INFO: task khugepaged:908 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D22472 908 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 collapse_huge_page+0x2b9/0x2140 mm/khugepaged.c:1006 khugepaged_scan_pmd mm/khugepaged.c:1215 [inline] khugepaged_scan_mm_slot+0x20a1/0x3370 mm/khugepaged.c:1734 khugepaged_do_scan mm/khugepaged.c:1815 [inline] khugepaged+0x9aa/0xce0 mm/khugepaged.c:1860 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 INFO: task rs:main Q:Reg:4404 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. rs:main Q:Reg D23320 4404 1 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 file_start_write include/linux/fs.h:2737 [inline] vfs_write+0x452/0x560 fs/read_write.c:548 ksys_write+0x101/0x260 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+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f9e92ce019d Code: Bad RIP value. RSP: 002b:00007f9e91281000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000008a RCX: 00007f9e92ce019d RDX: 000000000000008a RSI: 0000000000b81a90 RDI: 0000000000000005 RBP: 0000000000b81a90 R08: 206f4e203a363336 R09: 6465767265736572 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f9e91281480 R14: 0000000000000001 R15: 0000000000b81890 INFO: task syz-fuzzer:4523 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D19640 4523 4516 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_pagefault include/linux/fs.h:1583 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 do_page_mkwrite+0x14e/0x520 mm/memory.c:2380 wp_page_shared mm/memory.c:2676 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2776 handle_pte_fault mm/memory.c:3988 [inline] __handle_mm_fault+0x2a84/0x4460 mm/memory.c:4096 handle_mm_fault+0x53e/0xc80 mm/memory.c:4133 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1396 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1471 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160 RIP: 0033:0x70b5e1 Code: Bad RIP value. RSP: 002b:000000c42b6d8820 EFLAGS: 00010212 RAX: 000000c42b6d8b60 RBX: 000000c42b6d8b68 RCX: 00007fa16ad70000 RDX: 0000000000000760 RSI: 0000000000000000 RDI: 0000000000000090 RBP: 000000c42b6d8830 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bf8a R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c42b6d8ce0 INFO: task syz-fuzzer:4533 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D19640 4533 4516 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_pagefault include/linux/fs.h:1583 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 do_page_mkwrite+0x14e/0x520 mm/memory.c:2380 wp_page_shared mm/memory.c:2676 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2776 handle_pte_fault mm/memory.c:3988 [inline] __handle_mm_fault+0x2a84/0x4460 mm/memory.c:4096 handle_mm_fault+0x53e/0xc80 mm/memory.c:4133 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1396 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1471 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160 RIP: 0033:0x70b5e1 Code: Bad RIP value. RSP: 002b:000000c42bab6e80 EFLAGS: 00010212 RAX: 000000c42bab71c0 RBX: 000000c42bab71c8 RCX: 00007fa169b70000 RDX: 0000000000000745 RSI: 0000000000000000 RDI: 0000000000000840 RBP: 000000c42bab6e90 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bf8a R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c42bab7330 INFO: task syz-executor7:4545 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D21232 4545 4537 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_unlinkat+0x2b7/0xa30 fs/namei.c:4055 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: Bad RIP value. RSP: 002b:00007ffec5229068 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffec5229070 RSI: 00007ffec5229100 RDI: 00007ffec5229100 RBP: 00007ffec522ae10 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000202 R12: 000000000282c940 R13: 0000000000000000 R14: 00007ffec522a7e0 R15: 0000000000702140 INFO: task syz-executor3:4546 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21352 4546 4538 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_unlinkat+0x2b7/0xa30 fs/namei.c:4055 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: Bad RIP value. RSP: 002b:00007ffcb95ca5b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffcb95ca5c0 RSI: 00007ffcb95ca650 RDI: 00007ffcb95ca650 RBP: 00007ffcb95cc360 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 0000000002868940 R13: 0000000000000000 R14: 00007ffcb95cbd30 R15: 0000000000702140 INFO: task syz-executor6:4548 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D21232 4548 4540 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_unlinkat+0x2b7/0xa30 fs/namei.c:4055 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: Bad RIP value. RSP: 002b:00007ffc7d77bb78 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffc7d77bb80 RSI: 00007ffc7d77bc10 RDI: 00007ffc7d77bc10 RBP: 00007ffc7d77d920 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 0000000001ed5940 R13: 0000000000000000 R14: 00007ffc7d77d2f0 R15: 0000000000702140 INFO: task syz-executor5:4549 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D21352 4549 4542 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_unlinkat+0x2b7/0xa30 fs/namei.c:4055 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: Bad RIP value. RSP: 002b:00007fffa8dcec38 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007fffa8dcec40 RSI: 00007fffa8dcecd0 RDI: 00007fffa8dcecd0 RBP: 00007fffa8dd09e0 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000202 R12: 000000000260b940 R13: 0000000000000000 R14: 00007fffa8dd03b0 R15: 0000000000702140 INFO: task syz-executor4:10714 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D21232 10714 10713 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_unlinkat+0x2b7/0xa30 fs/namei.c:4055 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: Bad RIP value. RSP: 002b:00007ffdd4e26028 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffdd4e26030 RSI: 00007ffdd4e260c0 RDI: 00007ffdd4e260c0 RBP: 00007ffdd4e27dd0 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 00000000025e9940 R13: 0000000000000000 R14: 00007ffdd4e277a0 R15: 0000000000702140 INFO: task syz-executor2:24132 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #138 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D24152 24132 4550 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_pagefault include/linux/fs.h:1583 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 do_page_mkwrite+0x14e/0x520 mm/memory.c:2380 wp_page_shared mm/memory.c:2676 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2776 handle_pte_fault mm/memory.c:3988 [inline] __handle_mm_fault+0x2a84/0x4460 mm/memory.c:4096 handle_mm_fault+0x53e/0xc80 mm/memory.c:4133 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1396 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1471 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160 RIP: 0033:0x4084b0 Code: 00 00 2e 23 40 00 00 00 00 00 3e 23 40 00 00 00 00 00 4e 23 40 00 00 00 00 00 5e 23 40 00 00 00 00 00 6e 23 40 00 00 00 00 00 <7e> 23 40 00 00 00 00 00 8e 23 40 00 00 00 00 00 9e 23 40 00 00 00 RSP: 002b:00007ffecc198fe0 EFLAGS: 00010283 RAX: 0000001b2f9213c8 RBX: 0000000000000000 RCX: 0000001b30920000 RDX: 0000001b2f9213cc RSI: 0000000000730128 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffecc199020 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bea0 R15: 000000000072bea0 Showing all locks held in the system: 1 lock held by khungtaskd/902: #0: 00000000746f05db (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by khugepaged/908: #0: 000000001b6c0314 (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2b9/0x2140 mm/khugepaged.c:1006 2 locks held by rs:main Q:Reg/4404: #0: 00000000b8093aab (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 0000000002b84d3a (sb_writers#6){++++}, at: file_start_write include/linux/fs.h:2737 [inline] #1: 0000000002b84d3a (sb_writers#6){++++}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4406: 2 locks held by getty/4496: #0: 00000000b6be7b58 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000d6a720a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4497: #0: 000000009607001e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e84b600d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4498: #0: 00000000de0e2c2c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000009eb7baf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4499: #0: 00000000a2fd1166 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004180bbf3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4500: #0: 0000000068b3b2cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000092052b56 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4501: #0: 0000000011a79f22 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000662446b7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4502: #0: 000000008ac30542 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002ff9cab1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-fuzzer/4523: #0: 000000001b6c0314 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000faf626fb (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000faf626fb (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 2 locks held by syz-fuzzer/4533: #0: 000000001b6c0314 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000faf626fb (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000faf626fb (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 1 lock held by syz-executor7/4545: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor3/4546: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor6/4548: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor5/4549: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor4/10714: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 2 locks held by syz-executor2/24132: #0: 0000000019d762b5 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000faf626fb (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000faf626fb (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 2 locks held by syz-executor1/24143: #0: 000000009d1e8739 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000faf626fb (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000faf626fb (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 1 lock held by syz-executor0/24149: #0: 0000000002b84d3a (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000002b84d3a (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 902 Comm: khungtaskd Not tainted 4.18.0-rc4+ #138 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.18.0-rc4+ #138 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_is_watching+0x41/0x150 kernel/rcu/tree.c:1031 Code: 55 41 54 4c 8d a5 78 ff ff ff 53 49 c1 ec 03 4b 8d 04 3c 48 83 ec 68 48 c7 45 80 84 51 bd 88 48 c7 85 78 ff ff ff b3 8a b5 41 <48> c7 45 88 a0 77 66 81 c7 00 f1 f1 f1 f1 c7 40 04 04 f2 f2 f2 65 RSP: 0018:ffff8801daf07308 EFLAGS: 00000092 RAX: ffffed003b5e0e62 RBX: ffffffff892a7480 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000107 RDI: ffff8801d9ae8bb4 RBP: ffff8801daf07398 R08: 00000000000002f3 R09: 0000000000000000 R10: ffffed0043fff009 R11: 0000000000000000 R12: 1ffff1003b5e0e62 R13: ffff8801daf2c9c0 R14: ffff8801daf07370 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000c0f008 CR3: 00000001b16ed000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_sched_held+0x8d/0x120 kernel/rcu/update.c:112 cpufreq_update_util kernel/sched/sched.h:2162 [inline] cfs_rq_util_change kernel/sched/fair.c:3060 [inline] update_cfs_rq_load_avg.part.67+0x253/0x2e0 kernel/sched/fair.c:3745 update_cfs_rq_load_avg kernel/sched/fair.c:3744 [inline] update_blocked_averages+0xac3/0x1770 kernel/sched/fair.c:7663 _nohz_idle_balance+0x5d1/0x820 kernel/sched/fair.c:9642 nohz_idle_balance kernel/sched/fair.c:9695 [inline] run_rebalance_domains+0x2c6/0x4c0 kernel/sched/fair.c:9878 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:408 scheduler_ipi+0x53c/0xa50 kernel/sched/core.c:1800 smp_reschedule_interrupt+0xf5/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:887 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 Code: c7 48 89 45 d8 e8 0a 00 26 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 f9 ff 25 fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffff8801d9af7c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b35ef8a RCX: 0000000000000000 RDX: 1ffffffff11e3610 RSI: 0000000000000001 RDI: ffffffff88f1b080 RBP: ffff8801d9af7c38 R08: ffffed003b5e46d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9af7cf0 R14: ffffffff899ecee0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc7/0x450 arch/x86/kernel/process.c:500 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3aa/0x570 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 start_secondary+0x433/0x5d0 arch/x86/kernel/smpboot.c:270 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242