[alsa-devel] [PATCH v3] ALSA: ymfpci: Handle return NULL error from ioremap_nocache
Here, If ioremap_nocache will fail. It will return NULL. Kernel can run into a NULL-pointer dereference. This error check will avoid NULL pointer dereference.
Signed-off-by: Arvind Yadav arvind.yadav.cs@gmail.com --- sound/pci/ymfpci/ymfpci_main.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/sound/pci/ymfpci/ymfpci_main.c b/sound/pci/ymfpci/ymfpci_main.c index ffee284..8be1f07 100644 --- a/sound/pci/ymfpci/ymfpci_main.c +++ b/sound/pci/ymfpci/ymfpci_main.c @@ -2392,6 +2392,10 @@ int snd_ymfpci_create(struct snd_card *card, chip->rev = pci->revision; chip->reg_area_phys = pci_resource_start(pci, 0); chip->reg_area_virt = ioremap_nocache(chip->reg_area_phys, 0x8000); + if (!chip->reg_area_virt) { + snd_ymfpci_free(chip); + return -ENOMEM; + } pci_set_master(pci); chip->src441_used = -1;
On Tue, 24 Jan 2017 06:31:26 +0100, Arvind Yadav wrote:
Here, If ioremap_nocache will fail. It will return NULL. Kernel can run into a NULL-pointer dereference. This error check will avoid NULL pointer dereference.
Signed-off-by: Arvind Yadav arvind.yadav.cs@gmail.com
sound/pci/ymfpci/ymfpci_main.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/sound/pci/ymfpci/ymfpci_main.c b/sound/pci/ymfpci/ymfpci_main.c index ffee284..8be1f07 100644 --- a/sound/pci/ymfpci/ymfpci_main.c +++ b/sound/pci/ymfpci/ymfpci_main.c @@ -2392,6 +2392,10 @@ int snd_ymfpci_create(struct snd_card *card, chip->rev = pci->revision; chip->reg_area_phys = pci_resource_start(pci, 0); chip->reg_area_virt = ioremap_nocache(chip->reg_area_phys, 0x8000);
- if (!chip->reg_area_virt) {
snd_ymfpci_free(chip);
The function calls iounmap() unconditionally, so it's not appropriate to call as is. You need to fix snd_ymfpci_free() as well to check NULL before iounmap(). Or, call here kfree() and pci_disable_device() explicitly instead of a full destructor.
thanks,
Takashi
participants (2)
-
Arvind Yadav -
Takashi Iwai