[PATCH net 2/2] rxrpc: Fix uninitialised variable in rxrpc_send_data()

David Howells
2024-10-01T13:27:21Z

Fix the uninitialised txb variable in rxrpc_send_data() by moving the code
that loads it above all the jumps to maybe_error, txb being stored back
into call->tx_pending right before the normal return.

Fixes: b0f571ecd794 ("rxrpc: Fix locking in rxrpc's sendmsg")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lists.infradead.org/pipermail/linux-afs/2024-October/008896.html
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
---
net/rxrpc/sendmsg.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 894b8fa68e5e..23d18fe5de9f 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -303,6 +303,11 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);

reload:
+ txb = call->tx_pending;
+ call->tx_pending = NULL;
+ if (txb)
+ rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
+
ret = -EPIPE;
if (sk->sk_shutdown & SEND_SHUTDOWN)
goto maybe_error;
@@ -329,11 +334,6 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
goto maybe_error;
}

- txb = call->tx_pending;
- call->tx_pending = NULL;
- if (txb)
- rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
-
do {
if (!txb) {
size_t remain;