Re: [alsa-devel] [patch] ALSA: echoaudio: use after free on error

At Wed, 5 Mar 2014 14:07:15 +0300, Dan Carpenter wrote:

There are some places where we dereference "chip" in the error message but we've already freed it.

Signed-off-by: Dan Carpenter dan.carpenter@oracle.com

Thanks, applied.

Takashi

diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c index 166ec0c120d4..9f10c9e0df5e 100644 --- a/sound/pci/echoaudio/echoaudio.c +++ b/sound/pci/echoaudio/echoaudio.c @@ -1990,8 +1990,8 @@ static int snd_echo_create(struct snd_card *card,

if ((chip->iores = request_mem_region(chip->dsp_registers_phys, sz, ECHOCARD_NAME)) == NULL) {

• snd_echo_free(chip);
  

  dev_err(chip->card->dev, "cannot get memory region\n");

• snd_echo_free(chip);
  

  return -EBUSY; } chip->dsp_registers = (volatile u32 __iomem *)

@@ -1999,8 +1999,8 @@ static int snd_echo_create(struct snd_card *card,

if (request_irq(pci->irq, snd_echo_interrupt, IRQF_SHARED, KBUILD_MODNAME, chip)) {

• snd_echo_free(chip);
  

  dev_err(chip->card->dev, "cannot grab irq\n");

• snd_echo_free(chip);
  

  return -EBUSY; } chip->irq = pci->irq;

@@ -2012,8 +2012,8 @@ static int snd_echo_create(struct snd_card *card, if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(chip->pci), sizeof(struct comm_page), &chip->commpage_dma_buf) < 0) {

• snd_echo_free(chip);
  

  dev_err(chip->card->dev, "cannot allocate the comm page\n");

• snd_echo_free(chip);
  

  return -ENOMEM; } chip->comm_page_phys = chip->commpage_dma_buf.addr;

@@ -2291,8 +2291,8 @@ static int snd_echo_resume(struct device *dev)

if (request_irq(pci->irq, snd_echo_interrupt, IRQF_SHARED, KBUILD_MODNAME, chip)) {

• snd_echo_free(chip);
  

  dev_err(chip->card->dev, "cannot grab irq\n");

• snd_echo_free(chip);
  

  return -EBUSY; } chip->irq = pci->irq;