bisecting fixing commit since b850307b279cbd12ab8c654d1a3dfe55319cc475 building syzkaller on d88894e6773ab63ac8b3f4b2edbae88290aaf0d6 testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.1.0 kernel signature: 3673e59173ec6cb9d0f9258df24b20edf711082b3346cf528d9aee38f67aca36 run #0: crashed: INFO: task hung in __get_super run #1: crashed: INFO: task hung in __get_super run #2: crashed: INFO: task hung in __get_super run #3: crashed: INFO: task hung in __get_super run #4: crashed: INFO: task hung in __get_super run #5: crashed: INFO: task hung in __get_super run #6: crashed: INFO: task hung in __get_super run #7: crashed: INFO: task hung in __get_super run #8: crashed: INFO: task hung in __get_super run #9: crashed: INFO: task hung in __blkdev_get testing current HEAD 6a24ca2506d64598eac5d5219e99acca9bde4ca5 testing commit 6a24ca2506d64598eac5d5219e99acca9bde4ca5 with gcc (GCC) 8.1.0 kernel signature: e51abacec65d28a0e3a135c69666186e2a1f3188a4fb2caec6acaf9dcc22c503 all runs: crashed: INFO: task hung in __get_super revisions tested: 2, total time: 38m25.272882522s (build: 19m12.605797294s, test: 17m54.620223129s) the crash still happens on HEAD commit msg: Linux 4.14.194 crash: INFO: task hung in __get_super IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.2:7746 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27696 7746 6456 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1fb/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 __get_super.part.2+0x198/0x260 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x23/0x30 fs/super.c:707 fsync_bdev+0x13/0xb0 fs/block_dev.c:495 invalidate_partition+0x1f/0x40 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xac/0x8c0 block/partition-generic.c:515 __blkdev_reread_part+0x12a/0x190 block/ioctl.c:173 blkdev_reread_part+0x20/0x40 block/ioctl.c:193 loop_reread_partitions+0x5d/0x70 drivers/block/loop.c:624 loop_set_status+0xb04/0x1070 drivers/block/loop.c:1193 loop_set_status64+0x83/0xc0 drivers/block/loop.c:1311 lo_ioctl+0x53e/0x1c20 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 block_ioctl+0xd7/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c0a7 RSP: 002b:00007fb362c519f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb362c526d4 RCX: 000000000045c0a7 RDX: 00007fb362c51ab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000003 R13: 00007ffce64850df R14: 0000000000000004 R15: 000000000078bf0c INFO: task systemd-udevd:7762 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28344 7762 3640 0x00000104 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 blkdev_put+0x25/0x480 fs/block_dev.c:1816 blkdev_close+0x88/0xd0 fs/block_dev.c:1865 __fput+0x232/0x740 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x14a/0x190 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f7fe9a79270 RSP: 002b:00007ffe25855778 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000000000f RCX: 00007f7fe9a79270 RDX: 00007f7fe9a63b58 RSI: 0000000000000000 RDI: 000000000000000f RBP: 00007f7fea932710 R08: 9b14aef5949a29c6 R09: 0000000000000007 R10: 0000000000000116 R11: 0000000000000246 R12: 0000000000000002 R13: 0000000000000000 R14: 00005614d1df0c30 R15: 000000000000000f INFO: task syz-executor.1:7789 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28216 7789 6461 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1fb/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 __get_super.part.2+0x198/0x260 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x23/0x30 fs/super.c:707 fsync_bdev+0x13/0xb0 fs/block_dev.c:495 invalidate_partition+0x1f/0x40 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xac/0x8c0 block/partition-generic.c:515 __blkdev_reread_part+0x12a/0x190 block/ioctl.c:173 blkdev_reread_part+0x20/0x40 block/ioctl.c:193 loop_reread_partitions+0x5d/0x70 drivers/block/loop.c:624 loop_set_status+0xb04/0x1070 drivers/block/loop.c:1193 loop_set_status64+0x83/0xc0 drivers/block/loop.c:1311 lo_ioctl+0x53e/0x1c20 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 block_ioctl+0xd7/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c0a7 RSP: 002b:00007f43f75ba9f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f43f75bb6d4 RCX: 000000000045c0a7 RDX: 00007f43f75baab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000003 R13: 00007fffe517a9df R14: 0000000000000004 R15: 000000000078bf0c INFO: task syz-executor.1:7798 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28352 7798 6461 0x80000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 ioctl_by_bdev+0x95/0x110 fs/block_dev.c:2068 isofs_get_last_session fs/isofs/inode.c:571 [inline] isofs_fill_super+0x187b/0x2690 fs/isofs/inode.c:670 mount_bdev+0x26f/0x330 fs/super.c:1134 isofs_mount+0x10/0x20 fs/isofs/inode.c:1570 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c1d9 RSP: 002b:00007f43f7599c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000001fa40 RCX: 000000000045c1d9 RDX: 0000000020000080 RSI: 0000000020000200 RDI: 0000000020000340 RBP: 000000000078bff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 00007fffe517a9df R14: 00007f43f759a9c0 R15: 000000000078bfac INFO: task systemd-udevd:7788 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28184 7788 3640 0x00000104 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 blkdev_get+0x265/0x890 fs/block_dev.c:1611 blkdev_open+0x19f/0x200 fs/block_dev.c:1772 do_dentry_open+0x3e4/0xde0 fs/open.c:777 vfs_open+0xfc/0x240 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb73/0x27a0 fs/namei.c:3569 do_filp_open+0x16b/0x220 fs/namei.c:3603 do_sys_open+0x1c2/0x340 fs/open.c:1081 SYSC_open fs/open.c:1099 [inline] SyS_open+0x19/0x20 fs/open.c:1094 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f7fe9a79840 RSP: 002b:00007ffe25859fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00005614d1df8900 RCX: 00007f7fe9a79840 RDX: 00005614d005afe3 RSI: 00000000000a0800 RDI: 00005614d1df5140 RBP: 00007ffe2585a150 R08: 00005614d005a670 R09: 0000000000000010 R10: 00005614d005ad0c R11: 0000000000000246 R12: 00007ffe2585a0a0 R13: 00005614d1df3870 R14: 0000000000000003 R15: 000000000000000e INFO: task syz-executor.4:7821 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28672 7821 6465 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1fb/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 __get_super.part.2+0x198/0x260 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x23/0x30 fs/super.c:707 fsync_bdev+0x13/0xb0 fs/block_dev.c:495 invalidate_partition+0x1f/0x40 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xac/0x8c0 block/partition-generic.c:515 __blkdev_reread_part+0x12a/0x190 block/ioctl.c:173 blkdev_reread_part+0x20/0x40 block/ioctl.c:193 loop_reread_partitions+0x5d/0x70 drivers/block/loop.c:624 loop_set_status+0xb04/0x1070 drivers/block/loop.c:1193 loop_set_status64+0x83/0xc0 drivers/block/loop.c:1311 lo_ioctl+0x53e/0x1c20 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 block_ioctl+0xd7/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c0a7 RSP: 002b:00007f0014ede9f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0014edf6d4 RCX: 000000000045c0a7 RDX: 00007f0014edeab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000003 R13: 00007ffe2f6aae0f R14: 0000000000000004 R15: 000000000078bf0c INFO: task syz-executor.4:7830 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28952 7830 6465 0x80000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 ioctl_by_bdev+0x95/0x110 fs/block_dev.c:2068 isofs_get_last_session fs/isofs/inode.c:571 [inline] isofs_fill_super+0x187b/0x2690 fs/isofs/inode.c:670 mount_bdev+0x26f/0x330 fs/super.c:1134 isofs_mount+0x10/0x20 fs/isofs/inode.c:1570 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c1d9 RSP: 002b:00007f0014ebdc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000001fa40 RCX: 000000000045c1d9 RDX: 0000000020000080 RSI: 0000000020000200 RDI: 0000000020000340 RBP: 000000000078bff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 00007ffe2f6aae0f R14: 00007f0014ebe9c0 R15: 000000000078bfac INFO: task syz-executor.4:7891 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28904 7891 6465 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 blkdev_get+0x265/0x890 fs/block_dev.c:1611 blkdev_open+0x19f/0x200 fs/block_dev.c:1772 do_dentry_open+0x3e4/0xde0 fs/open.c:777 vfs_open+0xfc/0x240 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb73/0x27a0 fs/namei.c:3569 do_filp_open+0x16b/0x220 fs/namei.c:3603 do_sys_open+0x1c2/0x340 fs/open.c:1081 SYSC_open fs/open.c:1099 [inline] SyS_open+0x19/0x20 fs/open.c:1094 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007f0014e9c9f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f0014e9d6d4 RCX: 0000000000415f51 RDX: 00007f0014e9cbaa RSI: 0000000000000002 RDI: 00007f0014e9cba0 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000003 R13: 00007ffe2f6aae0f R14: 00007f0014e9d9c0 R15: 000000000078c04c INFO: task syz-executor.4:7892 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29384 7892 6465 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 blkdev_get+0x417/0x890 fs/block_dev.c:1611 blkdev_get_by_path+0x71/0xb0 fs/block_dev.c:1692 mount_bdev+0x43/0x330 fs/super.c:1092 isofs_mount+0x10/0x20 fs/isofs/inode.c:1570 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c1d9 RSP: 002b:00007f0014e7bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000001fa40 RCX: 000000000045c1d9 RDX: 0000000020000080 RSI: 0000000020000200 RDI: 0000000020000340 RBP: 000000000078c130 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0ec R13: 00007ffe2f6aae0f R14: 00007f0014e7c9c0 R15: 000000000078c0ec INFO: task syz-executor.0:7849 blocked for more than 140 seconds. Not tainted 4.14.194-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28408 7849 6459 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1fb/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 __get_super.part.2+0x198/0x260 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x23/0x30 fs/super.c:707 fsync_bdev+0x13/0xb0 fs/block_dev.c:495 invalidate_partition+0x1f/0x40 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xac/0x8c0 block/partition-generic.c:515 __blkdev_reread_part+0x12a/0x190 block/ioctl.c:173 blkdev_reread_part+0x20/0x40 block/ioctl.c:193 loop_reread_partitions+0x5d/0x70 drivers/block/loop.c:624 loop_clr_fd+0x7ff/0xab0 drivers/block/loop.c:1078 lo_ioctl+0x7da/0x1c20 drivers/block/loop.c:1424 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x7c0/0x1760 block/ioctl.c:594 block_ioctl+0xd7/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c0a7 RSP: 002b:00007fcebef2f9f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcebef306d4 RCX: 000000000045c0a7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000004 R15: 000000000078bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4548 3 locks held by syz-executor.2/7746: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 1 lock held by systemd-udevd/7762: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x25/0x480 fs/block_dev.c:1816 3 locks held by syz-executor.1/7789: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 2 locks held by syz-executor.1/7798: #0: (&type->s_umount_key#58/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#58/1){+.+.}, at: [] sget_userns+0x429/0xb40 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 1 lock held by systemd-udevd/7788: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 3 locks held by syz-executor.4/7821: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 2 locks held by syz-executor.4/7830: #0: (&type->s_umount_key#58/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#58/1){+.+.}, at: [] sget_userns+0x429/0xb40 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 1 lock held by syz-executor.4/7891: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 1 lock held by syz-executor.4/7892: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 3 locks held by syz-executor.0/7849: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 2 locks held by syz-executor.0/7859: #0: (&type->s_umount_key#58/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#58/1){+.+.}, at: [] sget_userns+0x429/0xb40 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 1 lock held by syz-executor.0/7893: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 1 lock held by syz-executor.0/7894: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 3 locks held by syz-executor.3/7870: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 2 locks held by syz-executor.3/7879: #0: (&type->s_umount_key#58/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#58/1){+.+.}, at: [] sget_userns+0x429/0xb40 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 1 lock held by syz-executor.3/7895: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 1 lock held by syz-executor.3/7896: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 1 lock held by systemd-udevd/7869: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 3 locks held by syz-executor.5/7885: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#59){.+.+}, at: [] __get_super.part.2+0x198/0x260 fs/super.c:678 2 locks held by syz-executor.5/7890: #0: (&type->s_umount_key#58/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#58/1){+.+.}, at: [] sget_userns+0x429/0xb40 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8a/0x1c20 drivers/block/loop.c:1414 1 lock held by syz-executor.5/7897: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 1 lock held by syz-executor.5/7898: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x185/0xff0 fs/block_dev.c:1455 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 4.14.194-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x119 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x51b/0xa70 kernel/hung_task.c:274 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2353 Comm: kworker/u4:4 Not tainted 4.14.194-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet task: ffff8880a147c0c0 task.stack: ffff8880a1b48000 RIP: 0010:validate_chain kernel/locking/lockdep.c:2471 [inline] RIP: 0010:__lock_acquire+0x960/0x42d0 kernel/locking/lockdep.c:3491 RSP: 0018:ffff8880a1b4f9d0 EFLAGS: 00000802 RAX: dffffc0000000000 RBX: 000000005ba5813c RCX: ffff8880a147c948 RDX: 0000000000000004 RSI: ffff8880a147c9c0 RDI: ffff8880a147c9e1 RBP: ffff8880a1b4fba0 R08: ffff8880a147c9e0 R09: 0000000000000000 R10: 0000000000000078 R11: ffff8880a147c0c0 R12: 00000000bb1a0351 R13: 00000000956e8eb7 R14: cf0f3f3150889208 R15: ffff8880a147c9c0 FS: 0000000000000000(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc335f3c000 CR3: 000000009476b000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x17e/0x3e0 kernel/locking/lockdep.c:3998 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:629 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:931 [inline] batadv_iv_ogm_schedule_buff+0x3f1/0xdd0 net/batman-adv/bat_iv_ogm.c:997 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1041 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x545/0x7c0 net/batman-adv/bat_iv_ogm.c:1859 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 47 20 25 00 80 04 00 3d 00 00 04 00 0f 84 ff 01 00 00 48 c7 c2 00 e4 33 88 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 <48> c7 c0 00 e4 33 88 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85