06 41 89 c0 41 f7 d8 44 89 c0 5a c3 41 RSP: 002b:00007ffd6fb66270 EFLAGS: 00000246 ORIG_RAX: 000000000000000e RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8c0f6c2773 RDX: 00007ffd6fb66358 RSI: 00007ffd6fb662d8 RDI: 0000000000000000 RBP: 000055d641254570 R08: 0000000000000000 R09: 0000000000000000 R10: 000000