================================================================== 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-fuzzer/7850 general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 64 Comm: ksoftirqÐP1 Not tainted 5.0.0-rc1+ #17 CPU: 0 PID: 7850 Comm: syz-fuzzer Not tainted 5.0.0-rc1+ #17 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: 00010002 RAX: 00000000a94c9240 RBX: 1ffff11015ce0f54 RCX: 00000000a94c9368 RDX: dffffc0000000000 RSI: 0000000015299270 RDI: 00000000a94c9380 RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff1336415 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 R10: fffffbfff1301b45 R11: ffffffff899b20a3 R12: ffff8880a94ca440 R13: 00000000005426ae R14: 0000000000000003 R15: ffff8880ae707b20 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000068 CR3: 000000009d152000 CR4: 00000000001406e0 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 timerqueue_add+0x2a5/0x320 lib/timerqueue.c:52 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 enqueue_hrtimer+0x1ae/0x570 kernel/time/hrtimer.c:951 Call Trace: __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 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 hrtimer_start_expires include/linux/hrtimer.h:409 [inline] schedule_hrtimeout_range_clock+0x222/0x4c0 kernel/time/hrtimer.c:1935 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 schedule_hrtimeout_range+0x2b/0x40 kernel/time/hrtimer.c:1983 poll_schedule_timeout.constprop.0+0x11a/0x200 fs/select.c:243 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_select+0x15b7/0x1ab0 fs/select.c:601 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 Modules linked in: ====================================================== WARNING: possible circular locking dependency detected 5.0.0-rc1+ #17 Not tainted ------------------------------------------------------ syz-fuzzer/7850 is trying to acquire lock: 000000002157b25e ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 0000000048e7d846 (report_lock){....}, at: start_report mm/kasan/report.c:85 [inline] 0000000048e7d846 (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] schedule_hrtimeout_range_clock+0x222/0x4c0 kernel/time/hrtimer.c:1935 schedule_hrtimeout_range+0x2b/0x40 kernel/time/hrtimer.c:1983 poll_schedule_timeout.constprop.0+0x11a/0x200 fs/select.c:243 do_select+0x15b7/0x1ab0 fs/select.c:601 core_sys_select+0x72a/0xb80 fs/select.c:675 do_pselect fs/select.c:760 [inline] __do_sys_pselect6 fs/select.c:789 [inline] __se_sys_pselect6 fs/select.c:774 [inline] __x64_sys_pselect6+0x41b/0x540 fs/select.c:774 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:10058 sched_fork+0x437/0xb90 kernel/sched/core.c:2359 copy_process+0x1f95/0x8710 kernel/fork.c:1887 _do_fork+0x1a9/0x1170 kernel/fork.c:2227 kernel_thread+0x34/0x40 kernel/fork.c:2286 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+0x778/0x11e0 kernel/printk/printk.c:2426 do_con_write+0x1021/0x2420 drivers/tty/vt/vt.c:2767 con_write+0x27/0xb0 drivers/tty/vt/vt.c:3116 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x497/0x1220 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x45b/0x7a0 drivers/tty/tty_io.c:1043 __vfs_write+0x116/0xb40 fs/read_write.c:485 vfs_write+0x20c/0x580 fs/read_write.c:549 ksys_write+0x105/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 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:2242 console_trylock_spinning kernel/printk/printk.c:1662 [inline] vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 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] schedule_hrtimeout_range_clock+0x222/0x4c0 kernel/time/hrtimer.c:1935 schedule_hrtimeout_range+0x2b/0x40 kernel/time/hrtimer.c:1983 poll_schedule_timeout.constprop.0+0x11a/0x200 fs/select.c:243 do_select+0x15b7/0x1ab0 fs/select.c:601 core_sys_select+0x72a/0xb80 fs/select.c:675 do_pselect fs/select.c:760 [inline] __do_sys_pselect6 fs/select.c:789 [inline] __se_sys_pselect6 fs/select.c:774 [inline] __x64_sys_pselect6+0x41b/0x540 fs/select.c:774 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-fuzzer/7850: #0: 000000000ec92a0a (hrtimer_bases.lock){-.-.}, at: lock_hrtimer_base.isra.0+0x75/0x130 kernel/time/hrtimer.c:165 #1: 0000000048e7d846 (report_lock){....}, at: start_report mm/kasan/report.c:85 [inline] #1: 0000000048e7d846 (report_lock){....}, at: kasan_report+0xb1/0x15e mm/kasan/report.c:309 stack backtrace: CPU: 0 PID: 7850 Comm: syz-fuzzer Not tainted 5.0.0-rc1+ #17 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+0x3014/0x4a30 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:2242 console_trylock_spinning kernel/printk/printk.c:1662 [inline] vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 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] schedule_hrtimeout_range_clock+0x222/0x4c0 kernel/time/hrtimer.c:1935 schedule_hrtimeout_range+0x2b/0x40 kernel/time/hrtimer.c:1983 poll_schedule_timeout.constprop.0+0x11a/0x200 fs/select.c:243 do_select+0x15b7/0x1ab0 fs/select.c:601 core_sys_select+0x72a/0xb80 fs/select.c:675 ? __sanitizer_cov_tra Lost 24 message(s)! ---[ end trace f91b577c3816e9b3 ]--- 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 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 RSP: 0018:ffff8880ae707a80 EFLAGS: 00010002 RAX: 00000000a94c9240 RBX: 1ffff11015ce0f54 RCX: 00000000a94c9368 RDX: dffffc0000000000 RSI: 0000000015299270 RDI: 00000000a94c9380 RBP: ffff8880ae707b48 R08: ffff8880ae71f5f0 R09: fffffbfff1336415 R10: fffffbfff1301b45 R11: ffffffff899b20a3 R12: ffff8880a94ca440 R13: 00000000005426ae R14: 0000000000000003 R15: ffff8880ae707b20 core_sys_select+0x72a/0xb80 fs/select.c:675 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000068 CR3: 000000009d152000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400