[libvirt] [PATCH] pci: fix null pointer dereference

[Daniel P. Berrange]

On Tue, May 03, 2011 at 09:34:11AM -0600, Eric Blake wrote:
> Clang detected a null-pointer dereference regression, introduced
> in commit 4e8969eb.  Without this patch, a device with
> unbind_from_stub set to false would eventually try to call
> virFileExists on uncomputed drvdir.
> 
> * src/util/pci.c (pciUnbindDeviceFromStub): Ensure drvdir is set
> before use.
> ---
>  src/util/pci.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/src/util/pci.c b/src/util/pci.c
> index 945f32a..d7f74f9 100644
> --- a/src/util/pci.c
> +++ b/src/util/pci.c
> @@ -879,15 +879,16 @@ pciUnbindDeviceFromStub(pciDevice *dev, const char *driver)
>      char *drvdir = NULL;
>      char *path = NULL;
> 
> +    if (pciDriverDir(&drvdir, driver) < 0)
> +        goto cleanup;
> +
>      if (!dev->unbind_from_stub)
>          goto remove_slot;
> 
>      /* If the device is bound to stub, unbind it.
>       */
> -    if (pciDriverDir(&drvdir, driver) < 0 ||
> -        pciDeviceFile(&path, dev->name, "driver") < 0) {
> +    if (pciDeviceFile(&path, dev->name, "driver") < 0)
>          goto cleanup;
> -    }
> 
>      if (virFileExists(drvdir) && virFileLinkPointsTo(path, drvdir)) {
>          if (pciDriverFile(&path, driver, "unbind") < 0) {

ACK


Daniel
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