bisecting cause commit starting from 2187f215ebaac73ddbd814696d7c7fa34f0c3de0 building syzkaller on 79b211f74b08737aeb4934c6ff69a263b3c38013 testing commit 2187f215ebaac73ddbd814696d7c7fa34f0c3de0 with gcc (GCC) 8.1.0 kernel signature: 1ac50d829bc2d04431d97720985f6109ccb4cd10 run #0: crashed: INFO: rcu detected stall in __do_page_fault run #1: crashed: INFO: rcu detected stall in bad_area run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in bad_area run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in do_signal run #7: crashed: INFO: rcu detected stall in do_signal run #8: crashed: INFO: rcu detected stall in corrupted run #9: crashed: INFO: rcu detected stall in bad_area testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: 5753a572ab95cfe182707ab4f0cfae938d52ca1d run #0: crashed: INFO: rcu detected stall in bad_area run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in corrupted run #5: crashed: INFO: rcu detected stall in exit_to_usermode_loop run #6: crashed: INFO: rcu detected stall in do_signal run #7: crashed: INFO: rcu detected stall in do_signal run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: no output from test machine testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 78927ecfc579ea39e1453499a04cc2bd84d9e93f run #0: crashed: INFO: rcu detected stall in bad_area run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: INFO: rcu detected stall in do_signal run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in corrupted run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: INFO: rcu detected stall in do_signal testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 3999d87b1213d397f1f005fa2bf0d6bb1856def4 run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in bad_area run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in __do_page_fault run #7: crashed: INFO: rcu detected stall in do_signal run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: INFO: rcu detected stall in do_signal testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: b47adc44eed16783634a19ef46bfa0342e55e905 run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in corrupted run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in corrupted run #5: crashed: INFO: rcu detected stall in do_signal run #6: crashed: INFO: rcu detected stall in bad_area run #7: crashed: INFO: rcu detected stall in do_signal run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: no output from test machine testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: c127afb82011333c67e175eeae34e1f5157c572b run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in find_vma run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in __do_page_fault run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in do_signal run #7: crashed: INFO: rcu detected stall in do_signal run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: INFO: rcu detected stall in bad_area testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: 7faa6981cd21898a03295a82ab24de00bd6b2d38 run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in find_vma run #2: crashed: INFO: rcu detected stall in corrupted run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in bad_area run #7: crashed: INFO: rcu detected stall in bad_area run #8: crashed: INFO: rcu detected stall in bad_area run #9: crashed: BUG: workqueue lockup testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: e405bef66d2d069fc6ee206216a95df4a8cc516e run #0: crashed: INFO: rcu detected stall in __do_page_fault run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in corrupted run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: INFO: rcu detected stall in do_signal testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: 1c40d93d530ad73958f76bd96da606c58af1a10c run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in bad_area run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in do_signal run #7: crashed: INFO: rcu detected stall in corrupted run #8: crashed: INFO: rcu detected stall in bad_area run #9: crashed: INFO: rcu detected stall in corrupted testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 1c8df4f938fc58a911015bb52b0b767372dd5274 run #0: crashed: INFO: rcu detected stall in bad_area run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in bad_area run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in corrupted run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in bad_area run #8: crashed: INFO: rcu detected stall in do_signal run #9: crashed: INFO: rcu detected stall in bad_area testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 6d7add99972769c1b9264d078cd241af11b3e08d run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in bad_area run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in do_signal run #7: crashed: INFO: rcu detected stall in bad_area run #8: crashed: INFO: rcu detected stall in bad_area run #9: crashed: INFO: rcu detected stall in bad_area testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: fdc63be08e23a27928d8a2de53d04651d11f3e63 run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: BUG: workqueue lockup run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: 077a4d4bcc0c314d9fa408755181b0832447848d run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in corrupted run #3: crashed: INFO: rcu detected stall in do_signal run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: 22108b9361107d8bec7017a414a6c1cbc6110673 run #0: crashed: INFO: rcu detected stall in bad_area run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: no output from test machine run #3: crashed: no output from test machine run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 89033b307254c81f0d55ae0daca3dd5885c90a92 run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in bad_area run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in bad_area run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in corrupted run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 kernel signature: baa2931815e91dccb3ed1092c6ee459d6fd27e6d run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in corrupted run #5: crashed: BUG: workqueue lockup run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 kernel signature: 3edf372e2890fde9f04659b82b19d29e717fe47f run #0: crashed: INFO: rcu detected stall in do_signal run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: no output from test machine run #5: crashed: no output from test machine run #6: crashed: no output from test machine run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 844f5d6ee8f28bcdb252cd258fd96d23f7bfc767 run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in corrupted run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in corrupted run #5: crashed: INFO: rcu detected stall in corrupted run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in corrupted run #8: crashed: INFO: rcu detected stall in corrupted run #9: crashed: no output from test machine testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: 965f5348f1c534aaf4f188c1c995b98b12f95e37 run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in do_signal run #2: crashed: INFO: rcu detected stall in do_signal run #3: crashed: INFO: rcu detected stall in bad_area run #4: crashed: INFO: rcu detected stall in do_signal run #5: crashed: INFO: rcu detected stall in corrupted run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: no output from test machine run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 599e56a5913b56cce5f048cf3a447ec1da8b95c7 run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in corrupted run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in corrupted run #5: crashed: INFO: rcu detected stall in bad_area run #6: crashed: INFO: rcu detected stall in bad_area run #7: crashed: BUG: workqueue lockup run #8: crashed: no output from test machine run #9: crashed: no output from test machine testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: aead602f030a06cd37f65f4714ba4d6125291225 run #0: crashed: INFO: rcu detected stall in corrupted run #1: crashed: INFO: rcu detected stall in corrupted run #2: crashed: INFO: rcu detected stall in bad_area run #3: crashed: INFO: rcu detected stall in corrupted run #4: crashed: INFO: rcu detected stall in bad_area run #5: crashed: INFO: rcu detected stall in corrupted run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in bad_area run #8: crashed: INFO: rcu detected stall in corrupted run #9: crashed: INFO: rcu detected stall in bad_area revisions tested: 21, total time: 4h12m37.892140323s (build: 1h45m11.146486714s, test: 2h24m51.038729679s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: INFO: rcu detected stall in bad_area IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready hrtimer: interrupt took 53762 ns INFO: rcu_sched detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=-99, c=-100, q=1) All QSes seen, last rcu_sched kthread activity 10498 (4294954487-4294943989), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 28256 7748 7475 0x00000004 0000000000001d33 ffff88012c007ca8 ffffffff813d414c ffffffff81615a00 0000000041b58ab3 ffffffff868f20bf ffffffff813d3ec0 ffff88012c007c68 ffffffff81491fd4 0000000000000000 ffffffff87651000 0000000000000002 Call Trace: [] sched_show_task+0x28c/0x400 kernel/sched/core.c:4976 [] print_other_cpu_stall kernel/rcu/tree.c:1317 [inline] [] check_cpu_stall kernel/rcu/tree.c:1423 [inline] [] __rcu_pending kernel/rcu/tree.c:3883 [inline] [] rcu_pending kernel/rcu/tree.c:3947 [inline] [] rcu_check_callbacks+0x1c5c/0x2010 kernel/rcu/tree.c:2772 [] update_process_times+0x34/0x60 kernel/time/timer.c:1420 [] tick_sched_handle.isra.19+0x44/0xe0 kernel/time/tick-sched.c:151 [] tick_sched_timer+0x64/0xd0 kernel/time/tick-sched.c:1178 [] __run_hrtimer kernel/time/hrtimer.c:1242 [inline] [] __hrtimer_run_queues+0x2d4/0xbf0 kernel/time/hrtimer.c:1306 [] hrtimer_interrupt+0x19d/0x470 kernel/time/hrtimer.c:1340 [] local_apic_timer_interrupt+0x6e/0xf0 arch/x86/kernel/apic/apic.c:907 [] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:931 [] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:621 [] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:791 [inline] [] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline] [] ? _raw_spin_unlock_irqrestore+0x97/0xd0 kernel/locking/spinlock.c:191 [] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline] [] force_sig_info+0x1f5/0x2a0 kernel/signal.c:1180 [] force_sig_info_fault.constprop.30+0x194/0x290 arch/x86/mm/fault.c:244 [] __bad_area_nosemaphore+0x228/0x410 arch/x86/mm/fault.c:868 [] __bad_area arch/x86/mm/fault.c:898 [inline] [] bad_area+0x64/0x80 arch/x86/mm/fault.c:904 [] __do_page_fault+0x6f4/0x9e0 arch/x86/mm/fault.c:1331 [] do_page_fault+0x4a/0x60 arch/x86/mm/fault.c:1414 [] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:917 rcu_sched kthread starved for 10498 jiffies! g18446744073709551517 c18446744073709551516 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 rcu_sched R running task 29392 8 2 0x00000000 ffff88012b07fac8 ffff88012c120400 ffff88012c120d90 ffff88012c120d68 ffff88012c120418 ffff88012b0701c8 1ffff10000000000 ffff88012b05a180 ffff88012b0701c0 ffff88012b078000 ffffed002560f001 ffff88012b078008 Call Trace: [] schedule+0x9a/0x1c0 kernel/sched/core.c:3250 [] schedule_timeout+0x2e5/0x670 kernel/time/timer.c:1531 [] rcu_gp_kthread+0xee2/0x1f70 kernel/rcu/tree.c:2126 [] kthread+0x209/0x2d0 kernel/kthread.c:209 [] ret_from_fork+0x22/0x50 arch/x86/entry/entry_64.S:392 sched: RT throttling activated INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10538 jiffies, g=2069, c=2068, q=104) All QSes seen, last rcu_preempt kthread activity 10537 (4294954526-4294943989), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 28256 7748 7475 0x0000000c 0000000000001d33 ffff88012c007ca8 ffffffff813d414c ffffffff81615a00 0000000041b58ab3 ffffffff868f20bf ffffffff813d3ec0 ffff88012c007c68 ffffffff81491fd4 0000000000000000 ffffffff87651000 0000000000000002 Call Trace: [] sched_show_task+0x28c/0x400 kernel/sched/core.c:4976 [] print_other_cpu_stall kernel/rcu/tree.c:1317 [inline] [] check_cpu_stall kernel/rcu/tree.c:1423 [inline] [] __rcu_pending kernel/rcu/tree.c:3883 [inline] [] rcu_pending kernel/rcu/tree.c:3947 [inline] [] rcu_check_callbacks+0x1c5c/0x2010 kernel/rcu/tree.c:2772 [] update_process_times+0x34/0x60 kernel/time/timer.c:1420 [] tick_sched_handle.isra.19+0x44/0xe0 kernel/time/tick-sched.c:151 [] tick_sched_timer+0x64/0xd0 kernel/time/tick-sched.c:1178 [] __run_hrtimer kernel/time/hrtimer.c:1242 [inline] [] __hrtimer_run_queues+0x2d4/0xbf0 kernel/time/hrtimer.c:1306 [] hrtimer_interrupt+0x19d/0x470 kernel/time/hrtimer.c:1340 [] local_apic_timer_interrupt+0x6e/0xf0 arch/x86/kernel/apic/apic.c:907 [] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:931 [] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:621 [] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:791 [inline] [] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline] [] ? _raw_spin_unlock_irqrestore+0x97/0xd0 kernel/locking/spinlock.c:191 [] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline] [] force_sig_info+0x1f5/0x2a0 kernel/signal.c:1180 [] force_sig_info_fault.constprop.30+0x194/0x290 arch/x86/mm/fault.c:244 [] __bad_area_nosemaphore+0x228/0x410 arch/x86/mm/fault.c:868 [] __bad_area arch/x86/mm/fault.c:898 [inline] [] bad_area+0x64/0x80 arch/x86/mm/fault.c:904 [] __do_page_fault+0x6f4/0x9e0 arch/x86/mm/fault.c:1331 [] do_page_fault+0x4a/0x60 arch/x86/mm/fault.c:1414 [] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:917 rcu_preempt kthread starved for 10537 jiffies! g2069 c2068 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 rcu_preempt R running task 29392 7 2 0x00000000 ffff88012b06fac8 ffff88012c120400 ffff88012c120d90 ffff88012c120d68 ffff88012c120418 ffff88012b05a188 1ffff10000000000 ffff880129d64400 ffff88012b05a180 ffff88012b068000 ffffed002560d001 ffff88012b068008 Call Trace: [] schedule+0x9a/0x1c0 kernel/sched/core.c:3250 [] schedule_timeout+0x2e5/0x670 kernel/time/timer.c:1531 [] rcu_gp_kthread+0xee2/0x1f70 kernel/rcu/tree.c:2126 [] kthread+0x209/0x2d0 kernel/kthread.c:209 [] ret_from_fork+0x22/0x50 arch/x86/entry/entry_64.S:392