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

From: Greg Kroah-Hartman
Date: Tue Nov 17 2020 - 08:39:23 EST


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