====================================================== WARNING: possible circular locking dependency detected 6.1.90-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/3937 is trying to acquire lock: ffff8880b9935e90 (lock#11){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9935e90 (lock#11){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237 but task is already holding lock: ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&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:1354 [inline] rq_lock kernel/sched/sched.h:1644 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686 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:699 start_kernel+0x0/0x53f init/main.c:894 start_kernel+0x496/0x53f init/main.c:1141 secondary_startup_64_no_verify+0xcf/0xdb -> #2 (&p->pi_lock){-.-.}-{2:2}: 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:4112 signal_wake_up_state kernel/signal.c:780 [inline] signal_wake_up include/linux/sched/signal.h:457 [inline] complete_signal+0x796/0xbd0 kernel/signal.c:1074 __send_signal_locked+0xb1a/0xdc0 kernel/signal.c:1194 do_notify_parent+0xe2b/0x1100 kernel/signal.c:2120 exit_notify kernel/exit.c:744 [inline] do_exit+0x172e/0x26a0 kernel/exit.c:889 do_group_exit+0x202/0x2b0 kernel/exit.c:1019 __do_sys_exit_group kernel/exit.c:1030 [inline] __se_sys_exit_group kernel/exit.c:1028 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028 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 (&sighand->siglock){-.-.}-{2:2}: 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 __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410 lock_task_sighand include/linux/sched/signal.h:745 [inline] do_send_sig_info kernel/signal.c:1299 [inline] group_send_sig_info+0x26c/0x300 kernel/signal.c:1448 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:882 ____bpf_send_signal kernel/trace/bpf_trace.c:887 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:885 0xffffffffa000096e 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_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5e3/0x670 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:1343 [inline] handle_page_fault arch/x86/mm/fault.c:1462 [inline] exc_page_fault+0x169/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 -> #0 (lock#11){+.+.}-{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 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_e6cf5f9c69743609+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_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2116/0x4550 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 memset+0x2f/0x40 mm/kasan/shadow.c:47 kasan_save_stack mm/kasan/common.c:42 [inline] kasan_set_track+0x3c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x292/0x510 mm/slub.c:3683 kernfs_put+0x325/0x4a0 fs/kernfs/dir.c:562 kernfs_remove_by_name_ns+0xdc/0x150 fs/kernfs/dir.c:1651 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfa/0x2a0 fs/sysfs/group.c:288 sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:312 __kobject_del+0x84/0x310 lib/kobject.c:587 kobject_del+0x41/0x60 lib/kobject.c:619 ext4_put_super+0x75/0x10e0 fs/ext4/super.c:1214 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1459 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: lock#11 --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock(lock#11); *** DEADLOCK *** 5 locks held by syz-executor.4/3937: #0: ffff8880240480e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff888012473548 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove_by_name_ns+0x76/0x150 fs/kernfs/dir.c:1645 #2: ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314 #4: ffff88801f9abd58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #4: ffff88801f9abd58 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x232/0x9c0 kernel/bpf/stackmap.c:144 stack backtrace: CPU: 1 PID: 3937 Comm: syz-executor.4 Not tainted 6.1.90-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+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 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_e6cf5f9c69743609+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_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2116/0x4550 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:memset+0x2f/0x40 mm/kasan/shadow.c:47 Code: 89 d3 41 89 f6 48 89 fd 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 a1 ec ff ff 84 c0 74 12 48 89 ef 44 89 f6 48 89 da 5b 41 5e <5d> e9 1b 9d a6 08 31 c0 5b 41 5e 5d c3 0f 1f 40 00 41 57 41 56 41 RSP: 0018:ffffc90006657820 EFLAGS: 00000202 RAX: 0000000000000f01 RBX: ffff888021072ae8 RCX: ffffffff81e1d82c RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffffc90006657830 RBP: ffffc90006657830 R08: dffffc0000000000 R09: fffff52000ccaf46 R10: 0000000000000006 R11: dffffc0000000001 R12: 0000000000000000 R13: ffffffff8218c245 R14: 0000000000000800 R15: ffffc90006657830 kasan_save_stack mm/kasan/common.c:42 [inline] kasan_set_track+0x3c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x292/0x510 mm/slub.c:3683 kernfs_put+0x325/0x4a0 fs/kernfs/dir.c:562 kernfs_remove_by_name_ns+0xdc/0x150 fs/kernfs/dir.c:1651 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfa/0x2a0 fs/sysfs/group.c:288 sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:312 __kobject_del+0x84/0x310 lib/kobject.c:587 kobject_del+0x41/0x60 lib/kobject.c:619 ext4_put_super+0x75/0x10e0 fs/ext4/super.c:1214 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1459 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f746be7f097 Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffc6cf8c858 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f746be7f097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc6cf8c910 RBP: 00007ffc6cf8c910 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc6cf8d9d0 R13: 00007f746bec937e R14: 000000000002e290 R15: 0000000000000002 EXT4-fs (loop4): unmounting filesystem. ---------------- Code disassembly (best guess): 0: 89 d3 mov %edx,%ebx 2: 41 89 f6 mov %esi,%r14d 5: 48 89 fd mov %rdi,%rbp 8: 48 8b 4c 24 18 mov 0x18(%rsp),%rcx d: 48 89 d6 mov %rdx,%rsi 10: ba 01 00 00 00 mov $0x1,%edx 15: e8 a1 ec ff ff call 0xffffecbb 1a: 84 c0 test %al,%al 1c: 74 12 je 0x30 1e: 48 89 ef mov %rbp,%rdi 21: 44 89 f6 mov %r14d,%esi 24: 48 89 da mov %rbx,%rdx 27: 5b pop %rbx 28: 41 5e pop %r14 * 2a: 5d pop %rbp <-- trapping instruction 2b: e9 1b 9d a6 08 jmp 0x8a69d4b 30: 31 c0 xor %eax,%eax 32: 5b pop %rbx 33: 41 5e pop %r14 35: 5d pop %rbp 36: c3 ret 37: 0f 1f 40 00 nopl 0x0(%rax) 3b: 41 57 push %r15 3d: 41 56 push %r14 3f: 41 rex.B