bisecting fixing commit since ef244c3088856cf048c77231653b4c92a7b2213c building syzkaller on a41ca8fa8285754d8561dcc3ed54cca2da60eed7 testing commit ef244c3088856cf048c77231653b4c92a7b2213c with gcc (GCC) 8.1.0 kernel signature: 2507e0b5b0e9600bfa3e096ba877a0690d65b4be864ca998882a889aa8bad960 run #0: basic kernel testing failed: timed out run #1: crashed: INFO: rcu detected stall in sys_open run #2: crashed: INFO: rcu detected stall in sys_open run #3: crashed: INFO: rcu detected stall in sys_open run #4: crashed: INFO: rcu detected stall in ext4_file_read_iter run #5: crashed: INFO: rcu detected stall in sys_open 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 sys_open run #9: crashed: INFO: rcu detected stall in sys_open testing current HEAD 033c4ea49a4ba7a2b13aabf3ec755557924a9cda testing commit 033c4ea49a4ba7a2b13aabf3ec755557924a9cda with gcc (GCC) 8.1.0 kernel signature: 2709a315e411e40fae96b1b05a9bf0c26621336fb9635e891bcc927e8db59535 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 sys_open run #3: crashed: INFO: rcu detected stall in sys_open run #4: crashed: INFO: rcu detected stall in sys_open run #5: crashed: INFO: rcu detected stall in sys_open run #6: crashed: INFO: rcu detected stall in corrupted run #7: crashed: INFO: rcu detected stall in ext4_file_read_iter run #8: crashed: INFO: rcu detected stall in sys_open run #9: crashed: INFO: rcu detected stall in corrupted revisions tested: 2, total time: 32m56.480127359s (build: 18m40.539995948s, test: 13m6.073561514s) the crash still happens on HEAD commit msg: Linux 4.19.122 crash: INFO: rcu detected stall in corrupted audit: type=1800 audit(1589273043.400:35): pid=7360 uid=0 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed comm="syz-executor.1" name="bus" dev="sda1" ino=15800 res=0 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=6489, q=170) rcu: INFO: rcu_sched detected stalls on CPUs/tasks: rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294964193-4294953690), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: (detected by 1, t=10502 jiffies, g=-999, q=0) syz-executor.3 R running task 24536 7383 6346 0x80000000 rcu: All QSes seen, last rcu_sched kthread activity 10502 (4294964193-4294953691), jiffies_till_next_fqs=1, root ->qsmask 0x0 Call Trace: syz-executor.2 R running task 24536 7386 6342 0x80000000 Call Trace: sched_show_task.cold.86+0x2ee/0x35d kernel/sched/core.c:5338 sched_show_task.cold.86+0x2ee/0x35d kernel/sched/core.c:5338 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold.81+0xa80/0xd67 kernel/rcu/tree.c:2682 update_process_times+0x2a/0x60 kernel/time/timer.c:1638 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold.81+0xa80/0xd67 kernel/rcu/tree.c:2682 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:168 update_process_times+0x2a/0x60 kernel/time/timer.c:1638 tick_sched_timer+0x37/0xf0 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2f7/0xab0 kernel/time/hrtimer.c:1463 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:168 tick_sched_timer+0x37/0xf0 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2f7/0xab0 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x114/0x540 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x114/0x540 arch/x86/kernel/apic/apic.c:1092 RIP: 0010:loop3+0x339/0x37d apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 Code: f8 01 f0 48 83 c7 40 48 81 ff 00 02 00 00 0f 82 dd fc ff ff 48 8b bc 24 10 02 00 00 48 8b b4 24 08 02 00 00 48 83 c6 40 03 07 <89> 07 03 5f 04 89 5f 04 03 4f 08 89 4f 08 44 03 47 0c 44 89 47 0c RSP: 0018:ffff88808cd57220 EFLAGS: 00000203 ORIG_RAX: ffffffffffffff13 RIP: 0010:loop2+0x1f4/0x39e RAX: 0000000004446bbc RBX: 00000000ab849357 RCX: 0000000038a4d04b Code: e2 0d 41 31 cf c4 63 7b f0 f2 16 89 d6 45 31 e6 c4 63 7b f0 e2 02 44 03 44 3c 20 44 09 d6 45 31 e6 41 89 d4 44 21 ce 45 21 d4 <45> 01 ef 45 01 c3 44 09 e6 45 01 f0 45 01 fb 45 01 f8 41 89 c7 c4 RDX: 000000005a30f5a6 RSI: ffff88808b05f5c0 RDI: ffff88808cd57570 RSP: 0018:ffff88808d0cf220 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RBP: ffff88808cd574b0 R08: 00000000d67ddb83 R09: 00000000ec902ad9 RAX: 00000000bd97dce3 RBX: 000000005b9d5266 RCX: 0000000031e2ae42 R10: 00000000f81ee2ba R11: 00000000f3b13be6 R12: 0000000082049303 R13: 00000000749abe58 R14: 000000006211265f R15: 000000006fcbf216 RDX: 00000000a7b35f14 RSI: 00000000f101531d RDI: 0000000000000180 RBP: ffff88808d0cf4b0 R08: 00000000833e1500 R09: 00000000f10173fd R10: 000000005442460b R11: 00000000715b3ae4 R12: 0000000004024600 R13: 00000000d96f9c56 R14: 000000001c35b8c1 R15: 0000000019f57262 sha256_avx2_update+0x10/0x20 arch/x86/crypto/sha256_ssse3_glue.c:235 crypto_shash_update+0xd0/0x2e0 crypto/shash.c:126 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:373 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:393 [inline] ima_calc_file_hash+0x511/0x7f0 security/integrity/ima/ima_crypto.c:458 sha256_avx2_update+0x10/0x20 arch/x86/crypto/sha256_ssse3_glue.c:235 crypto_shash_update+0xd0/0x2e0 crypto/shash.c:126 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:373 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:393 [inline] ima_calc_file_hash+0x511/0x7f0 security/integrity/ima/ima_crypto.c:458 ima_collect_measurement+0x3fc/0x520 security/integrity/ima/ima_api.c:231 ima_collect_measurement+0x3fc/0x520 security/integrity/ima/ima_api.c:231 process_measurement+0xb0e/0x14b0 security/integrity/ima/ima_main.c:284 process_measurement+0xb0e/0x14b0 security/integrity/ima/ima_main.c:284 ima_file_check+0xc8/0x110 security/integrity/ima/ima_main.c:391 ima_file_check+0xc8/0x110 security/integrity/ima/ima_main.c:391 do_last fs/namei.c:3425 [inline] path_openat+0x746/0x3c60 fs/namei.c:3537 do_last fs/namei.c:3425 [inline] path_openat+0x746/0x3c60 fs/namei.c:3537 do_filp_open+0x177/0x250 fs/namei.c:3567 do_filp_open+0x177/0x250 fs/namei.c:3567 do_sys_open+0x1dd/0x350 fs/open.c:1085 do_sys_open+0x1dd/0x350 fs/open.c:1085 __do_sys_open fs/open.c:1103 [inline] __se_sys_open fs/open.c:1098 [inline] __x64_sys_open+0x79/0xb0 fs/open.c:1098 __do_sys_open fs/open.c:1103 [inline] __se_sys_open fs/open.c:1098 [inline] __x64_sys_open+0x79/0xb0 fs/open.c:1098 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459f49 RIP: 0033:0x459f49 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f848b7e0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RSP: 002b:00007f25dc788c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 0000000000000000 RSI: 0000000000141042 RDI: 0000000020000100 RDX: 0000000000000000 RSI: 0000000000141042 RDI: 0000000020000100 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f25dc7896d4 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f848b7e16d4 R13: 00000000004fa77f R14: 00000000004dc190 R15: 00000000ffffffff R13: 00000000004fa77f R14: 00000000004dc190 R15: 00000000ffffffff rcu: rcu_sched kthread starved for 10502 jiffies! g-999 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: rcu_preempt kthread starved for 10503 jiffies! g6489 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_sched R running task 30064 11 2 0x80000000 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29208 10 2 0x80000000 Call Trace: Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 context_switch kernel/sched/core.c:2826 [inline] __schedule+0x78c/0x1c10 kernel/sched/core.c:3515 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule+0x7f/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x3ab/0xda0 kernel/time/timer.c:1806 schedule_timeout+0x3ab/0xda0 kernel/time/timer.c:1806 rcu_gp_kthread+0xce6/0x23d0 kernel/rcu/tree.c:2202 rcu_gp_kthread+0xce6/0x23d0 kernel/rcu/tree.c:2202 kthread+0x324/0x3e0 kernel/kthread.c:246 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 sched: RT throttling activated