====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc1-syzkaller-00304-g83814698cf48 #0 Not tainted ------------------------------------------------------ dhcpcd-run-hook/11285 is trying to acquire lock: ffff88802797ca18 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1412 but task is already holding lock: ffff88806b138ac0 (lock#13){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff88806b138ac0 (lock#13){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x790 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#13){+.+.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 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+0x5d9/0x7c0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1984 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_tlb_flush+0xd2/0x110 include/trace/events/tlb.h:38 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x68b/0xbc0 arch/x86/mm/tlb.c:642 context_switch kernel/sched/core.c:5392 [inline] __schedule+0xd2b/0x5d00 kernel/sched/core.c:6745 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6924 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 __debug_object_init+0x34a/0x480 lib/debugobjects.c:645 hrtimer_init_sleeper_on_stack kernel/time/hrtimer.c:448 [inline] schedule_hrtimeout_range_clock+0x145/0x430 kernel/time/hrtimer.c:2284 poll_schedule_timeout.constprop.0+0xba/0x190 fs/select.c:244 do_poll fs/select.c:965 [inline] do_sys_poll+0xae2/0xde0 fs/select.c:1016 __do_sys_ppoll fs/select.c:1122 [inline] __se_sys_ppoll fs/select.c:1102 [inline] __x64_sys_ppoll+0x25a/0x2d0 fs/select.c:1102 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1406 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1425 [inline] rq_lock_irqsave kernel/sched/sched.h:1686 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1740 [inline] sched_mm_cid_before_execve+0x114/0x5e0 kernel/sched/core.c:12026 exit_signals+0x34d/0x960 kernel/signal.c:3014 do_exit+0x54e/0x2ba0 kernel/exit.c:833 __do_sys_exit kernel/exit.c:990 [inline] __se_sys_exit kernel/exit.c:988 [inline] __x64_sys_exit+0x42/0x50 kernel/exit.c:988 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 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+0x290/0x300 kernel/signal.c:1451 bpf_send_signal_common+0x2e8/0x3a0 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_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x245/0x5a0 kernel/trace/bpf_trace.c:2446 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 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+0x456/0x790 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:5715 [inline] lock_mm_and_find_vma+0xeb/0x6a0 mm/memory.c:5775 do_user_addr_fault+0x29c/0xe50 arch/x86/mm/fault.c:1361 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:92 __clear_user arch/x86/include/asm/uaccess_64.h:172 [inline] copy_fpstate_to_sigframe+0x316/0xaa0 arch/x86/kernel/fpu/signal.c:236 get_sigframe+0x455/0x930 arch/x86/kernel/signal.c:142 x64_setup_rt_frame+0x129/0xce0 arch/x86/kernel/signal_64.c:175 setup_rt_frame arch/x86/kernel/signal.c:223 [inline] handle_signal arch/x86/kernel/signal.c:267 [inline] arch_do_signal_or_restart+0x5e6/0x7e0 arch/x86/kernel/signal.c:312 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 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#13 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#13); lock(&rq->__lock); lock(lock#13); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by dhcpcd-run-hook/11285: #0: ffff88802a028b18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88802a028b18 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5715 [inline] #0: ffff88802a028b18 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x35/0x6a0 mm/memory.c:5775 #1: ffff88806b138ac0 (lock#13){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff88806b138ac0 (lock#13){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x790 mm/mmap_lock.c:237 #2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x6f0 mm/mmap_lock.c:209 #3: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2446 #4: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8dbb18e0 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x3f/0x340 kernel/signal.c:1395 stack backtrace: CPU: 1 PID: 11285 Comm: dhcpcd-run-hook Not tainted 6.10.0-rc1-syzkaller-00304-g83814698cf48 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 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+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 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+0x290/0x300 kernel/signal.c:1451 bpf_send_signal_common+0x2e8/0x3a0 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_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x245/0x5a0 kernel/trace/bpf_trace.c:2446 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 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+0x456/0x790 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:5715 [inline] lock_mm_and_find_vma+0xeb/0x6a0 mm/memory.c:5775 do_user_addr_fault+0x29c/0xe50 arch/x86/mm/fault.c:1361 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:96 Code: ff c7 48 ff c9 75 f6 c3 cc cc cc cc 48 89 07 48 83 c7 08 83 e9 08 74 ef 83 f9 08 73 ef eb de 66 66 2e 0f 1f 84 00 00 00 00 00 <48> 89 07 48 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 RSP: 0018:ffffc900038a7b10 EFLAGS: 00050202 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000a80 RDX: ffff888027a1c880 RSI: ffffffff813364d6 RDI: 00007ffeb90cce80 RBP: 0000000000000a80 R08: 0000000000000000 R09: fffffbfff1fc8c7a R10: ffffffff8fe463d7 R11: 0000000000000000 R12: ffff888027a1c880 R13: 00007ffeb90cce80 R14: ffff888027a1c880 R15: ffff888027a1e200 __clear_user arch/x86/include/asm/uaccess_64.h:172 [inline] copy_fpstate_to_sigframe+0x316/0xaa0 arch/x86/kernel/fpu/signal.c:236 get_sigframe+0x455/0x930 arch/x86/kernel/signal.c:142 x64_setup_rt_frame+0x129/0xce0 arch/x86/kernel/signal_64.c:175 setup_rt_frame arch/x86/kernel/signal.c:223 [inline] handle_signal arch/x86/kernel/signal.c:267 [inline] arch_do_signal_or_restart+0x5e6/0x7e0 arch/x86/kernel/signal.c:312 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc84d22476 Code: 10 00 00 00 48 89 d1 89 f2 48 89 fe 83 cf ff e9 00 00 00 00 49 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 73 48 8b 15 83 49 0f 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffeb90cd9a8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: 0000000000002c17 RBX: 0000000000000001 RCX: 00007fdc84d22476 RDX: 0000000000000000 RSI: 00007ffeb90cd9cc RDI: 00000000ffffffff RBP: 0000562917e20930 R08: 0000000000002c17 R09: 0000000000000200 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000562917e1f2c0 R14: 00007fdc84ee8470 R15: 0000000000000024 ---------------- Code disassembly (best guess): 0: ff c7 inc %edi 2: 48 ff c9 dec %rcx 5: 75 f6 jne 0xfffffffd 7: c3 ret 8: cc int3 9: cc int3 a: cc int3 b: cc int3 c: 48 89 07 mov %rax,(%rdi) f: 48 83 c7 08 add $0x8,%rdi 13: 83 e9 08 sub $0x8,%ecx 16: 74 ef je 0x7 18: 83 f9 08 cmp $0x8,%ecx 1b: 73 ef jae 0xc 1d: eb de jmp 0xfffffffd 1f: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) 26: 00 00 00 00 * 2a: 48 89 07 mov %rax,(%rdi) <-- trapping instruction 2d: 48 89 47 08 mov %rax,0x8(%rdi) 31: 48 89 47 10 mov %rax,0x10(%rdi) 35: 48 89 47 18 mov %rax,0x18(%rdi) 39: 48 89 47 20 mov %rax,0x20(%rdi) 3d: 48 rex.W 3e: 89 .byte 0x89 3f: 47 rex.RXB