[PATCH 5.9 143/255] SUNRPC: Fix general protection fault in trace_rpc_xdr_overflow()

[Greg Kroah-Hartman]

From: Chuck Lever <chuck.lever@xxxxxxxxxx>

[ Upstream commit d321ff589c16d8c2207485a6d7fbdb14e873d46e ]

The TP_fast_assign() section is careful enough not to dereference
xdr->rqst if it's NULL. The TP_STRUCT__entry section is not.

Fixes: 5582863f450c ("SUNRPC: Add XDR overflow trace event")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 include/trace/events/sunrpc.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 65d7dfbbc9cd7..ca2f27b9f919d 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -607,10 +607,10 @@ TRACE_EVENT(rpc_xdr_overflow,
 		__field(size_t, tail_len)
 		__field(unsigned int, page_len)
 		__field(unsigned int, len)
-		__string(progname,
-			 xdr->rqst->rq_task->tk_client->cl_program->name)
-		__string(procedure,
-			 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name)
+		__string(progname, xdr->rqst ?
+			 xdr->rqst->rq_task->tk_client->cl_program->name : "unknown")
+		__string(procedure, xdr->rqst ?
+			 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name : "unknown")
 	),
 
 	TP_fast_assign(
-- 
2.27.0