random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5312 Comm: syz-executor001 Not tainted 4.19.0-rc4+ #248 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2611 [inline] RIP: 0010:context_switch kernel/sched/core.c:2790 [inline] RIP: 0010:__schedule+0xfb7/0x1ed0 kernel/sched/core.c:3473 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 b9 09 00 00 4d 8b 24 24 4d 85 e4 0f 84 0b f7 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 ed ed 03 fa eb 9d 48 89 de 4c 89 ff e8 00 RSP: 0018:ffff8801c2ddeda8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff8801bdf12600 RCX: 1ffff100375ae88f RDX: 0000000040000000 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff8801c2ddef80 R08: ffff8801d8d20580 R09: fffff520003cc247 R10: fffff520003cc247 R11: ffffc90001e6123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801daf2cb40 R15: ffff8801d8d20580 FS: 0000000001c12880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000043eede CR3: 000000000946a000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: preempt_schedule_common+0x1f/0xd0 kernel/sched/core.c:3597 preempt_schedule+0x4d/0x60 kernel/sched/core.c:3623 ___preempt_schedule+0x16/0x18 smp_call_function_single+0x59a/0x660 kernel/smp.c:304 loaded_vmcs_clear arch/x86/kvm/vmx.c:2218 [inline] free_loaded_vmcs+0x13c/0x1b0 arch/x86/kvm/vmx.c:4749 vmx_free_vcpu+0x204/0x300 arch/x86/kvm/vmx.c:10945 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ad7/0x2610 kernel/exit.c:867 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43ef08 Code: Bad RIP value. RSP: 002b:00007fff592da358 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ef08 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004be7c8 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ====================================================== WARNING: possible circular locking dependency detected 4.19.0-rc4+ #248 Not tainted ------------------------------------------------------ syz-executor001/5312 is trying to acquire lock: 00000000e985bef4 ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 00000000b408c704 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline] 00000000b408c704 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3411 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1821 [inline] task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9581 sched_fork+0x443/0xba0 kernel/sched/core.c:2353 copy_process+0x2586/0x8780 kernel/fork.c:1839 _do_fork+0x1cb/0x11d0 kernel/fork.c:2166 kernel_thread+0x34/0x40 kernel/fork.c:2225 rest_init+0x22/0xe5 init/main.c:408 start_kernel+0x8f4/0x92f init/main.c:739 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 try_to_wake_up+0xd2/0x12f0 kernel/sched/core.c:1960 wake_up_process+0x10/0x20 kernel/sched/core.c:2123 __up.isra.1+0x1c0/0x2a0 kernel/locking/semaphore.c:262 up+0x13c/0x1c0 kernel/locking/semaphore.c:187 __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:244 console_unlock+0x814/0x1160 kernel/printk/printk.c:2427 vprintk_emit+0x33d/0x930 kernel/printk/printk.c:1922 vprintk_default+0x28/0x30 kernel/printk/printk.c:1963 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1996 load_umh+0x51/0xbd net/bpfilter/bpfilter_kern.c:98 do_one_initcall+0x145/0x957 init/main.c:885 do_initcall_level init/main.c:953 [inline] do_initcalls init/main.c:961 [inline] do_basic_setup init/main.c:979 [inline] kernel_init_freeable+0x4bb/0x5ae init/main.c:1144 kernel_init+0x11/0x1b2 init/main.c:1063 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 -> #0 ((console_sem).lock){-...}: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:227 console_trylock+0x15/0xa0 kernel/printk/printk.c:2245 console_trylock_spinning kernel/printk/printk.c:1649 [inline] vprintk_emit+0x322/0x930 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1963 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1996 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:251 notifier_call_chain+0x17e/0x380 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193 notify_die+0x1bd/0x2d0 kernel/notifier.c:549 do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:559 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1160 __fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] prepare_task_switch kernel/sched/core.c:2611 [inline] context_switch kernel/sched/core.c:2790 [inline] __schedule+0xfb7/0x1ed0 kernel/sched/core.c:3473 preempt_schedule_common+0x1f/0xd0 kernel/sched/core.c:3597 preempt_schedule+0x4d/0x60 kernel/sched/core.c:3623 ___preempt_schedule+0x16/0x18 smp_call_function_single+0x59a/0x660 kernel/smp.c:304 loaded_vmcs_clear arch/x86/kvm/vmx.c:2218 [inline] free_loaded_vmcs+0x13c/0x1b0 arch/x86/kvm/vmx.c:4749 vmx_free_vcpu+0x204/0x300 arch/x86/kvm/vmx.c:10945 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ad7/0x2610 kernel/exit.c:867 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syz-executor001/5312: #0: 00000000b408c704 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline] #0: 00000000b408c704 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3411 #1: 00000000753dc81c (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 kernel/notifier.c:329 stack backtrace: CPU: 1 PID: 5312 Comm: syz-executor001 Not tainted 4.19.0-rc4+ #248 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 print_circular_bug.isra.33.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x33e4/0x4ec0 kernel/locking/lockdep.c:3411 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:227 console_trylock+0x15/0xa0 kernel/printk/printk.c:2245 console_trylock_spinning kernel/printk/printk.c:1649 [inline] vprintk_emit+0x322/0x930 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1963 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1996 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:251 notifier_call_chain+0x17e/0x380 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x96/0x190 kernel/notifier.c:193 notify_die+0x1bd/0x2d0 kernel/notifier.c:549 do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:559 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1160 RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2611 [inline] RIP: 0010:context_switch kernel/sched/core.c:2790 [inline] RIP: 0010:__schedule+0xfb7/0x1ed0 kernel/sched/core.c:3473 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 b9 09 00 00 4d 8b 24 24 4d 85 e4 0f 84 0b f7 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 ed ed 03 fa eb 9d 48 89 de 4c 89 ff e8 00 RSP: 0018:ffff8801c2ddeda8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff8801bdf12600 RCX: 1ffff100375ae88f RDX: 0000000040000000 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff8801c2ddef80 R08: ffff8801d8d20580 R09: fffff520003cc247 R10: fffff520003cc247 R11: ffffc90001e6123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801daf2cb40 R15: ffff8801d8d20580 preempt_schedule_common+0x1f/0xd0 kernel/sched/core.c:3597 preempt_schedule+0x4d/0x60 kernel/sched/core.c:3623 ___preempt_schedule+0x16/0x18 smp_call_function_single+0x59a/0x660 kernel/smp.c:304 loaded_vmcs_clear arch/x86/kvm/vmx.c:2218 [inline] free_loaded_vmcs+0x13c/0x1b0 arch/x86/kvm/vmx.c:4749 vmx_free_vcpu+0x204/0x300 arch/x86/kvm/vmx.c:10945 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 Lost 66 message(s)! ---[ end trace 6b0943d3c61e2fe6 ]--- RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2611 [inline] RIP: 0010:context_switch kernel/sched/core.c:2790 [inline] RIP: 0010:__schedule+0xfb7/0x1ed0 kernel/sched/core.c:3473 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 b9 09 00 00 4d 8b 24 24 4d 85 e4 0f 84 0b f7 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 ed ed 03 fa eb 9d 48 89 de 4c 89 ff e8 00 RSP: 0018:ffff8801c2ddeda8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff8801bdf12600 RCX: 1ffff100375ae88f RDX: 0000000040000000 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff8801c2ddef80 R08: ffff8801d8d20580 R09: fffff520003cc247 R10: fffff520003cc247 R11: ffffc90001e6123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801daf2cb40 R15: ffff8801d8d20580 FS: 0000000001c12880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000043eede CR3: 000000000946a000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400