rxrpc: fix uninitialized pointer dereference in debug code

A newly added bugfix caused an uninitialized variable to be
used for printing debug output. This is harmless as long
as the debug setting is disabled, but otherwise leads to an
immediate crash.

gcc warns about this when -Wmaybe-uninitialized is enabled:

net/rxrpc/call_object.c: In function 'rxrpc_release_call':
net/rxrpc/call_object.c:496:163: error: 'sp' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The initialization was removed but one of the users remains.
This adds back the initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 372ee16386bb ("rxrpc: Fix races between skb free, ACK generation and replying")
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index c47f14fc5e888b52badd3f9306ad8d712cb81f66..e8c953c48cb8f596a9dae299443f31f1e316ad0f 100644 (file)
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -493,6 +493,7 @@ void rxrpc_release_call(struct rxrpc_call *call)
                       (skb = skb_dequeue(&call->rx_oos_queue))) {
                        spin_unlock_bh(&call->lock);
 
+                       sp = rxrpc_skb(skb);
                        _debug("- zap %s %%%u #%u",
                               rxrpc_pkts[sp->hdr.type],
                               sp->hdr.serial, sp->hdr.seq);