====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-04559-g7d30b8aa4fc3 #0 Not tainted ------------------------------------------------------ syz.3.1887/14704 is trying to acquire lock: ffff888026f7b798 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0x149/0x2d0 kernel/signal.c:1412 but task is already holding lock: ffff8880b9338798 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9338798 (lock#10){+.+.}-{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: -> #2 (lock#10){+.+.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 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:1997 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1987 bpf_prog_682b67a395ac5c66+0x17/0x1b bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5172 [inline] __schedule+0x1079/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2030 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2083 __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 -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1435 [inline] rq_lock_irqsave kernel/sched/sched.h:1700 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1749 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:10245 exit_signals+0x2a1/0x5c0 kernel/signal.c:3022 do_exit+0x6b4/0x27f0 kernel/exit.c:834 __do_sys_exit kernel/exit.c:993 [inline] __se_sys_exit kernel/exit.c:991 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:991 x64_sys_call+0x2622/0x2640 arch/x86/include/generated/asm/syscalls_64.h:61 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:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __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_7aab9edbcd54ca16+0x23/0x28 bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2449 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 user_access_begin arch/x86/include/asm/uaccess.h:521 [inline] check_zeroed_user+0x74/0x190 lib/usercopy.c:78 bpf_check_uarg_tail_zero kernel/bpf/syscall.c:100 [inline] __sys_bpf+0xf6/0x810 kernel/bpf/syscall.c:5676 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 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: &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 syz.3.1887/14704: #0: ffff88807b0c9498 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88807b0c9498 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5716 [inline] #0: ffff88807b0c9498 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5776 #1: ffff8880b9338798 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b9338798 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #2: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #2: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #2: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2449 #4: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #4: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #4: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2d0 kernel/signal.c:1395 stack backtrace: CPU: 1 PID: 14704 Comm: syz.3.1887 Not tainted 6.10.0-syzkaller-04559-g7d30b8aa4fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 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:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __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_7aab9edbcd54ca16+0x23/0x28 bpf_dispatcher_nop_func include/linux/bpf.h:1252 [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:2406 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2449 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 RIP: 0010:check_zeroed_user+0x74/0x190 lib/usercopy.c:81 Code: c2 10 e6 fc 48 89 df 4c 89 fe e8 37 0e e6 fc 4c 89 f0 4c 01 f8 0f 88 fe 00 00 00 4c 39 f8 0f 82 f5 00 00 00 0f 01 cb 0f ae e8 <49> 8b 1f 31 ed 31 ff 4c 89 ee e8 8d 10 e6 fc 42 8d 0c ed 00 00 00 RSP: 0018:ffffc900034d7d28 EFLAGS: 00050212 RAX: 0000000000000300 RBX: 0000000000000300 RCX: ffff888064ac9e00 RDX: ffffc9000a5a1000 RSI: 0000000000000098 RDI: 0000000000000300 RBP: ffffc900034d7ed8 R08: ffffffff84b051e9 R09: 1ffffffff1fecccd R10: dffffc0000000000 R11: fffffbfff1feccce R12: 0000000000000268 R13: 0000000000000000 R14: 0000000000000268 R15: 0000000000000098 bpf_check_uarg_tail_zero kernel/bpf/syscall.c:100 [inline] __sys_bpf+0xf6/0x810 kernel/bpf/syscall.c:5676 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 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: 0033:0x7fc82f777299 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc8304db048 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fc82f905f80 RCX: 00007fc82f777299 RDX: 0000000000000300 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007fc82f7e48e6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc82f905f80 R15: 00007fff55f448d8 ---------------- Code disassembly (best guess): 0: c2 10 e6 ret $0xe610 3: fc cld 4: 48 89 df mov %rbx,%rdi 7: 4c 89 fe mov %r15,%rsi a: e8 37 0e e6 fc call 0xfce60e46 f: 4c 89 f0 mov %r14,%rax 12: 4c 01 f8 add %r15,%rax 15: 0f 88 fe 00 00 00 js 0x119 1b: 4c 39 f8 cmp %r15,%rax 1e: 0f 82 f5 00 00 00 jb 0x119 24: 0f 01 cb stac 27: 0f ae e8 lfence * 2a: 49 8b 1f mov (%r15),%rbx <-- trapping instruction 2d: 31 ed xor %ebp,%ebp 2f: 31 ff xor %edi,%edi 31: 4c 89 ee mov %r13,%rsi 34: e8 8d 10 e6 fc call 0xfce610c6 39: 42 rex.X 3a: 8d .byte 0x8d 3b: 0c ed or $0xed,%al 3d: 00 00 add %al,(%rax)