When rdma server returns a fault reply, rpcrdma may treats it as a bcall.
As using NFSv3, a bc server is never exist.
rpcrdma_bc_receive_call will meets NULL pointer as,
[ 226.057890] BUG: unable to handle kernel NULL pointer dereference at
00000000000000c8
...
[ 226.058704] RIP: 0010:_raw_spin_lock+0xc/0x20
...
[ 226.059732] Call Trace:
[ 226.059878] rpcrdma_bc_receive_call+0x138/0x327 [rpcrdma]
[ 226.060011] __ib_process_cq+0x89/0x170 [ib_core]
[ 226.060092] ib_cq_poll_work+0x26/0x80 [ib_core]
[ 226.060257] process_one_work+0x1a7/0x360
[ 226.060367] ? create_worker+0x1a0/0x1a0
[ 226.060440] worker_thread+0x30/0x390
[ 226.060500] ? create_worker+0x1a0/0x1a0
[ 226.060574] kthread+0x116/0x130
[ 226.060661] ? kthread_flush_work_fn+0x10/0x10
[ 226.060724] ret_from_fork+0x35/0x40
...
Signed-off-by: Kinglong Mee <kinglongmee@xxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 281ddb87ac8d..9486bb98eb2f 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1121,9 +1121,14 @@ static bool
rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep)
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
{
+ struct rpc_xprt *xprt = &r_xprt->rx_xprt;
struct xdr_stream *xdr = &rep->rr_stream;
__be32 *p;
+ /* no bc service, not a bcall. */
+ if (xprt->bc_serv == NULL)
+ return false;
+
if (rep->rr_proc != rdma_msg)
return false;
--
2.27.0
