[PATCH net 3/3] rxrpc: Fix variable overwrite

From: David Howells
Date: Wed Nov 29 2017 - 10:34:12 EST


From: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>

Values assigned to both variable resend_at and ack_at are overwritten
before they can be used.

The correct fix here is to add 'now' to the previously computed value in
resend_at and ack_at.

Addresses-Coverity-ID: 1462262
Addresses-Coverity-ID: 1462263
Addresses-Coverity-ID: 1462264
Fixes: beb8e5e4f38c ("rxrpc: Express protocol timeouts in terms of RTT")
Link: https://marc.info/?i=17004.1511808959%40warthog.procyon.org.uk
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

net/rxrpc/call_event.c | 2 +-
net/rxrpc/sendmsg.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 555274ddc514..ad2ab1103189 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -123,7 +123,7 @@ static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
else
ack_at = expiry;

- ack_at = jiffies + expiry;
+ ack_at += now;
if (time_before(ack_at, call->ack_at)) {
WRITE_ONCE(call->ack_at, ack_at);
rxrpc_reduce_call_timer(call, ack_at, now,
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index a1c53ac066a1..09f2a3e05221 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -233,7 +233,7 @@ static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
if (resend_at < 1)
resend_at = 1;

- resend_at = now + rxrpc_resend_timeout;
+ resend_at += now;
WRITE_ONCE(call->resend_at, resend_at);
rxrpc_reduce_call_timer(call, resend_at, now,
rxrpc_timer_set_for_send);