================================================================== kasan: CONFIG_KASAN_INLINE enabled BUG: KASAN: stack-out-of-bounds in timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 kasan: GPF could be caused by NULL-ptr deref or user memory access Read of size 8 at addr ffff8880a941f478 by task syz-executor881/7978 general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 3 Comm: Not tainted 4.20.0-rc7-next-20181224 #1 CPU: 0 PID: 7978 Comm: syz-executor881 Not tainted 4.20.0-rc7-next-20181224 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:191 [inline] RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline] RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline] RIP: 0010:account_system_index_time+0xe8/0x5f0 kernel/sched/cputime.c:168 Call Trace: Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d b8 40 01 00 00 48 8d 88 28 01 00 00 48 89 fe 48 c1 ee 03 <0f> b6 14 16 48 89 fe 83 e6 07 40 38 f2 7f 08 84 d2 0f 85 93 03 00 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006 RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3 RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff1335b3d R10: fffffbfff1301b45 R11: ffffffff899ad9e3 R12: ffff8880a94c4440 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 R13: 000000000077a391 R14: 0000000000000003 R15: ffff8880ae707b20 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 CR2: 00000000006d7090 CR3: 0000000096f60000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 Call Trace: timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 enqueue_hrtimer+0x1ae/0x570 kernel/time/hrtimer.c:951 __hrtimer_start_range_ns kernel/time/hrtimer.c:1080 [inline] hrtimer_start_range_ns+0x62a/0xda0 kernel/time/hrtimer.c:1106 irqtime_account_process_tick.isra.0+0x3a2/0x490 kernel/sched/cputime.c:380 account_process_tick+0x27f/0x350 kernel/sched/cputime.c:483 update_process_times+0x25/0x80 kernel/time/timer.c:1633 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] do_nanosleep+0x1a2/0x750 kernel/time/hrtimer.c:1676 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1754 [inline] __x64_sys_nanosleep+0x1e0/0x280 kernel/time/hrtimer.c:1754 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 entry_SYSCALL_64_after_hwframe+0x49/0xbe Modules linked in: RIP: 0033:0x443ae0 ====================================================== WARNING: possible circular locking dependency detected 4.20.0-rc7-next-20181224 #1 Not tainted ------------------------------------------------------ syz-executor881/7978 is trying to acquire lock: 000000007874c6ae ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 000000001e99e9d7 (report_lock){....}, at: start_report mm/kasan/report.c:85 [inline] 000000001e99e9d7 (report_lock){....}, at: kasan_report+0xb1/0x15e mm/kasan/report.c:309 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (report_lock){....}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 start_report mm/kasan/report.c:85 [inline] kasan_report+0xb1/0x15e mm/kasan/report.c:309 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 enqueue_hrtimer+0x1ae/0x570 kernel/time/hrtimer.c:951 __hrtimer_start_range_ns kernel/time/hrtimer.c:1080 [inline] hrtimer_start_range_ns+0x62a/0xda0 kernel/time/hrtimer.c:1106 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] do_nanosleep+0x1a2/0x750 kernel/time/hrtimer.c:1676 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1754 [inline] __x64_sys_nanosleep+0x1e0/0x280 kernel/time/hrtimer.c:1754 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #4 (hrtimer_bases.lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 lock_hrtimer_base.isra.0+0x75/0x130 kernel/time/hrtimer.c:165 hrtimer_start_range_ns+0x120/0xda0 kernel/time/hrtimer.c:1104 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] start_rt_bandwidth kernel/sched/rt.c:70 [inline] inc_rt_group kernel/sched/rt.c:1147 [inline] inc_rt_tasks kernel/sched/rt.c:1191 [inline] __enqueue_rt_entity kernel/sched/rt.c:1261 [inline] enqueue_rt_entity kernel/sched/rt.c:1305 [inline] enqueue_task_rt+0x95b/0x1010 kernel/sched/rt.c:1335 enqueue_task+0xb9/0x380 kernel/sched/core.c:730 __sched_setscheduler+0xe32/0x1fe0 kernel/sched/core.c:4336 _sched_setscheduler+0x218/0x340 kernel/sched/core.c:4373 sched_setscheduler+0xe/0x10 kernel/sched/core.c:4388 watchdog_dev_init+0x109/0x1db drivers/watchdog/watchdog_dev.c:1144 watchdog_init+0x81/0x294 drivers/watchdog/watchdog_core.c:355 do_one_initcall+0x129/0x937 init/main.c:888 do_initcall_level init/main.c:956 [inline] do_initcalls init/main.c:964 [inline] do_basic_setup init/main.c:982 [inline] kernel_init_freeable+0x4db/0x5ca init/main.c:1135 kernel_init+0x12/0x1c5 init/main.c:1055 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 -> #3 (&rt_b->rt_runtime_lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 __enable_runtime kernel/sched/rt.c:786 [inline] rq_online_rt+0xb4/0x390 kernel/sched/rt.c:2178 set_rq_online.part.0+0xe7/0x140 kernel/sched/core.c:5666 set_rq_online kernel/sched/core.c:5772 [inline] sched_cpu_activate+0x29e/0x430 kernel/sched/core.c:5765 cpuhp_invoke_callback+0x2f6/0x2110 kernel/cpu.c:168 cpuhp_thread_fun+0x496/0x8a0 kernel/cpu.c:685 smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1149 [inline] task_fork_fair+0xb5/0x7a0 kernel/sched/fair.c:10083 sched_fork+0x437/0xb90 kernel/sched/core.c:2359 copy_process+0x1ff6/0x8720 kernel/fork.c:1887 _do_fork+0x1a9/0x1170 kernel/fork.c:2216 kernel_thread+0x34/0x40 kernel/fork.c:2275 rest_init+0x28/0x37b init/main.c:408 arch_call_rest_init+0xe/0x1b start_kernel+0x882/0x8bd init/main.c:740 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 try_to_wake_up+0xb9/0x1480 kernel/sched/core.c:1965 wake_up_process+0x10/0x20 kernel/sched/core.c:2129 __up.isra.0+0x1c0/0x2a0 kernel/locking/semaphore.c:262 up+0x13e/0x1c0 kernel/locking/semaphore.c:187 __up_console_sem+0xb7/0x1c0 kernel/printk/printk.c:236 console_unlock+0x743/0x1040 kernel/printk/printk.c:2473 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978 vprintk_default+0x28/0x30 kernel/printk/printk.c:2005 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2038 check_stack_usage kernel/exit.c:755 [inline] do_exit.cold+0x57/0x16a kernel/exit.c:916 do_group_exit+0x177/0x430 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+0x44/0x50 kernel/exit.c:979 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2289 console_trylock_spinning kernel/printk/printk.c:1709 [inline] vprintk_emit+0x351/0x960 kernel/printk/printk.c:1977 vprintk_default+0x28/0x30 kernel/printk/printk.c:2005 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2038 start_report mm/kasan/report.c:86 [inline] kasan_report+0xc1/0x15e mm/kasan/report.c:309 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 enqueue_hrtimer+0x1ae/0x570 kernel/time/hrtimer.c:951 __hrtimer_start_range_ns kernel/time/hrtimer.c:1080 [inline] hrtimer_start_range_ns+0x62a/0xda0 kernel/time/hrtimer.c:1106 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] do_nanosleep+0x1a2/0x750 kernel/time/hrtimer.c:1676 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1754 [inline] __x64_sys_nanosleep+0x1e0/0x280 kernel/time/hrtimer.c:1754 do_syscall_64+0x1a3/0x800 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 --> hrtimer_bases.lock --> report_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(report_lock); lock(hrtimer_bases.lock); lock(report_lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syz-executor881/7978: #0: 0000000053a4f5fc (hrtimer_bases.lock){-.-.}, at: lock_hrtimer_base.isra.0+0x75/0x130 kernel/time/hrtimer.c:165 #1: 000000001e99e9d7 (report_lock){....}, at: start_report mm/kasan/report.c:85 [inline] #1: 000000001e99e9d7 (report_lock){....}, at: kasan_report+0xb1/0x15e mm/kasan/report.c:309 stack backtrace: CPU: 0 PID: 7978 Comm: syz-executor881 Not tainted 4.20.0-rc7-next-20181224 #1 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+0x1db/0x2d0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2350 [inline] __lock_acquire+0x2fed/0x4a10 kernel/locking/lockdep.c:3338 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa8/0x210 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2289 console_trylock_spinning kernel/printk/printk.c:1709 [inline] vprintk_emit+0x351/0x960 kernel/printk/printk.c:1977 vprintk_default+0x28/0x30 kernel/printk/printk.c:2005 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2038 start_report mm/kasan/report.c:86 [inline] kasan_report+0xc1/0x15e mm/kasan/report.c:309 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 enqueue_hrtimer+0x1ae/0x570 kernel/time/hrtimer.c:951 __hrtimer_start_range_ns kernel/time/hrtimer.c:1080 [inline] hrtimer_start_range_ns+0x62a/0xda0 kernel/time/hrtimer.c:1106 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] do_nanosleep+0x1a2/0x750 kernel/time/hrtimer.c:1676 hrtimer_nanosleep+0x2e4/0x640 kernel/time/hrtimer.c:1733 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1754 [inline] __x64_sys_nanosleep+0x1e0/0x280 kernel/time/hrtimer.c:1754 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x443ae0 Code: c0 5b 5d c3 66 0f 1f 44 00 00 8b 04 24 48 83 c4 18 5b 5d c3 66 0f 1f 44 00 00 83 3d 11 b5 29 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 74 21 fc ff c3 48 83 ec 08 e8 4a 44 00 00 RSP: 002b:00007ffc84f7ff38 EFLAGS: 00000246 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000000978 RCX: 0000000000443ae0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffc84f7ff40 RBP: 0000000000000978 R08: 0000000000000001 R09: 0000000001e99940 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000976 R13: 0000000000127235 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace 45e69f5e272f25f9 ]--- Code: c0 5b 5d c3 66 0f 1f 44 00 00 8b 04 24 48 83 c4 18 5b 5d c3 66 0f 1f 44 00 00 83 3d 11 b5 29 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 74 21 fc ff c3 48 83 ec 08 e8 4a 44 00 00 RIP: 0010:__read_once_size include/linux/compiler.h:191 [inline] RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline] RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline] RIP: 0010:account_system_index_time+0xe8/0x5f0 kernel/sched/cputime.c:168 RSP: 002b:00007ffc84f7ff38 EFLAGS: 00000246 ORIG_RAX: 0000000000000023 Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d b8 40 01 00 00 48 8d 88 28 01 00 00 48 89 fe 48 c1 ee 03 <0f> b6 14 16 48 89 fe 83 e6 07 40 38 f2 7f 08 84 d2 0f 85 93 03 00 RAX: ffffffffffffffda RBX: 0000000000000978 RCX: 0000000000443ae0 RSP: 0018:ffff8880ae707a80 EFLAGS: 00010006 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffc84f7ff40 RAX: 0000000041b58ab3 RBX: 1ffff11015ce0f54 RCX: 0000000041b58bdb RBP: 0000000000000978 R08: 0000000000000001 R09: 0000000001e99940 RDX: dffffc0000000000 RSI: 000000000836b17e RDI: 0000000041b58bf3 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000976 RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff1335b3d R13: 0000000000127235 R14: 0000000000000000 R15: 0000000000000000 R10: fffffbfff1301b45 R11: ffffffff899ad9e3 R12: ffff8880a94c4440 R13: 000000000077a391 R14: 0000000000000003 R15: ffff8880ae707b20 The buggy address belongs to the page: FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 page:ffffea0002a507c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 flags: 0x1fffc0000000000() CR2: 00000000006d7090 CR3: 0000000096f60000 CR4: 00000000001406e0 raw: 01fffc0000000000 ffffea0002a507c8 ffffea0002a507c8 0000000000000000 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 page dumped because: kasan: bad access detected