------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 5.15.164-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:2/1074 is trying to acquire lock: ffffffff8c7fc378 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 but task is already holding lock: ffff8880b9a2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1690 [inline] ffff8880b9a2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (hrtimer_bases.lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] hrtimer_start_range_ns+0xd8/0xc50 kernel/time/hrtimer.c:1297 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] do_start_rt_bandwidth kernel/sched/rt.c:69 [inline] start_rt_bandwidth kernel/sched/rt.c:80 [inline] inc_rt_group kernel/sched/rt.c:1207 [inline] inc_rt_tasks kernel/sched/rt.c:1251 [inline] __enqueue_rt_entity kernel/sched/rt.c:1321 [inline] enqueue_rt_entity kernel/sched/rt.c:1368 [inline] enqueue_task_rt+0x5a0/0xbf0 kernel/sched/rt.c:1398 enqueue_task+0x181/0x3a0 kernel/sched/core.c:1977 __sched_setscheduler+0x13bf/0x1e20 kernel/sched/core.c:7551 _sched_setscheduler kernel/sched/core.c:7598 [inline] sched_setscheduler_nocheck kernel/sched/core.c:7645 [inline] sched_set_fifo+0x10e/0x1e0 kernel/sched/core.c:7669 drm_vblank_worker_init+0x149/0x190 drivers/gpu/drm/drm_vblank_work.c:263 drm_vblank_init+0x274/0x330 drivers/gpu/drm/drm_vblank.c:551 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:195 [inline] vkms_init+0x330/0x6d0 drivers/gpu/drm/vkms/vkms_drv.c:235 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #3 (&rt_b->rt_runtime_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 __enable_runtime kernel/sched/rt.c:840 [inline] rq_online_rt+0x123/0x300 kernel/sched/rt.c:2331 set_rq_online kernel/sched/core.c:9037 [inline] sched_cpu_activate+0x508/0x6b0 kernel/sched/core.c:9144 cpuhp_invoke_callback+0x49f/0x820 kernel/cpu.c:191 cpuhp_thread_fun+0x3ee/0x790 kernel/cpu.c:822 smpboot_thread_fn+0x51b/0x9d0 kernel/smpboot.c:164 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11495 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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+0xae/0x1300 kernel/sched/core.c:4030 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0xf8/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2760 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274 _printk+0xd1/0x120 kernel/printk/printk.c:2299 can_stop_idle_tick+0x258/0x2b0 kernel/time/tick-sched.c:1057 tick_nohz_get_sleep_length+0x124/0x1e0 kernel/time/tick-sched.c:1228 menu_select+0x610/0x1c90 drivers/cpuidle/governors/menu.c:283 cpuidle_idle_call kernel/sched/idle.c:232 [inline] do_idle+0x363/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x371/0x500 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:566 copy_from_user_nofault+0x15c/0x1c0 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0xf3c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] delay_tsc+0x58/0xd0 arch/x86/lib/delay.c:78 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Chain exists of: (console_sem).lock --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(&rt_b->rt_runtime_lock); lock(hrtimer_bases.lock); lock((console_sem).lock); *** DEADLOCK *** 5 locks held by kworker/0:2/1074: #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900046b7d20 ((work_completion)(&(&ssp->work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff914d2980 (&ssp->srcu_gp_mutex){+.+.}-{3:3}, at: srcu_advance_state kernel/rcu/srcutree.c:1177 [inline] #2: ffffffff914d2980 (&ssp->srcu_gp_mutex){+.+.}-{3:3}, at: process_srcu+0x2f/0xc20 kernel/rcu/srcutree.c:1325 #3: ffff8880b9a2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1690 [inline] #3: ffff8880b9a2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750 #4: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 1074 Comm: kworker/0:2 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: rcu_gp process_srcu Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:566 RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 cb c9 d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 b4 c9 d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0018:ffffc90000007be0 EFLAGS: 00010046 RAX: ffffffff81aa97ac RBX: 0000000000000000 RCX: ffff88801bf2bb80 RDX: 0000000000010002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aa96bd R09: fffffbfff1f8e019 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000008 R14: 0000000000000000 R15: ffffc90000007c48 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0xf3c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:delay_tsc+0x58/0xd0 arch/x86/lib/delay.c:79 Code: 90 48 89 d5 48 c1 e5 20 48 09 c5 48 29 dd 4c 39 f5 73 67 bf 01 00 00 00 e8 85 7b 26 fd 65 8b 05 46 80 d1 7b 85 c0 74 2f f3 90 01 00 00 00 e8 ee 79 26 fd e8 89 31 02 06 41 39 c7 75 20 0f 01 RSP: 0018:ffffc900046b7ae0 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000003b1a2a6220 RCX: 0000000000000001 RDX: 000000000000003b RSI: ffffffff8ad8f7e0 RDI: 0000000000000001 RBP: 0000000000000a2a R08: ffffffff842b91f4 R09: fffff520008d6f2d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000007583 R13: 1ffffffff1bd29c7 R14: 0000000000002afa R15: 0000000000000000 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 WARNING: CPU: 0 PID: 1074 at mm/maccess.c:226 copy_from_user_nofault+0x15c/0x1c0 Modules linked in: CPU: 0 PID: 1074 Comm: kworker/0:2 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: rcu_gp process_srcu RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 cb c9 d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 b4 c9 d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0018:ffffc90000007be0 EFLAGS: 00010046 RAX: ffffffff81aa97ac RBX: 0000000000000000 RCX: ffff88801bf2bb80 RDX: 0000000000010002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aa96bd R09: fffffbfff1f8e019 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000008 R14: 0000000000000000 R15: ffffc90000007c48 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa6ecd6ad60 CR3: 0000000079c9a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0xf3c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:delay_tsc+0x58/0xd0 arch/x86/lib/delay.c:79 Code: 90 48 89 d5 48 c1 e5 20 48 09 c5 48 29 dd 4c 39 f5 73 67 bf 01 00 00 00 e8 85 7b 26 fd 65 8b 05 46 80 d1 7b 85 c0 74 2f f3 90 01 00 00 00 e8 ee 79 26 fd e8 89 31 02 06 41 39 c7 75 20 0f 01 RSP: 0018:ffffc900046b7ae0 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000003b1a2a6220 RCX: 0000000000000001 RDX: 000000000000003b RSI: ffffffff8ad8f7e0 RDI: 0000000000000001 RBP: 0000000000000a2a R08: ffffffff842b91f4 R09: fffff520008d6f2d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000007583 R13: 1ffffffff1bd29c7 R14: 0000000000002afa R15: 0000000000000000 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 ---------------- Code disassembly (best guess): 0: 90 nop 1: 48 89 d5 mov %rdx,%rbp 4: 48 c1 e5 20 shl $0x20,%rbp 8: 48 09 c5 or %rax,%rbp b: 48 29 dd sub %rbx,%rbp e: 4c 39 f5 cmp %r14,%rbp 11: 73 67 jae 0x7a 13: bf 01 00 00 00 mov $0x1,%edi 18: e8 85 7b 26 fd call 0xfd267ba2 1d: 65 8b 05 46 80 d1 7b mov %gs:0x7bd18046(%rip),%eax # 0x7bd1806a 24: 85 c0 test %eax,%eax 26: 74 2f je 0x57 28: f3 90 pause * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 ee 79 26 fd call 0xfd267a22 34: e8 89 31 02 06 call 0x60231c2 39: 41 39 c7 cmp %eax,%r15d 3c: 75 20 jne 0x5e 3e: 0f .byte 0xf 3f: 01 .byte 0x1