From: Olga Kornievskaia <kolga@xxxxxxxxxx> Backchannel doesn't have the rq_task->tk_clientid pointer set. Otherwise can lead to the following oops: ocalhost login: [ 111.385319] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 111.388073] #PF error: [normal kernel read fault] [ 111.389452] PGD 80000000290d8067 P4D 80000000290d8067 PUD 75f25067 PMD 0 [ 111.391224] Oops: 0000 [#1] SMP PTI [ 111.392151] CPU: 0 PID: 3533 Comm: NFSv4 callback Not tainted 5.0.0-rc7+ #1 [ 111.393787] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 111.396340] RIP: 0010:trace_event_raw_event_xprt_enq_xmit+0x6f/0xf0 [sunrpc] [ 111.397974] Code: 00 00 00 48 89 ee 48 89 e7 e8 bd 0a 85 d7 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 [ 111.402215] RSP: 0018:ffffb98743263cf8 EFLAGS: 00010286 [ 111.403406] RAX: ffffa0890fc3bc88 RBX: 0000000000000003 RCX: 0000000000000000 [ 111.405057] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffb98743263cf8 [ 111.406656] RBP: ffffa0896f5368f0 R08: 0000000000000246 R09: 0000000000000000 [ 111.408437] R10: ffffe19b01c01500 R11: 0000000000000000 R12: ffffa08977d28a00 [ 111.410210] R13: 0000000000000004 R14: ffffa089315303f0 R15: ffffa08931530000 [ 111.411856] FS: 0000000000000000(0000) GS:ffffa0897bc00000(0000) knlGS:0000000000000000 [ 111.413699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 111.415068] CR2: 0000000000000004 CR3: 000000002ac90004 CR4: 00000000001606f0 [ 111.416745] Call Trace: [ 111.417339] xprt_request_enqueue_transmit+0x2b6/0x4a0 [sunrpc] [ 111.418709] ? rpc_task_need_encode+0x40/0x40 [sunrpc] [ 111.419957] call_bc_transmit+0xd5/0x170 [sunrpc] [ 111.421067] __rpc_execute+0x7e/0x3f0 [sunrpc] [ 111.422177] rpc_run_bc_task+0x78/0xd0 [sunrpc] [ 111.423212] bc_svc_process+0x281/0x340 [sunrpc] [ 111.424325] nfs41_callback_svc+0x130/0x1c0 [nfsv4] [ 111.425430] ? remove_wait_queue+0x60/0x60 [ 111.426398] kthread+0xf5/0x130 [ 111.427155] ? nfs_callback_authenticate+0x50/0x50 [nfsv4] [ 111.428388] ? kthread_bind+0x10/0x10 [ 111.429270] ret_from_fork+0x1f/0x30 localhost login: [ 467.462259] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 467.464411] #PF error: [normal kernel read fault] [ 467.465445] PGD 80000000728c1067 P4D 80000000728c1067 PUD 728c0067 PMD 0 [ 467.466980] Oops: 0000 [#1] SMP PTI [ 467.467759] CPU: 0 PID: 3517 Comm: NFSv4 callback Not tainted 5.0.0-rc7+ #1 [ 467.469393] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 467.471840] RIP: 0010:trace_event_raw_event_xprt_transmit+0x7c/0xf0 [sunrpc] [ 467.473392] Code: f6 48 85 c0 74 4b 49 8b 94 24 98 00 00 00 48 89 e7 0f b7 92 e0 00 00 00 89 50 08 49 8b 94 24 98 00 00 00 48 8b 92 a8 00 00 00 <8b> 52 04 89 50 0c 41 8b 94 24 a8 00 00 00 0f ca 89 50 10 41 8b 94 [ 467.477605] RSP: 0018:ffffabe7434fbcd0 EFLAGS: 00010282 [ 467.478793] RAX: ffff99720fc3bce0 RBX: 0000000000000003 RCX: 0000000000000000 [ 467.480409] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffabe7434fbcd0 [ 467.482011] RBP: ffff99726f631948 R08: 0000000000000246 R09: 0000000000000000 [ 467.483591] R10: 0000000070000000 R11: 0000000000000000 R12: ffff997277dfcc00 [ 467.485226] R13: 0000000000000000 R14: 0000000000000000 R15: ffff99722fecdca8 [ 467.486830] FS: 0000000000000000(0000) GS:ffff99727bc00000(0000) knlGS:0000000000000000 [ 467.488596] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 467.489931] CR2: 0000000000000004 CR3: 00000000270e6006 CR4: 00000000001606f0 [ 467.491559] Call Trace: [ 467.492128] xprt_transmit+0x303/0x3f0 [sunrpc] [ 467.493143] ? rpc_task_need_encode+0x40/0x40 [sunrpc] [ 467.494328] call_bc_transmit+0x49/0x170 [sunrpc] [ 467.495379] __rpc_execute+0x7e/0x3f0 [sunrpc] [ 467.496451] rpc_run_bc_task+0x78/0xd0 [sunrpc] [ 467.497467] bc_svc_process+0x281/0x340 [sunrpc] [ 467.498507] nfs41_callback_svc+0x130/0x1c0 [nfsv4] [ 467.499751] ? remove_wait_queue+0x60/0x60 [ 467.500686] kthread+0xf5/0x130 [ 467.501438] ? nfs_callback_authenticate+0x50/0x50 [nfsv4] [ 467.502640] ? kthread_bind+0x10/0x10 [ 467.503454] ret_from_fork+0x1f/0x30 Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx> --- include/trace/events/sunrpc.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index 8451f30..7e899e6 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -712,7 +712,8 @@ TP_fast_assign( __entry->task_id = rqst->rq_task->tk_pid; - __entry->client_id = rqst->rq_task->tk_client->cl_clid; + __entry->client_id = rqst->rq_task->tk_client ? + rqst->rq_task->tk_client->cl_clid : -1; __entry->xid = be32_to_cpu(rqst->rq_xid); __entry->seqno = rqst->rq_seqno; __entry->status = status; @@ -742,7 +743,8 @@ TP_fast_assign( __entry->task_id = task->tk_pid; - __entry->client_id = task->tk_client->cl_clid; + __entry->client_id = task->tk_client ? + task->tk_client->cl_clid : -1; __entry->xid = be32_to_cpu(task->tk_rqstp->rq_xid); __entry->seqno = task->tk_rqstp->rq_seqno; __entry->stage = stage; -- 1.8.3.1
