INFO: task khugepaged:908 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "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 syz-fuzzer:4540 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D20304 4540 4534 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:000000c42b2c6810 EFLAGS: 00010212 RAX: 000000c42b2c7068 RBX: 000000c42b2c7070 RCX: 00007f6f3b093000 RDX: fffffffffffffffe RSI: 000000c4201b4038 RDI: 000000c42b2c6820 RBP: 000000c42b2c6820 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bb32 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c423e170e0 INFO: task syz-fuzzer:4551 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D20400 4551 4534 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:000000c42b40aa78 EFLAGS: 00010212 RAX: 000000c42b40b0b0 RBX: 000000c42b40b0b8 RCX: 00007f6f3d493000 RDX: fffffffffffffffe RSI: 0000000002098b58 RDI: 000000c42b40aa88 RBP: 000000c42b40aa88 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bb32 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c42b40b220 INFO: task syz-executor1:4561 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D21736 4561 4554 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:00007ffc42de5548 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffc42de5550 RSI: 00007ffc42de55e0 RDI: 00007ffc42de55e0 RBP: 00007ffc42de72f0 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000206 R12: 0000000001a0c940 R13: 0000000000000000 R14: 00007ffc42de6cc0 R15: 0000000000702140 INFO: task syz-executor0:4562 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D21912 4562 4553 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:00007ffd34d67668 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffd34d67670 RSI: 00007ffd34d67700 RDI: 00007ffd34d67700 RBP: 00007ffd34d69410 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000202 R12: 0000000001d87940 R13: 0000000000000000 R14: 00007ffd34d68de0 R15: 0000000000702140 INFO: task syz-executor2:4564 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D21232 4564 4555 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:00007ffdea822fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffdea822ff0 RSI: 00007ffdea823080 RDI: 00007ffdea823080 RBP: 00007ffdea824d90 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000206 R12: 0000000000f90940 R13: 0000000000000000 R14: 00007ffdea824760 R15: 0000000000702140 INFO: task syz-executor4:4567 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D22032 4567 4558 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:00007ffe56104f68 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffe56104f70 RSI: 00007ffe56105000 RDI: 00007ffe56105000 RBP: 00007ffe56106d10 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000202 R12: 00000000022f3940 R13: 0000000000000000 R14: 00007ffe561066e0 R15: 0000000000702140 INFO: task syz-executor6:4568 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D21232 4568 4560 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:00007fffa2c45cb8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007fffa2c45cc0 RSI: 00007fffa2c45d50 RDI: 00007fffa2c45d50 RBP: 00007fffa2c47a60 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000206 R12: 000000000188c940 R13: 0000000000000000 R14: 00007fffa2c47430 R15: 0000000000702140 INFO: task syz-executor7:10377 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D24696 10377 4566 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:00007fff524e7570 EFLAGS: 00010287 RAX: 0000001b30823c5c RBX: 0000000000000000 RCX: 0000001b31820000 RDX: 0000001b30823c60 RSI: 000000000000001a RDI: 000000000000001a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fff524e75b0 R11: 0000000000000246 R12: 000000000000006f R13: 0000000000000002 R14: 000000000072bea0 R15: 000000000072bea0 INFO: task syz-executor3:10408 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #142 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D24696 10408 4563 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:00007ffce7b17170 EFLAGS: 00010287 RAX: 0000001b30922d90 RBX: 0000000000000000 RCX: 0000001b31920000 RDX: 0000001b30922d94 RSI: 00000000007302f8 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffce7b171b0 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bea0 R15: 000000000072bea0 Showing all locks held in the system: 1 lock held by khungtaskd/902: #0: 00000000efccf1ae (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by khugepaged/908: #0: 00000000272f85fc (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2b9/0x2140 mm/khugepaged.c:1006 2 locks held by rs:main Q:Reg/4420: #0: 00000000e2525704 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000c93a831c (sb_writers#6){++++}, at: file_start_write include/linux/fs.h:2737 [inline] #1: 00000000c93a831c (sb_writers#6){++++}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4422: #0: 00000000c359bf60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4512: #0: 00000000579e71b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e44af2d7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4513: #0: 00000000426783e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b2f363fe (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4514: #0: 00000000f18251ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000009f61f13f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4515: #0: 00000000d525aadf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000eb49bfe7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4516: #0: 000000005a206d6a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000027571f38 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4517: #0: 000000006e1512da (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000141e5a13 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4518: #0: 0000000052a13973 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000091200f11 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-fuzzer/4540: #0: 00000000272f85fc (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 000000003e66cea1 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 000000003e66cea1 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 2 locks held by syz-fuzzer/4551: #0: 00000000272f85fc (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 000000003e66cea1 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 000000003e66cea1 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 1 lock held by syz-executor1/4561: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor0/4562: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor2/4564: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor4/4567: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor6/4568: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 2 locks held by syz-executor7/10377: #0: 00000000719be8b2 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 000000003e66cea1 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 000000003e66cea1 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 2 locks held by syz-executor3/10408: #0: 00000000f341144b (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 000000003e66cea1 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 000000003e66cea1 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6126 1 lock held by syz-executor5/10411: #0: 00000000c93a831c (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000c93a831c (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 902 Comm: khungtaskd Not tainted 4.18.0-rc4+ #142 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54