firewire: fix panic in handle_at_packet
This fixes a use-after-free bug in the handling of split transactions.
The AT DMA handler of the request was occasionally executed after the
AR DMA handler of the response. The AT DMA handler then accessed an
already freed packet.
Reported by Johannes Berg.
http://bugzilla.kernel.org/show_bug.cgi?id=9617
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 99529e5..e6f1bda 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -736,6 +736,12 @@
break;
}
+ /*
+ * The response handler may be executed while the request handler
+ * is still pending. Cancel the request handler.
+ */
+ card->driver->cancel_packet(card, &t->packet);
+
t->callback(card, rcode, data, data_length, t->callback_data);
}
EXPORT_SYMBOL(fw_core_handle_response);