NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task systemd-udevd:3644 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D25760 3644 1 0x00000104 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_release+0x1b/0x190 drivers/block/loop.c:1677 __blkdev_put+0x4ec/0x6a0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 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+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fedd0b61270 RSP: 002b:00007fff3f6fd8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007fff3f6fd980 RCX: 00007fedd0b61270 RDX: 0000000000000000 RSI: 000000000000125f RDI: 000000000000000e RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff3f6fda90 R13: 0000564a380d4a60 R14: 0000564a381872d0 R15: 00007fff3f6fd960 INFO: task syz-executor.1:6349 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25568 6349 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x307/0x10c0 fs/block_dev.c:1472 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416900 RSP: 002b:00007fff09974e48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000041577 RCX: 0000000000416900 RDX: 00007fff09974eda RSI: 0000000000000002 RDI: 00007fff09974ed0 RBP: 0000000000000234 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff09974e80 R14: 00000000000414ef R15: 00007fff09974e90 INFO: task syz-executor.5:6350 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24528 6350 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x307/0x10c0 fs/block_dev.c:1472 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416900 RSP: 002b:00007ffe5b65f4b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000041635 RCX: 0000000000416900 RDX: 00007ffe5b65f54a RSI: 0000000000000002 RDI: 00007ffe5b65f540 RBP: 000000000000023b R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe5b65f4f0 R14: 00000000000414a5 R15: 00007ffe5b65f500 INFO: task syz-executor.2:6353 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25584 6353 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x307/0x10c0 fs/block_dev.c:1472 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416900 RSP: 002b:00007ffdbca23bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000004157e RCX: 0000000000416900 RDX: 00007ffdbca23c8a RSI: 0000000000000002 RDI: 00007ffdbca23c80 RBP: 0000000000000233 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdbca23c30 R14: 00000000000413c4 R15: 00007ffdbca23c40 INFO: task syz-executor.4:6354 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25568 6354 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x307/0x10c0 fs/block_dev.c:1472 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416900 RSP: 002b:00007ffd377b4b98 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000041500 RCX: 0000000000416900 RDX: 00007ffd377b4c2a RSI: 0000000000000002 RDI: 00007ffd377b4c20 RBP: 0000000000000263 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd377b4bd0 R14: 00000000000414a2 R15: 00007ffd377b4be0 INFO: task syz-executor.0:13037 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27520 13037 6351 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:624 loop_clr_fd+0x828/0xac0 drivers/block/loop.c:1078 lo_ioctl+0x89c/0x1c00 drivers/block/loop.c:1424 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17c0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c9f7 RSP: 002b:00007fb8695079d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045c9f7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 0000000000000009 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000c6c R14: 00000000004c1c55 R15: 00007fb8695086d4 INFO: task syz-executor.0:13056 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29392 13056 6351 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416921 RSP: 002b:00007fb8694e69d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000050b1a0 RCX: 0000000000416921 RDX: 00007fb8694e6bba RSI: 0000000000000002 RDI: 00007fb8694e6bb0 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c6c R14: 00000000004c1c55 R15: 00007fb8694e76d4 INFO: task syz-executor.3:13049 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28720 13049 6352 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 loop_control_ioctl+0x15b/0x2d0 drivers/block/loop.c:2007 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cb29 RSP: 002b:00007fe8fd513c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e96e0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000401 R14: 00000000004c6c83 R15: 00007fe8fd5146d4 INFO: task syz-executor.3:13051 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29744 13051 6352 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cb29 RSP: 002b:00007fe8fd4f2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e96a0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000400 R14: 00000000004c6c6b R15: 00007fe8fd4f36d4 INFO: task syz-executor.3:13054 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D30096 13054 6352 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cb29 RSP: 002b:00007fe8fd4d1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e96e0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000006 RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000401 R14: 00000000004c6c83 R15: 00007fe8fd4d26d4 Showing all locks held in the system: 1 lock held by khungtaskd/1058: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by systemd-udevd/3644: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0x9e/0x6a0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1b/0x190 drivers/block/loop.c:1677 1 lock held by in:imklog/5966: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by syz-executor.1/6349: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.5/6350: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.2/6353: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.4/6354: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.0/13037: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c00 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.0/13056: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x192/0x10c0 fs/block_dev.c:1457 2 locks held by syz-executor.3/13049: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993 #1: (&lo->lo_ctl_mutex){+.+.}, at: [] loop_control_ioctl+0x15b/0x2d0 drivers/block/loop.c:2007 1 lock held by syz-executor.3/13051: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993 1 lock held by syz-executor.3/13054: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1058 Comm: khungtaskd Not tainted 4.14.184-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+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 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: 8959 Comm: kworker/u4:6 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff888057ce6240 task.stack: ffff88804b1a8000 RIP: 0010:batadv_nc_purge_paths+0xe0/0x320 net/batman-adv/network-coding.c:451 RSP: 0018:ffff88804b1afca0 EFLAGS: 00000246 RAX: 1ffff11010c23810 RBX: ffff88808611c080 RCX: ffff888057ce6ac8 RDX: 1ffff1100b3f6a42 RSI: ffff888057ce6b18 RDI: ffff888059fb5204 RBP: 0000000000000000 R08: 000000000000245b R09: ffffffff89e67c58 R10: ffff888057ce6b18 R11: ffff888057ce6240 R12: dffffc0000000000 R13: ffffffff86266f10 R14: ffff888059fb5200 R15: ffff888059f79780 FS: 0000000000000000(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa6bb586000 CR3: 000000009458b000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: batadv_nc_worker+0x26a/0x6d0 net/batman-adv/network-coding.c:729 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 00 48 8b 04 24 4d 6b f6 38 4c 03 70 08 4c 89 f7 e8 b5 ef 17 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 0f 85 c5 01 00 00 48 8b 2b 23 e8 a9 43 34 fb e8 f4 c0 dc fe 85 c0 0f 85 72 74 00 00 e8