From: Niels Dossche dossche.niels@gmail.com
commit a7ecbe92b9243edbe94772f6f2c854e4142a3345 upstream.
card->local_node and card->bm_retries are both always accessed under card->lock. fw_core_handle_bus_reset has a check whose condition depends on card->local_node and whose body writes to card->bm_retries. Both of these accesses are not under card->lock. Move the lock acquiring of card->lock to before this check such that these accesses do happen when card->lock is held. fw_destroy_nodes is called inside the check. Since fw_destroy_nodes already acquires card->lock inside its function body, move this out to the callsites of fw_destroy_nodes. Also add a comment to indicate which locking is necessary when calling fw_destroy_nodes.
Cc: stable@vger.kernel.org Signed-off-by: Niels Dossche dossche.niels@gmail.com Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp Link: https://lore.kernel.org/r/20220409041243.603210-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firewire/core-card.c | 3 +++ drivers/firewire/core-topology.c | 9 +++------ 2 files changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -668,6 +668,7 @@ EXPORT_SYMBOL_GPL(fw_card_release); void fw_core_remove_card(struct fw_card *card) { struct fw_card_driver dummy_driver = dummy_driver_template; + unsigned long flags;
card->driver->update_phy_reg(card, 4, PHY_LINK_ACTIVE | PHY_CONTENDER, 0); @@ -682,7 +683,9 @@ void fw_core_remove_card(struct fw_card dummy_driver.stop_iso = card->driver->stop_iso; card->driver = &dummy_driver;
+ spin_lock_irqsave(&card->lock, flags); fw_destroy_nodes(card); + spin_unlock_irqrestore(&card->lock, flags);
/* Wait for all users, especially device workqueue jobs, to finish. */ fw_card_put(card); --- a/drivers/firewire/core-topology.c +++ b/drivers/firewire/core-topology.c @@ -375,16 +375,13 @@ static void report_found_node(struct fw_ card->bm_retries = 0; }
+/* Must be called with card->lock held */ void fw_destroy_nodes(struct fw_card *card) { - unsigned long flags; - - spin_lock_irqsave(&card->lock, flags); card->color++; if (card->local_node != NULL) for_each_fw_node(card, card->local_node, report_lost_node); card->local_node = NULL; - spin_unlock_irqrestore(&card->lock, flags); }
static void move_tree(struct fw_node *node0, struct fw_node *node1, int port) @@ -510,6 +507,8 @@ void fw_core_handle_bus_reset(struct fw_ struct fw_node *local_node; unsigned long flags;
+ spin_lock_irqsave(&card->lock, flags); + /* * If the selfID buffer is not the immediate successor of the * previously processed one, we cannot reliably compare the @@ -521,8 +520,6 @@ void fw_core_handle_bus_reset(struct fw_ card->bm_retries = 0; }
- spin_lock_irqsave(&card->lock, flags); - card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated; card->node_id = node_id; /*