diff options
| author | Takashi Iwai <tiwai@suse.de> | 2023-08-16 18:02:45 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2023-08-17 09:23:30 +0200 |
| commit | 6a66b01de48855d92450904ccfafda9d692efbb9 (patch) | |
| tree | fb71a8695685b90362ee203b8b281e53e31fae29 /sound/core | |
| parent | 7f018db19bf7cb5ba3e39ed9e51c8c5f2488dfb0 (diff) | |
ALSA: control: Don't embed ctl_dev
Embedding the ctl_dev in the snd_card object may result in UAF when
the delayed kobj release is used; at the delayed kobj release, it
still accesses the struct device itself while the card memory (that
embeds the struct device) may be already gone.
As a workaround, detach the struct device from the card object by
allocating via the new snd_device_alloc() helper. The rest are just
replacing ctl_dev access to the pointer.
This is based on the fix Curtis posted initially. In this patch, the
changes are split and use the new helper function instead.
Link: https://lore.kernel.org/r/20230801171928.1460120-1-cujomalainey@chromium.org
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Tested-by: Curtis Malainey <cujomalainey@chromium.org>
Link: https://lore.kernel.org/r/20230816160252.23396-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/control.c | 14 | ||||
| -rw-r--r-- | sound/core/control_led.c | 4 |
2 files changed, 10 insertions, 8 deletions
diff --git a/sound/core/control.c b/sound/core/control.c index e13e9d6b3b89..59c8658966d4 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -2389,7 +2389,7 @@ static int snd_ctl_dev_register(struct snd_device *device) int err; err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, - &snd_ctl_f_ops, card, &card->ctl_dev); + &snd_ctl_f_ops, card, card->ctl_dev); if (err < 0) return err; down_read(&card->controls_rwsem); @@ -2425,7 +2425,7 @@ static int snd_ctl_dev_disconnect(struct snd_device *device) up_read(&snd_ctl_layer_rwsem); up_read(&card->controls_rwsem); - return snd_unregister_device(&card->ctl_dev); + return snd_unregister_device(card->ctl_dev); } /* @@ -2447,7 +2447,7 @@ static int snd_ctl_dev_free(struct snd_device *device) xa_destroy(&card->ctl_hash); #endif up_write(&card->controls_rwsem); - put_device(&card->ctl_dev); + put_device(card->ctl_dev); return 0; } @@ -2469,12 +2469,14 @@ int snd_ctl_create(struct snd_card *card) if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS)) return -ENXIO; - snd_device_initialize(&card->ctl_dev, card); - dev_set_name(&card->ctl_dev, "controlC%d", card->number); + err = snd_device_alloc(&card->ctl_dev, card); + if (err < 0) + return err; + dev_set_name(card->ctl_dev, "controlC%d", card->number); err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops); if (err < 0) - put_device(&card->ctl_dev); + put_device(card->ctl_dev); return err; } diff --git a/sound/core/control_led.c b/sound/core/control_led.c index 67fc2a1dcf7a..a78eb48927c7 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -688,7 +688,7 @@ static void snd_ctl_led_sysfs_add(struct snd_card *card) goto cerr; led->cards[card->number] = led_card; snprintf(link_name, sizeof(link_name), "led-%s", led->name); - WARN(sysfs_create_link(&card->ctl_dev.kobj, &led_card->dev.kobj, link_name), + WARN(sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj, link_name), "can't create symlink to controlC%i device\n", card->number); WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"), "can't create symlink to card%i\n", card->number); @@ -714,7 +714,7 @@ static void snd_ctl_led_sysfs_remove(struct snd_card *card) if (!led_card) continue; snprintf(link_name, sizeof(link_name), "led-%s", led->name); - sysfs_remove_link(&card->ctl_dev.kobj, link_name); + sysfs_remove_link(&card->ctl_dev->kobj, link_name); sysfs_remove_link(&led_card->dev.kobj, "card"); device_unregister(&led_card->dev); led->cards[card->number] = NULL; |