====================================================== WARNING: possible circular locking dependency detected 6.1.100-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.672/5226 is trying to acquire lock: ffff8880127527d8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4111 but task is already holding lock: ffff8880b9935e90 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9935e90 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 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+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x9d/0x670 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:137 [inline] stack_map_get_build_id_offset+0x99e/0x9c0 kernel/bpf/stackmap.c:144 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:452 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1877 [inline] bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1867 bpf_prog_ec3b2eefa702d8d3+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 trace_tlb_flush+0x151/0x1a0 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x84a/0xc20 context_switch kernel/sched/core.c:5229 [inline] __schedule+0x1152/0x4570 kernel/sched/core.c:6561 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6730 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6754 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 try_to_wake_up+0x87e/0x12e0 kernel/sched/core.c:4233 wake_up_process kernel/sched/core.c:4361 [inline] wake_up_q+0x8b/0xd0 kernel/sched/core.c:1006 futex_wake+0x4ea/0x590 kernel/futex/waitwake.c:184 do_futex+0x375/0x490 kernel/futex/syscalls.c:111 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11878 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4685 copy_process+0x2442/0x4060 kernel/fork.c:2384 kernel_clone+0x222/0x920 kernel/fork.c:2682 user_mode_thread+0x12e/0x190 kernel/fork.c:2758 rest_init+0x23/0x300 init/main.c:698 start_kernel+0x0/0x53f init/main.c:893 start_kernel+0x496/0x53f init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb -> #0 (&p->pi_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4111 rcu_read_unlock_special+0x3d2/0x540 kernel/rcu/tree_plugin.h:655 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] put_memcg_path_buf+0xde/0x110 mm/mmap_lock.c:153 __mmap_lock_do_trace_acquire_returned+0x1f7/0x670 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:137 [inline] get_mmap_lock_carefully mm/memory.c:5304 [inline] lock_mm_and_find_vma+0x219/0x2e0 mm/memory.c:5366 do_user_addr_fault arch/x86/mm/fault.c:1312 [inline] handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x169/0x620 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 strncpy_from_user+0x159/0x360 lib/strncpy_from_user.c:139 strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline] bpf_prog_load+0x188/0x1bb0 kernel/bpf/syscall.c:2530 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5020 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline] __se_sys_bpf kernel/bpf/syscall.c:5122 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &p->pi_lock --> &rq->__lock --> lock#10 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#10); lock(&rq->__lock); lock(lock#10); lock(&p->pi_lock); *** DEADLOCK *** 3 locks held by syz.4.672/5226: #0: ffff88807aea17d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807aea17d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5304 [inline] #0: ffff88807aea17d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2e0 mm/memory.c:5366 #1: ffff8880b9935e90 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b9935e90 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237 #2: ffffffff8d12ad40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #2: ffffffff8d12ad40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #2: ffffffff8d12ad40 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8d12ad40 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 stack backtrace: CPU: 1 PID: 5226 Comm: syz.4.672 Not tainted 6.1.100-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4111 rcu_read_unlock_special+0x3d2/0x540 kernel/rcu/tree_plugin.h:655 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] put_memcg_path_buf+0xde/0x110 mm/mmap_lock.c:153 __mmap_lock_do_trace_acquire_returned+0x1f7/0x670 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:137 [inline] get_mmap_lock_carefully mm/memory.c:5304 [inline] lock_mm_and_find_vma+0x219/0x2e0 mm/memory.c:5366 do_user_addr_fault arch/x86/mm/fault.c:1312 [inline] handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x169/0x620 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0x159/0x360 lib/strncpy_from_user.c:139 Code: 27 fd 48 83 fd 07 0f 86 af 00 00 00 4c 89 64 24 08 4c 89 7c 24 10 48 c7 44 24 18 f8 ff ff ff 45 31 ed 4d 89 f4 48 8b 44 24 08 <4e> 8b 3c 28 48 b8 ff fe fe fe fe fe fe fe 49 8d 1c 07 4d 89 fe 49 RSP: 0018:ffffc9000325fb48 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 00007fffffffef81 RCX: ffff888024589dc0 RDX: ffffc90013e03000 RSI: 000000000000007f RDI: 0000000000000007 RBP: 000000000000007f R08: ffffffff84634991 R09: ffffffff81eec8b3 R10: 0000000000000003 R11: ffff888024589dc0 R12: ffffc9000325fc70 R13: 0000000000000000 R14: ffffc9000325fc70 R15: 000000000000007f strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline] bpf_prog_load+0x188/0x1bb0 kernel/bpf/syscall.c:2530 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5020 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline] __se_sys_bpf kernel/bpf/syscall.c:5122 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f21bfb75b59 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:00007f21c0a07048 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f21bfd03f60 RCX: 00007f21bfb75b59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f21bfbe4e5d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f21bfd03f60 R15: 00007ffce530abf8 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: fd std 1: 48 83 fd 07 cmp $0x7,%rbp 5: 0f 86 af 00 00 00 jbe 0xba b: 4c 89 64 24 08 mov %r12,0x8(%rsp) 10: 4c 89 7c 24 10 mov %r15,0x10(%rsp) 15: 48 c7 44 24 18 f8 ff movq $0xfffffffffffffff8,0x18(%rsp) 1c: ff ff 1e: 45 31 ed xor %r13d,%r13d 21: 4d 89 f4 mov %r14,%r12 24: 48 8b 44 24 08 mov 0x8(%rsp),%rax * 29: 4e 8b 3c 28 mov (%rax,%r13,1),%r15 <-- trapping instruction 2d: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 34: fe fe fe 37: 49 8d 1c 07 lea (%r15,%rax,1),%rbx 3b: 4d 89 fe mov %r15,%r14 3e: 49 rex.WB