INFO: task syz-executor.2:27876 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26728 27876 7210 0x80004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 rwsem_down_write_slowpath+0x7d0/0xd60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x125/0x130 kernel/locking/rwsem.c:1532 rdma_dev_exit_net+0x4a/0x300 drivers/infiniband/core/device.c:1060 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 ops_exit_list net/core/net_namespace.c:186 [inline] setup_net+0x5a2/0x770 net/core/net_namespace.c:364 copy_net_ns+0x339/0x540 net/core/net_namespace.c:482 create_new_namespaces+0x52e/0x9f0 kernel/nsproxy.c:108 copy_namespaces+0x2f6/0x370 kernel/nsproxy.c:177 copy_process+0x203b/0x52f0 kernel/fork.c:2088 _do_fork+0x134/0x650 kernel/fork.c:2430 __might_fault+0xf5/0x150 mm/memory.c:4814 __do_sys_clone kernel/fork.c:2585 [inline] __se_sys_clone kernel/fork.c:2566 [inline] __x64_sys_clone+0x21c/0x260 kernel/fork.c:2566 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1136: #0: ffffffff892e85d0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:858 1 lock held by khugepaged/1147: 1 lock held by in:imklog/6659: #0: ffff88809f1bb8f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 3 locks held by kworker/u4:6/6742: #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline] #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241 #1: ffffc90003237d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 #2: ffffffff895ac230 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:565 6 locks held by syz-executor.5/27784: 2 locks held by syz-executor.2/27876: #0: ffffffff895ac230 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x31d/0x540 net/core/net_namespace.c:478 #1: ffffffff89558020 (rdma_nets_rwsem){++++}-{3:3}, at: rdma_dev_exit_net+0x4a/0x300 drivers/infiniband/core/device.c:1060 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1136 Comm: khungtaskd Not tainted 5.7.0-rc2-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 533 Comm: kworker/u4:4 Not tainted 5.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:754 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:776 [inline] RIP: 0010:lock_release+0x8b/0x760 kernel/locking/lockdep.c:4948 Code: b9 2b 89 48 c1 e8 03 42 80 3c 28 00 74 0c 48 c7 c7 a8 b9 2b 89 e8 d5 8d 58 00 48 83 3d b5 07 d3 07 00 0f 84 9f 06 00 00 9c 58 <0f> 1f 44 00 00 49 89 c4 48 c7 c0 b8 b9 2b 89 48 c1 e8 03 42 80 3c RSP: 0018:ffffc90002687bf0 EFLAGS: 00000286 RAX: 0000000000000286 RBX: 1ffff110150e9d60 RCX: ffff8880a874e240 RDX: 0000000000000000 RSI: ffffffff87ef3355 RDI: ffffffff892e85d0 RBP: ffff8880a874e240 R08: dffffc0000000000 R09: ffffed1015d07074 R10: ffffed1015d07074 R11: 0000000000000000 R12: ffff8880a1a90c00 R13: dffffc0000000000 R14: ffff888095e67000 R15: ffff8880a874eb04 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005646d018c0a8 CR3: 0000000204a7c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled+0x40/0x240 lib/smp_processor_id.c:16 rcu_lock_release+0x5/0x20 include/linux/rcupdate.h:212 rcu_read_unlock include/linux/rcupdate.h:655 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x261/0x5e0 net/batman-adv/network-coding.c:718 lock_is_held include/linux/lockdep.h:406 [inline] rcu_read_lock_sched_held+0x106/0x170 kernel/rcu/update.c:121 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352