INFO: task syz-executor.5:16427 blocked for more than 140 seconds. Not tainted 4.19.118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28832 16427 6925 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:72 prealloc_memcg_shrinker mm/vmscan.c:194 [inline] prealloc_shrinker+0x16f/0x340 mm/vmscan.c:382 alloc_super fs/super.c:265 [inline] sget_userns+0x773/0xcd0 fs/super.c:519 mount_ns+0x8e/0x1d0 fs/super.c:1068 mount_fs+0xa3/0x30c fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x400 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] kern_mount_data+0x55/0xd0 fs/namespace.c:3255 mq_init_ns+0x162/0x220 ipc/mqueue.c:1548 create_ipc_ns ipc/namespace.c:58 [inline] copy_ipcs+0x258/0x410 ipc/namespace.c:84 create_new_namespaces+0x212/0x7c0 kernel/nsproxy.c:87 copy_namespaces+0x325/0x3c0 kernel/nsproxy.c:165 copy_process.part.0+0x39ad/0x7a50 kernel/fork.c:1900 copy_process kernel/fork.c:1694 [inline] _do_fork+0x22f/0xf40 kernel/fork.c:2207 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4b662b2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00000000004da840 RCX: 000000000045c829 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 000080218a081fff RBP: 000000000078bf00 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000076 R14: 00000000004c311e R15: 00007f4b662b36d4 INFO: task syz-executor.5:16435 blocked for more than 140 seconds. Not tainted 4.19.118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29104 16435 6925 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:72 prealloc_memcg_shrinker mm/vmscan.c:194 [inline] prealloc_shrinker+0x16f/0x340 mm/vmscan.c:382 alloc_super fs/super.c:265 [inline] sget_userns+0x773/0xcd0 fs/super.c:519 mount_ns+0x8e/0x1d0 fs/super.c:1068 mount_fs+0xa3/0x30c fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x400 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] kern_mount_data+0x55/0xd0 fs/namespace.c:3255 mq_init_ns+0x162/0x220 ipc/mqueue.c:1548 create_ipc_ns ipc/namespace.c:58 [inline] copy_ipcs+0x258/0x410 ipc/namespace.c:84 create_new_namespaces+0x212/0x7c0 kernel/nsproxy.c:87 copy_namespaces+0x325/0x3c0 kernel/nsproxy.c:165 copy_process.part.0+0x39ad/0x7a50 kernel/fork.c:1900 copy_process kernel/fork.c:1694 [inline] _do_fork+0x22f/0xf40 kernel/fork.c:2207 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4b66270c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00000000004da840 RCX: 000000000045c829 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 000080218a081fff RBP: 000000000078c040 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000076 R14: 00000000004c311e R15: 00007f4b662716d4 Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000030af0a5 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 3 locks held by khugepaged/1086: 1 lock held by in:imklog/6126: #0: 00000000dd13fc9b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by syz-executor.5/16427: #0: 0000000036fc1572 (&type->s_umount_key#18/1){+.+.}, at: alloc_super fs/super.c:226 [inline] #0: 0000000036fc1572 (&type->s_umount_key#18/1){+.+.}, at: sget_userns+0x1fc/0xcd0 fs/super.c:519 #1: 000000000e2f2c15 (shrinker_rwsem){++++}, at: prealloc_memcg_shrinker mm/vmscan.c:194 [inline] #1: 000000000e2f2c15 (shrinker_rwsem){++++}, at: prealloc_shrinker+0x16f/0x340 mm/vmscan.c:382 2 locks held by syz-executor.5/16435: #0: 000000005db7b49d (&type->s_umount_key#18/1){+.+.}, at: alloc_super fs/super.c:226 [inline] #0: 000000005db7b49d (&type->s_umount_key#18/1){+.+.}, at: sget_userns+0x1fc/0xcd0 fs/super.c:519 #1: 000000000e2f2c15 (shrinker_rwsem){++++}, at: prealloc_memcg_shrinker mm/vmscan.c:194 [inline] #1: 000000000e2f2c15 (shrinker_rwsem){++++}, at: prealloc_shrinker+0x16f/0x340 mm/vmscan.c:382 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.118-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 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: 7136 Comm: kworker/u4:4 Not tainted 4.19.118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x24a/0x49c0 kernel/locking/lockdep.c:3321 Code: 00 be 04 00 00 00 44 89 84 24 80 00 00 00 48 89 84 24 88 00 00 00 e8 a5 16 4e 00 48 8b 84 24 88 00 00 00 f0 ff 80 38 01 00 00 <49> 8d b6 80 08 00 00 44 8b 84 24 80 00 00 00 48 ba 00 00 00 00 00 RSP: 0000:ffff888218ad7a20 EFLAGS: 00000012 RAX: ffffffff8b474c30 RBX: 0000000000000000 RCX: ffffffff814f545b RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8b474d68 RBP: ffff888218ad7be8 R08: 0000000000000001 R09: fffffbfff168e9ae R10: fffffbfff168e9ad R11: ffffffff8b474d6b R12: 0000000000000000 R13: 0000000000000000 R14: ffff888212eaa6c0 R15: ffff888048b86920 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c427ad1fe0 CR3: 000000005e080000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3907 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] batadv_nc_purge_paths+0xdf/0x3b0 net/batman-adv/network-coding.c:453 batadv_nc_worker+0x299/0x760 net/batman-adv/network-coding.c:731 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155 worker_thread+0x96/0xe20 kernel/workqueue.c:2298 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415