bisecting fixing commit since a1b977b49b66c75e6c51a515f6700371ae720217 building syzkaller on fc7735a27949755327024847e12dcc1b868bcb99 testing commit a1b977b49b66c75e6c51a515f6700371ae720217 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d296a253abff005e5134ca56258e9b28e1d876331bdee7dc49bc633c9bff32c3 all runs: crashed: INFO: task hung in sync_inodes_sb testing current HEAD 4938296e03bd227e5020d63d418956fe52baf97c testing commit 4938296e03bd227e5020d63d418956fe52baf97c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 41eadbc916ec13dfb9f6701ded521335d40b2e25bbff9585b6c927020c7506f7 all runs: crashed: INFO: task hung in sync_inodes_sb revisions tested: 2, total time: 40m11.569771677s (build: 25m27.455123549s, test: 14m4.558370139s) the crash still happens on HEAD commit msg: Linux 4.19.198 crash: INFO: task hung in sync_inodes_sb Bluetooth: hci3: command 0x0406 tx timeout Bluetooth: hci0: command 0x0406 tx timeout Bluetooth: hci1: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout Bluetooth: hci4: command 0x0406 tx timeout INFO: task syz-executor.2:5930 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D23224 5930 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007ffd8ec9e868 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffd8ec9e939 RSI: 0000000000000002 RDI: 00007ffd8ec9e930 RBP: 00007ffd8ec9e930 R08: 00000000ffffffff R09: 00007ffd8ec9e700 R10: 00000000029c58e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffd8ec9f9e0 R14: 00000000029c5810 R15: 0000000000000002 INFO: task syz-executor.3:5932 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D23800 5932 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007fffb8b047c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007fffb8b04899 RSI: 0000000000000002 RDI: 00007fffb8b04890 RBP: 00007fffb8b04890 R08: 00000000ffffffff R09: 00007fffb8b04660 R10: 0000000001b638e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007fffb8b05940 R14: 0000000001b63810 R15: 0000000000000002 INFO: task syz-executor.4:5934 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D23816 5934 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007ffd2084f918 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffd2084f9e9 RSI: 0000000000000002 RDI: 00007ffd2084f9e0 RBP: 00007ffd2084f9e0 R08: 00000000ffffffff R09: 00007ffd2084f7b0 R10: 000000000232c8e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffd20850a90 R14: 000000000232c810 R15: 0000000000000002 INFO: task syz-executor.5:5936 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D23752 5936 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007ffc7ad9a388 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffc7ad9a459 RSI: 0000000000000002 RDI: 00007ffc7ad9a450 RBP: 00007ffc7ad9a450 R08: 00000000ffffffff R09: 00007ffc7ad9a220 R10: 000000000177a8e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffc7ad9b500 R14: 000000000177a810 R15: 0000000000000002 INFO: task syz-executor.0:5938 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D23864 5938 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007ffee77d4b58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffee77d4c29 RSI: 0000000000000002 RDI: 00007ffee77d4c20 RBP: 00007ffee77d4c20 R08: 00000000ffffffff R09: 00007ffee77d49f0 R10: 00000000030578e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffee77d5cd0 R14: 0000000003057810 R15: 0000000000000002 INFO: task syz-executor.1:5939 blocked for more than 140 seconds. Not tainted 4.19.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D23736 5939 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 wb_wait_for_completion+0x14f/0x1c0 fs/fs-writeback.c:222 sync_inodes_sb+0x183/0x8e0 fs/fs-writeback.c:2459 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x114/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466ca7 Code: Bad RIP value. RSP: 002b:00007ffff18341a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffff1834279 RSI: 0000000000000002 RDI: 00007ffff1834270 RBP: 00007ffff1834270 R08: 00000000ffffffff R09: 00007ffff1834040 R10: 00000000018ca8e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffff1835320 R14: 00000000018ca810 R15: 0000000000000002 Showing all locks held in the system: 2 locks held by kworker/u4:0/7: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 00000000aee240da ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 2 locks held by kworker/u4:2/48: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 0000000077a4841a ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 1 lock held by khungtaskd/1100: #0: 00000000c5dfdf05 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4443 2 locks held by kworker/u4:4/2372: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000009b2d3a93 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 2 locks held by kworker/u4:5/5780: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000005a773c76 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 2 locks held by syz-executor.2/5930: #0: 00000000838ee562 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 00000000838ee562 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 00000000ccaea408 (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000ccaea408 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by syz-executor.3/5932: #0: 0000000058aa2ce5 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 0000000058aa2ce5 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 00000000dbadd51e (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000dbadd51e (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by syz-executor.4/5934: #0: 00000000bc1e0088 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 00000000bc1e0088 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 0000000013273c56 (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 0000000013273c56 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by syz-executor.5/5936: #0: 00000000adb9f12b (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 00000000adb9f12b (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 000000003236b374 (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 000000003236b374 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/5938: #0: 000000000ddc2ff4 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 000000000ddc2ff4 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 0000000092c3664f (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 0000000092c3664f (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by syz-executor.1/5939: #0: 00000000f9e9917a (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:359 [inline] #0: 00000000f9e9917a (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x137/0x160 fs/super.c:356 #1: 00000000ffcb8d7d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000ffcb8d7d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x16a/0x8e0 fs/fs-writeback.c:2457 2 locks held by kworker/u4:7/7287: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000006f446440 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 2 locks held by kworker/u4:9/7300: #0: 0000000075e6c01e ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 00000000c0f6787a ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1100 Comm: khungtaskd Not tainted 4.19.198-syzkaller #0 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+0x17c/0x226 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x120 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: kworker/u4:1 Not tainted 4.19.198-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs+0x49/0xb0 kernel/rcu/tree.c:350 Code: ff df 89 c0 48 8d 3c c5 00 2f 51 88 48 89 f9 48 c1 e9 03 80 3c 11 00 75 5d 48 03 1c c5 00 2f 51 88 be 04 00 00 00 4c 8d 63 10 <4c> 89 e7 e8 0f 51 3f 00 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 RSP: 0018:ffff8881f4d1fcd8 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffff8881f67239c0 RCX: 1ffffffff10a25e1 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffffff88512f08 RBP: ffff8881f4d1fcf0 R08: ffffed103ece473b R09: ffffed103ece473a R10: ffffed103ece473a R11: ffff8881f67239d3 R12: ffff8881f67239d0 R13: 0000000000000351 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f033df0a000 CR3: 000000000866d005 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:1025 rcu_read_unlock include/linux/rcupdate.h:677 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:423 [inline] batadv_nc_worker+0x3a9/0x630 net/batman-adv/network-coding.c:730 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415