INFO: task khugepaged:907 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D22472 907 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 INFO: task syz-fuzzer:4514 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D20400 4514 4508 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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:6125 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: 48 89 6c 24 10 48 8d 6c 24 10 48 8b 44 24 20 48 8b 48 08 48 8b 50 10 48 8d 58 08 48 83 fa 08 0f 8c 1e 01 00 00 48 8b 54 24 28 <88> 11 48 8b 48 08 48 8b 70 10 48 83 fe 01 0f 86 44 01 00 00 48 89 RSP: 002b:000000c421dbb130 EFLAGS: 00010212 RAX: 000000c421dbb878 RBX: 000000c421dbb880 RCX: 00007f365dc66000 RDX: fffffffffffffffe RSI: 0000000001168198 RDI: 000000c421dbb140 RBP: 000000c421dbb140 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bb32 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c421dbba00 INFO: task syz-fuzzer:4522 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D18968 4522 4508 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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:6125 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: 48 89 6c 24 10 48 8d 6c 24 10 48 8b 44 24 20 48 8b 48 08 48 8b 50 10 48 8d 58 08 48 83 fa 08 0f 8c 1e 01 00 00 48 8b 54 24 28 <88> 11 48 8b 48 08 48 8b 70 10 48 83 fe 01 0f 86 44 01 00 00 48 89 RSP: 002b:000000c421d1d240 EFLAGS: 00010212 RAX: 000000c421d1d878 RBX: 000000c421d1d880 RCX: 00007f365ca66000 RDX: fffffffffffffffe RSI: 0000000002091e98 RDI: 000000c421d1d250 RBP: 000000c421d1d250 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bb32 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c421d1d9e8 INFO: task syz-executor3:4536 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21232 4536 4528 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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: c0 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 8d 7e 20 40 80 10 73 64 48 83 fa 02 7e c2 0f b6 54 0b 01 8d 7a 80 40 80 ff 3f RSP: 002b:00007ffc83ac3308 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffc83ac3310 RSI: 00007ffc83ac33a0 RDI: 00007ffc83ac33a0 RBP: 00007ffc83ac50b0 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000a R11: 0000000000000202 R12: 0000000002766940 R13: 0000000000000000 R14: 00007ffc83ac4a80 R15: 0000000000702140 INFO: task syz-executor1:4537 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D21232 4537 4530 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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: c0 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 8d 7e 20 40 80 10 73 64 48 83 fa 02 7e c2 0f b6 54 0b 01 8d 7a 80 40 80 ff 3f RSP: 002b:00007ffc9386b588 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffc9386b590 RSI: 00007ffc9386b620 RDI: 00007ffc9386b620 RBP: 00007ffc9386d330 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 000000000134d940 R13: 0000000000000000 R14: 00007ffc9386cd00 R15: 0000000000702140 INFO: task syz-executor0:4538 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D19928 4538 4529 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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: c0 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 8d 7e 20 40 80 10 73 64 48 83 fa 02 7e c2 0f b6 54 0b 01 8d 7a 80 40 80 ff 3f RSP: 002b:00007ffcb2238ab8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffcb2238ac0 RSI: 00007ffcb2238b50 RDI: 00007ffcb2238b50 RBP: 00007ffcb223a860 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000206 R12: 0000000000ea0940 R13: 0000000000000000 R14: 00007ffcb223a230 R15: 0000000000702140 INFO: task syz-executor5:4540 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D21352 4540 4531 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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 filename_create+0x13e/0x5b0 fs/namei.c:3640 user_path_create fs/namei.c:3703 [inline] do_mkdirat+0xda/0x310 fs/namei.c:3842 __do_sys_mkdir fs/namei.c:3866 [inline] __se_sys_mkdir fs/namei.c:3864 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3864 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455267 Code: 00 00 48 8b 4c 24 78 8b 44 01 04 89 44 24 08 48 8b 84 24 c8 00 00 00 48 89 04 24 e8 53 e7 ff ff 48 8b 44 24 10 48 89 84 24 d0 <00> 00 00 48 8b 8c 24 f8 00 00 00 48 8b 54 24 78 8b 4c 0a 04 89 4c RSP: 002b:00007ffef190b958 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffef190b980 RCX: 0000000000455267 RDX: 00007ffef190c635 RSI: 00000000000001ff RDI: 00007ffef190c630 RBP: 0000000000000013 R08: 0000000000000000 R09: 0000000000000005 R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000001380 R14: 00007ffef190c000 R15: 00000000007034c0 INFO: task syz-executor4:23414 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24696 23414 4541 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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:6125 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: 24 1f e9 d2 00 00 00 48 ff c2 48 83 fa 08 0f 83 ad 00 00 00 84 01 0f b6 1c 11 38 d8 75 e9 48 89 54 24 20 48 8b 5c 24 48 0f b6 <73> 50 48 0f af f2 0f b6 5b 51 48 89 cf 48 8d 74 3e 08 84 db 74 7c RSP: 002b:00007ffd2c694320 EFLAGS: 00010287 RAX: 0000001b2f0213e4 RBX: 0000000000000000 RCX: 0000001b30020000 RDX: 0000001b2f0213e8 RSI: 0000000000730128 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffd2c694360 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bea0 R15: 000000000072bea0 INFO: task syz-executor7:23418 blocked for more than 140 seconds. Not tainted 4.18.0-rc3+ #7 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D20136 23418 4542 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 __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 filename_create+0x13e/0x5b0 fs/namei.c:3640 user_path_create fs/namei.c:3703 [inline] do_symlinkat+0xfe/0x2d0 fs/namei.c:4157 __do_sys_symlink fs/namei.c:4183 [inline] __se_sys_symlink fs/namei.c:4181 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4181 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b57 Code: 80 80 fa 3f 77 10 83 e6 1f c1 e6 06 83 e1 3f 09 ce 83 fe 7f 7f 19 c7 44 24 28 fd ff 00 00 48 ff c0 48 89 44 24 30 48 8b 2c 24 <48> 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 RSP: 002b:00007ffd0d84caf8 EFLAGS: 00000217 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000455b57 RDX: 0000000000000000 RSI: 00000000004bb371 RDI: 00007ffd0d84d7f0 RBP: 0000000000000013 R08: 0000000000000000 R09: 0000000000b4a940 R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd0d84d1a0 R15: 00000000007034c0 Showing all locks held in the system: 1 lock held by khungtaskd/901: #0: 00000000b519c3e6 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by khugepaged/907: #0: 0000000078dd9871 (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2b9/0x2140 mm/khugepaged.c:1006 2 locks held by rs:main Q:Reg/4397: #0: 0000000059b79b4a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000002eac28b9 (sb_writers#6){++++}, at: file_start_write include/linux/fs.h:2737 [inline] #1: 000000002eac28b9 (sb_writers#6){++++}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4399: #0: 000000004f1387d0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4489: #0: 000000006380f575 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001a604442 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4490: #0: 0000000029d97601 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000dcc05dda (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4491: #0: 0000000024804816 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b626c750 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4492: #0: 00000000fbb5581d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005c4de341 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4493: #0: 000000007f5a7f40 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008b4cacac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4494: #0: 00000000692439b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003ac809b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4495: #0: 000000000687a1a7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000403605b3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-fuzzer/4514: #0: 0000000078dd9871 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6125 2 locks held by syz-fuzzer/4522: #0: 0000000078dd9871 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6125 1 lock held by syz-executor3/4536: #0: 000000002eac28b9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000002eac28b9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor1/4537: #0: 000000002eac28b9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000002eac28b9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor0/4538: #0: 000000002eac28b9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000002eac28b9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor5/4540: #0: 000000002eac28b9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000002eac28b9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 2 locks held by syz-executor4/23414: #0: 0000000049213abb (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 arch/x86/mm/fault.c:1325 #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: sb_start_pagefault include/linux/fs.h:1583 [inline] #1: 00000000eacd7ad8 (sb_pagefaults){++++}, at: ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6125 1 lock held by syz-executor7/23418: #0: 000000002eac28b9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000002eac28b9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc3+ #7 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:240 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 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54