====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc7-syzkaller #0 Not tainted ------------------------------------------------------ dhcpcd-run-hook/5541 is trying to acquire lock: ffff888025c50958 (&sighand->siglock){....}-{2:2}, at: __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 but task is already holding lock: ffff8880b94387a8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b94387a8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x620 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#10){+.+.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x620 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] stack_map_get_build_id_offset+0x9b2/0x9d0 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:1985 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_tlb_flush+0x112/0x130 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x796/0xab0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x12d3/0x4be0 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+0x88/0x170 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&rq->__lock){-.-.}-{2:2}: _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+0x6a8/0x27d0 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+0x88/0x170 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3a23/0x7fa0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x540 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 kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_da8cbe553dc44a71+0x22/0x29 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5ba/0x620 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+0x20b/0x860 arch/x86/mm/fault.c:1532 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+0x666/0x14d0 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+0x113/0x360 kernel/entry/common.c:218 do_syscall_64+0x94/0x170 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e 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 *** 5 locks held by dhcpcd-run-hook/5541: #0: ffff88807b775e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff88807b775e20 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5633 [inline] #0: ffff88807b775e20 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5693 #1: ffff8880b94387a8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b94387a8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x620 mm/mmap_lock.c:237 #2: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #3: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16e/0x490 kernel/trace/bpf_trace.c:2422 #4: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2e0 kernel/signal.c:1397 stack backtrace: CPU: 0 PID: 5541 Comm: dhcpcd-run-hook Not tainted 6.9.0-rc7-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+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x379/0x4b0 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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3a23/0x7fa0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x540 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 kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_da8cbe553dc44a71+0x22/0x29 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5ba/0x620 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+0x20b/0x860 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_8+0x11/0x20 arch/x86/lib/putuser.S:107 Code: 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <48> 89 01 31 c9 0f 01 ca c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000532fd98 EFLAGS: 00050206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f5b60f71d28 RDX: 0000000000000000 RSI: ffffffff8b6ab080 RDI: ffffffff8bbaca80 RBP: ffffc9000532fed8 R08: ffffffff8f3f7d6f R09: 1ffffffff1e7efad R10: dffffc0000000000 R11: fffffbfff1e7efae R12: ffffc9000532fe50 R13: ffffc9000532ffd8 R14: dffffc0000000000 R15: ffff88807bf41550 clear_rseq_cs kernel/rseq.c:257 [inline] rseq_ip_fixup kernel/rseq.c:291 [inline] __rseq_handle_notify_resume+0x666/0x14d0 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+0x113/0x360 kernel/entry/common.c:218 do_syscall_64+0x94/0x170 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f5b610aba12 Code: 41 5d 41 5e 41 5f c3 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 e7 43 0f 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffec36dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: 00000000000015b0 RBX: 0000000000000001 RCX: 00007f5b610aba12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00005558011bfb70 R08: 0000000000000000 R09: f4b682869f18140d R10: 00007f5b60f71650 R11: 0000000000000246 R12: 0000000000000084 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000024 ---------------- Code disassembly (best guess): 0: 84 00 test %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 0f 1f 00 nopl (%rax) 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: f3 0f 1e fa endbr64 1d: 48 89 cb mov %rcx,%rbx 20: 48 c1 fb 3f sar $0x3f,%rbx 24: 48 09 d9 or %rbx,%rcx 27: 0f 01 cb stac * 2a: 48 89 01 mov %rax,(%rcx) <-- trapping instruction 2d: 31 c9 xor %ecx,%ecx 2f: 0f 01 ca clac 32: c3 ret 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: 66 90 xchg %ax,%ax 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop