From 12ed719291a953d443921f9cdb0ffee41066c340 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Sat, 21 Feb 2015 23:54:57 +0900 Subject: [PATCH] ALSA: fireworks/bebob/dice/oxfw: add reference-counting for FireWire unit Fireworks and Dice drivers try to touch instances of FireWire unit after sound card object is released, while references to the unit is decremented in .remove(). When unplugging during streaming, sound card object is released after .remove(), thus Fireworks and Dice drivers causes GPF or Null-pointer-dereferencing to application processes because an instance of FireWire unit was already released. This commit adds reference-counting for FireWire unit in drivers to allow them to touch an instance of FireWire unit after .remove(). In most case, any operations after .remove() may be failed safely. Signed-off-by: Takashi Sakamoto Cc: # 3.19+ Signed-off-by: Takashi Iwai --- sound/firewire/bebob/bebob.c | 12 +++++++++++- sound/firewire/dice/dice.c | 11 ++++++++++- sound/firewire/fireworks/fireworks.c | 12 +++++++++++- sound/firewire/oxfw/oxfw.c | 11 ++++++++++- 4 files changed, 42 insertions(+), 4 deletions(-) diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c index fc19c99654aa..b612599fb543 100644 --- a/sound/firewire/bebob/bebob.c +++ b/sound/firewire/bebob/bebob.c @@ -116,11 +116,19 @@ name_device(struct snd_bebob *bebob, unsigned int vendor_id) return err; } +/* + * This module releases the FireWire unit data after all ALSA character devices + * are released by applications. This is for releasing stream data or finishing + * transactions safely. Thus at returning from .remove(), this module still keep + * references for the unit. + */ static void bebob_card_free(struct snd_card *card) { struct snd_bebob *bebob = card->private_data; + fw_unit_put(bebob->unit); + if (bebob->card_index >= 0) { mutex_lock(&devices_mutex); clear_bit(bebob->card_index, devices_used); @@ -205,7 +213,7 @@ bebob_probe(struct fw_unit *unit, card->private_free = bebob_card_free; bebob->card = card; - bebob->unit = unit; + bebob->unit = fw_unit_get(unit); bebob->spec = spec; mutex_init(&bebob->mutex); spin_lock_init(&bebob->lock); @@ -310,6 +318,8 @@ static void bebob_remove(struct fw_unit *unit) snd_bebob_stream_destroy_duplex(bebob); snd_card_disconnect(bebob->card); + + /* No need to wait for releasing card object in this context. */ snd_card_free_when_closed(bebob->card); } diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c index 90d8f40ff727..797f0726fc74 100644 --- a/sound/firewire/dice/dice.c +++ b/sound/firewire/dice/dice.c @@ -226,11 +226,19 @@ static void dice_card_strings(struct snd_dice *dice) strcpy(card->mixername, "DICE"); } +/* + * This module releases the FireWire unit data after all ALSA character devices + * are released by applications. This is for releasing stream data or finishing + * transactions safely. Thus at returning from .remove(), this module still keep + * references for the unit. + */ static void dice_card_free(struct snd_card *card) { struct snd_dice *dice = card->private_data; snd_dice_transaction_destroy(dice); + fw_unit_put(dice->unit); + mutex_destroy(&dice->mutex); } @@ -251,7 +259,7 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id) dice = card->private_data; dice->card = card; - dice->unit = unit; + dice->unit = fw_unit_get(unit); card->private_free = dice_card_free; spin_lock_init(&dice->lock); @@ -309,6 +317,7 @@ static void dice_remove(struct fw_unit *unit) snd_dice_stream_destroy_duplex(dice); + /* No need to wait for releasing card object in this context. */ snd_card_free_when_closed(dice->card); } diff --git a/sound/firewire/fireworks/fireworks.c b/sound/firewire/fireworks/fireworks.c index 3e2ed8e82cbc..1e33394d8a93 100644 --- a/sound/firewire/fireworks/fireworks.c +++ b/sound/firewire/fireworks/fireworks.c @@ -173,11 +173,19 @@ get_hardware_info(struct snd_efw *efw) return err; } +/* + * This module releases the FireWire unit data after all ALSA character devices + * are released by applications. This is for releasing stream data or finishing + * transactions safely. Thus at returning from .remove(), this module still keep + * references for the unit. + */ static void efw_card_free(struct snd_card *card) { struct snd_efw *efw = card->private_data; + fw_unit_put(efw->unit); + if (efw->card_index >= 0) { mutex_lock(&devices_mutex); clear_bit(efw->card_index, devices_used); @@ -218,7 +226,7 @@ efw_probe(struct fw_unit *unit, card->private_free = efw_card_free; efw->card = card; - efw->unit = unit; + efw->unit = fw_unit_get(unit); mutex_init(&efw->mutex); spin_lock_init(&efw->lock); init_waitqueue_head(&efw->hwdep_wait); @@ -293,6 +301,8 @@ static void efw_remove(struct fw_unit *unit) snd_efw_transaction_remove_instance(efw); snd_card_disconnect(efw->card); + + /* No need to wait for releasing card object in this context. */ snd_card_free_when_closed(efw->card); } diff --git a/sound/firewire/oxfw/oxfw.c b/sound/firewire/oxfw/oxfw.c index 60e5cad0531a..1607b26404c3 100644 --- a/sound/firewire/oxfw/oxfw.c +++ b/sound/firewire/oxfw/oxfw.c @@ -104,11 +104,19 @@ static int name_card(struct snd_oxfw *oxfw) return err; } +/* + * This module releases the FireWire unit data after all ALSA character devices + * are released by applications. This is for releasing stream data or finishing + * transactions safely. Thus at returning from .remove(), this module still keep + * references for the unit. + */ static void oxfw_card_free(struct snd_card *card) { struct snd_oxfw *oxfw = card->private_data; unsigned int i; + fw_unit_put(oxfw->unit); + for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) { kfree(oxfw->tx_stream_formats[i]); kfree(oxfw->rx_stream_formats[i]); @@ -136,7 +144,7 @@ static int oxfw_probe(struct fw_unit *unit, oxfw = card->private_data; oxfw->card = card; mutex_init(&oxfw->mutex); - oxfw->unit = unit; + oxfw->unit = fw_unit_get(unit); oxfw->device_info = (const struct device_info *)id->driver_data; spin_lock_init(&oxfw->lock); init_waitqueue_head(&oxfw->hwdep_wait); @@ -218,6 +226,7 @@ static void oxfw_remove(struct fw_unit *unit) if (oxfw->has_output) snd_oxfw_stream_destroy_simplex(oxfw, &oxfw->tx_stream); + /* No need to wait for releasing card object in this context. */ snd_card_free_when_closed(oxfw->card); }