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ALSA: firewire: fix NULL pointer dereference when releasing uninitialized data of iso-resource

Message ID 20170820065426.2414-1-o-takashi@sakamocchi.jp (mailing list archive)
State Accepted
Commit 0c264af7be2013266c5b4c644f3f366399ee490a
Headers show

Commit Message

Takashi Sakamoto Aug. 20, 2017, 6:54 a.m. UTC
When calling 'iso_resource_free()' for uninitialized data, this function
causes NULL pointer dereference due to its 'unit' member. This occurs when
unplugging audio and music units on IEEE 1394 bus at failure of card
registration.

This commit fixes the bug. The bug exists since kernel v4.5.

Fixes: 324540c4e05c ('ALSA: fireface: postpone sound card registration') at v4.12
Fixes: 8865a31e0fd8 ('ALSA: firewire-motu: postpone sound card registration') at v4.12
Fixes: b610386c8afb ('ALSA: firewire-tascam: deleyed registration of sound card') at v4.7
Fixes: 86c8dd7f4da3 ('ALSA: firewire-digi00x: delayed registration of sound card') at v4.7
Fixes: 6c29230e2a5f ('ALSA: oxfw: delayed registration of sound card') at v4.7
Fixes: 7d3c1d5901aa ('ALSA: fireworks: delayed registration of sound card') at v4.7
Fixes: 04a2c73c97eb ('ALSA: bebob: delayed registration of sound card') at v4.7
Fixes: b59fb1900b4f ('ALSA: dice: postpone card registration') at v4.5
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 sound/firewire/iso-resources.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Takashi Iwai Aug. 20, 2017, 7:42 a.m. UTC | #1
On Sun, 20 Aug 2017 08:54:26 +0200,
Takashi Sakamoto wrote:
> 
> When calling 'iso_resource_free()' for uninitialized data, this function
> causes NULL pointer dereference due to its 'unit' member. This occurs when
> unplugging audio and music units on IEEE 1394 bus at failure of card
> registration.
> 
> This commit fixes the bug. The bug exists since kernel v4.5.
> 
> Fixes: 324540c4e05c ('ALSA: fireface: postpone sound card registration') at v4.12
> Fixes: 8865a31e0fd8 ('ALSA: firewire-motu: postpone sound card registration') at v4.12
> Fixes: b610386c8afb ('ALSA: firewire-tascam: deleyed registration of sound card') at v4.7
> Fixes: 86c8dd7f4da3 ('ALSA: firewire-digi00x: delayed registration of sound card') at v4.7
> Fixes: 6c29230e2a5f ('ALSA: oxfw: delayed registration of sound card') at v4.7
> Fixes: 7d3c1d5901aa ('ALSA: fireworks: delayed registration of sound card') at v4.7
> Fixes: 04a2c73c97eb ('ALSA: bebob: delayed registration of sound card') at v4.7
> Fixes: b59fb1900b4f ('ALSA: dice: postpone card registration') at v4.5
> Cc: <stable@vger.kernel.org> # v4.5+
> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Applied, thanks.


Takashi
diff mbox

Patch

diff --git a/sound/firewire/iso-resources.c b/sound/firewire/iso-resources.c
index f0e4d502d604..066b5df666f4 100644
--- a/sound/firewire/iso-resources.c
+++ b/sound/firewire/iso-resources.c
@@ -210,9 +210,14 @@  EXPORT_SYMBOL(fw_iso_resources_update);
  */
 void fw_iso_resources_free(struct fw_iso_resources *r)
 {
-	struct fw_card *card = fw_parent_device(r->unit)->card;
+	struct fw_card *card;
 	int bandwidth, channel;
 
+	/* Not initialized. */
+	if (r->unit == NULL)
+		return;
+	card = fw_parent_device(r->unit)->card;
+
 	mutex_lock(&r->mutex);
 
 	if (r->allocated) {