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: 0 PID: 8298 Comm: syz-executor0 Not tainted 4.19.0-rc4-next-20180921+ #77 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:2502 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2510 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2616 [inline] RIP: 0010:context_switch kernel/sched/core.c:2795 [inline] RIP: 0010:__schedule+0x1144/0x1ed0 kernel/sched/core.c:3479 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 7e 08 00 00 4d 8b 24 24 4d 85 e4 0f 84 7e f5 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 e0 bb 00 fa eb 9d 48 8d bb 28 04 00 00 48 RSP: 0018:ffff88018705f1a8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff880191a80000 RCX: 1ffff100322788af RDX: 0000000040000002 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff88018705f380 R08: ffff880187052040 R09: fffff52001c64247 R10: fffff52001c64247 R11: ffffc9000e32123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801dac2cc40 R15: ffff880187052040 FS: 00007faec0edc700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdb4f61a48 CR3: 00000001be2e9000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: schedule+0xfe/0x460 kernel/sched/core.c:3523 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3f9/0x840 kernel/futex.c:2530 futex_wait+0x45c/0xa50 kernel/futex.c:2645 do_futex+0x31a/0x26d0 kernel/futex.c:3528 __do_sys_futex kernel/futex.c:3589 [inline] __se_sys_futex kernel/futex.c:3557 [inline] __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007faec0edbcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000072bf08 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c R13: 00007fffb2f05dcf R14: 00007faec0edc9c0 R15: 0000000000000000 Modules linked in: ====================================================== WARNING: possible circular locking dependency detected 4.19.0-rc4-next-20180921+ #77 Not tainted ------------------------------------------------------ syz-executor0/8298 is trying to acquire lock: 00000000ef87bc4b ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 000000002db41d21 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1125 [inline] 000000002db41d21 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3417 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:1125 [inline] task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9674 sched_fork+0x443/0xba0 kernel/sched/core.c:2358 copy_process+0x2585/0x8780 kernel/fork.c:1887 _do_fork+0x1cb/0x11c0 kernel/fork.c:2216 kernel_thread+0x34/0x40 kernel/fork.c:2275 rest_init+0x22/0xe5 init/main.c:408 start_kernel+0x8bc/0x8f7 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:1964 wake_up_process+0x10/0x20 kernel/sched/core.c:2128 __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:243 console_unlock+0x80c/0x1150 kernel/printk/printk.c:2426 vprintk_emit+0x33d/0x930 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1962 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1995 load_umh+0x51/0xbd net/bpfilter/bpfilter_kern.c:98 do_one_initcall+0x140/0x956 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:352 -> #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:226 console_trylock+0x15/0xa0 kernel/printk/printk.c:2244 console_trylock_spinning kernel/printk/printk.c:1648 [inline] vprintk_emit+0x322/0x930 kernel/printk/printk.c:1920 vprintk_default+0x28/0x30 kernel/printk/printk.c:1962 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1995 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:250 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+0x25b/0x340 arch/x86/kernel/traps.c:573 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1138 __fire_sched_out_preempt_notifiers kernel/sched/core.c:2502 [inline] fire_sched_out_preempt_notifiers kernel/sched/core.c:2510 [inline] prepare_task_switch kernel/sched/core.c:2616 [inline] context_switch kernel/sched/core.c:2795 [inline] __schedule+0x1144/0x1ed0 kernel/sched/core.c:3479 schedule+0xfe/0x460 kernel/sched/core.c:3523 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3f9/0x840 kernel/futex.c:2530 futex_wait+0x45c/0xa50 kernel/futex.c:2645 do_futex+0x31a/0x26d0 kernel/futex.c:3528 __do_sys_futex kernel/futex.c:3589 [inline] __se_sys_futex kernel/futex.c:3557 [inline] __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557 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-executor0/8298: #0: 000000002db41d21 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1125 [inline] #0: 000000002db41d21 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3417 #1: 000000000a39a287 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 kernel/notifier.c:329 stack backtrace: CPU: 0 PID: 8298 Comm: syz-executor0 Not tainted 4.19.0-rc4-next-20180921+ #77 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+0x1d3/0x2c4 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:226 console_trylock+0x15/0xa0 kernel/printk/printk.c:2244 console_trylock_spinning kernel/printk/printk.c:1648 [inline] vprintk_emit+0x322/0x930 kernel/printk/printk.c:1920 vprintk_default+0x28/0x30 kernel/printk/printk.c:1962 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1995 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:250 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+0x25b/0x340 arch/x86/kernel/traps.c:573 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1138 RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2502 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2510 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2616 [inline] RIP: 0010:context_switch kernel/sched/core.c:2795 [inline] RIP: 0010:__schedule+0x1144/0x1ed0 kernel/sched/core.c:3479 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 7e 08 00 00 4d 8b 24 24 4d 85 e4 0f 84 7e f5 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 e0 bb 00 fa eb 9d 48 8d bb 28 04 00 00 48 RSP: 0018:ffff88018705f1a8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff880191a80000 RCX: 1ffff100322788af RDX: 0000000040000002 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff88018705f380 R08: ffff880187052040 R09: fffff52001c64247 R10: fffff52001c64247 R11: ffffc9000e32123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801dac2cc40 R15: ffff880187052040 schedule+0xfe/0x460 kernel/sched/core.c:3523 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3f9/0x840 kernel/futex.c:2530 futex_wait+0x45c/0xa50 kernel/futex.c:2645 do_futex+0x31a/0x26d0 kernel/futex.c:3528 __do_sys_futex kernel/futex.c:3589 [inline] __se_sys_futex kernel/futex.c:3557 [inline] __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 ? entry_SYSCALL_64_after Lost 16 message(s)! ---[ end trace 97cfe5aec544ec7f ]--- RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2502 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2510 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2616 [inline] RIP: 0010:context_switch kernel/sched/core.c:2795 [inline] RIP: 0010:__schedule+0x1144/0x1ed0 kernel/sched/core.c:3479 Code: 89 e0 48 c1 e8 03 42 80 3c 28 00 0f 85 7e 08 00 00 4d 8b 24 24 4d 85 e4 0f 84 7e f5 ff ff 49 8d 7c 24 10 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 a4 e8 e0 bb 00 fa eb 9d 48 8d bb 28 04 00 00 48 RSP: 0018:ffff88018705f1a8 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff880191a80000 RCX: 1ffff100322788af RDX: 0000000040000002 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff88018705f380 R08: ffff880187052040 R09: fffff52001c64247 R10: fffff52001c64247 R11: ffffc9000e32123b R12: dead000000000100 R13: dffffc0000000000 R14: ffff8801dac2cc40 R15: ffff880187052040 FS: 00007faec0edc700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdb4f61a48 CR3: 00000001be2e9000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400