firewire: net: fix unexpected release of object for asynchronous request packet

The lifetime of object for asynchronous request packet is now maintained
by reference counting, while current implementation of firewire-net
releases the passed object in the handler.

This commit fixes the bug.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y%2Fymx6WZIAlrtjLc@workstation/
Fixes: 13a55d6bb15f ("firewire: core: use kref structure to maintain lifetime of data for fw_request structure")
Link: https://lore.kernel.org/lkml/20230510031205.782032-1-o-takashi@sakamocchi.jp/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index af22be84034bba2cc310de835d045b788d40b00f..538bd677c254a9a148b5d2772d56f16559db4f07 100644 (file)
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -706,21 +706,22 @@ static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
        int rcode;
 
        if (destination == IEEE1394_ALL_NODES) {
-               kfree(r);
-
-               return;
-       }
-
-       if (offset != dev->handler.offset)
+               // Although the response to the broadcast packet is not necessarily required, the
+               // fw_send_response() function should still be called to maintain the reference
+               // counting of the object. In the case, the call of function just releases the
+               // object as a result to decrease the reference counting.
+               rcode = RCODE_COMPLETE;
+       } else if (offset != dev->handler.offset) {
                rcode = RCODE_ADDRESS_ERROR;
-       else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
+       } else if (tcode != TCODE_WRITE_BLOCK_REQUEST) {
                rcode = RCODE_TYPE_ERROR;
-       else if (fwnet_incoming_packet(dev, payload, length,
-                                      source, generation, false) != 0) {
+       } else if (fwnet_incoming_packet(dev, payload, length,
+                                        source, generation, false) != 0) {
                dev_err(&dev->netdev->dev, "incoming packet failure\n");
                rcode = RCODE_CONFLICT_ERROR;
-       } else
+       } else {
                rcode = RCODE_COMPLETE;
+       }
 
        fw_send_response(card, r, rcode);
 }