From f7dcc5e33c1e4b0d278a30f7d2f0c9a63d7b40ca Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Wed, 10 May 2023 10:35:33 +0900 Subject: [PATCH] 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 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 --- drivers/firewire/net.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index af22be84034b..538bd677c254 100644 --- 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); }