Hi Chuck, Is this a known issue? [ 5087.845704] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 5087.848463] #PF error: [normal kernel read fault] [ 5087.849852] PGD 0 P4D 0 [ 5087.850618] Oops: 0000 [#1] SMP PTI [ 5087.851577] CPU: 0 PID: 5964 Comm: NFSv4 callback Not tainted 5.0.0-rc7+ #1 [ 5087.853388] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 5087.860280] RIP: 0010:trace_event_raw_event_xprt_enq_xmit+0x6f/0xf0 [sunrpc] [ 5087.862149] Code: 00 00 00 48 89 ee 48 89 e7 e8 7d 69 65 ef 48 85 c0 74 4a 41 0f b7 94 24 e0 00 00 00 48 89 e7 89 50 08 49 8b 94 24 a8 00 00 00 <8b> 52 04 89 50 0c 49 8b 94 24 c0 00 00 00 8b 92 a8 00 00 00 0f ca [ 5087.866380] RSP: 0018:ffffc03c43297cf8 EFLAGS: 00010286 [ 5087.867797] RAX: ffff9ef936d134a0 RBX: 0000000000000003 RCX: 0000000000000000 [ 5087.869456] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc03c43297cf8 [ 5087.871092] RBP: ffff9ef92f5b28f0 R08: 0000000000000246 R09: 0000000000000000 [ 5087.872767] R10: fffff11380b706c0 R11: 0000000000000000 R12: ffff9ef9338bda00 [ 5087.874659] R13: 0000000000000004 R14: ffff9ef932e813f0 R15: ffff9ef932e81000 [ 5087.876538] FS: 0000000000000000(0000) GS:ffff9ef93bc00000(0000) knlGS:0000000000000000 [ 5087.879404] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5087.881202] CR2: 0000000000000004 CR3: 000000000f0f2002 CR4: 00000000001606f0 [ 5087.883331] Call Trace: [ 5087.885770] xprt_request_enqueue_transmit+0x2b6/0x4a0 [sunrpc] [ 5087.887341] ? rpc_task_need_encode+0x40/0x40 [sunrpc] [ 5087.888710] call_bc_transmit+0xd5/0x170 [sunrpc] [ 5087.889880] __rpc_execute+0x7e/0x3f0 [sunrpc] [ 5087.891022] rpc_run_bc_task+0x78/0xd0 [sunrpc] [ 5087.892097] bc_svc_process+0x281/0x340 [sunrpc] [ 5087.895456] nfs41_callback_svc+0x130/0x1c0 [nfsv4] [ 5087.897018] ? remove_wait_queue+0x60/0x60 [ 5087.898038] kthread+0xf5/0x130 [ 5087.899531] ? nfs_callback_authenticate+0x50/0x50 [nfsv4] [ 5087.900912] ? kthread_bind+0x10/0x10 [ 5087.902438] ret_from_fork+0x1f/0x30
