From cbb88db76a1536e02e93e5bd37ebbfbb6c4043a9 Mon Sep 17 00:00:00 2001 From: Wenwen Wang Date: Mon, 29 Apr 2019 12:45:40 -0500 Subject: [PATCH] ALSA: usx2y: fix a double free bug In usX2Y_In04_init(), a new urb is firstly created through usb_alloc_urb() and saved to 'usX2Y->In04urb'. Then, a buffer is allocated through kmalloc() and saved to 'usX2Y->In04Buf'. If the allocation of the buffer fails, the error code ENOMEM is returned after usb_free_urb(), which frees the created urb. However, the urb is actually freed at card->private_free callback, i.e., snd_usX2Y_card_private_free(). So the free operation here leads to a double free bug. To fix the above issue, simply remove usb_free_urb(). Signed-off-by: Wenwen Wang Signed-off-by: Takashi Iwai --- sound/usb/usx2y/usbusx2y.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c index 9f7bbed2c0f0..e8687b3bd3c8 100644 --- a/sound/usb/usx2y/usbusx2y.c +++ b/sound/usb/usx2y/usbusx2y.c @@ -293,10 +293,8 @@ int usX2Y_In04_init(struct usX2Ydev *usX2Y) if (! (usX2Y->In04urb = usb_alloc_urb(0, GFP_KERNEL))) return -ENOMEM; - if (! (usX2Y->In04Buf = kmalloc(21, GFP_KERNEL))) { - usb_free_urb(usX2Y->In04urb); + if (! (usX2Y->In04Buf = kmalloc(21, GFP_KERNEL))) return -ENOMEM; - } init_waitqueue_head(&usX2Y->In04WaitQueue); usb_fill_int_urb(usX2Y->In04urb, usX2Y->dev, usb_rcvintpipe(usX2Y->dev, 0x4),