Re: [PATCH] pci: fix overflow in printf string formatting

[Paolo Bonzini <pbonzini@redhat.com>]

On 5/31/22 11:25, Claudio Fontana wrote:
> Signed-off-by: Claudio Fontana <cfontana@suse.de>
> ---
>   hw/pci/pci.c | 18 +++++++++---------
>   1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index a9b37f8000..6e7015329c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -2640,15 +2640,15 @@ static char *pci_dev_fw_name(DeviceState *dev, char *buf, int len)
>   static char *pcibus_get_fw_dev_path(DeviceState *dev)
>   {
>       PCIDevice *d = (PCIDevice *)dev;
> -    char path[50], name[33];
> -    int off;
> -
> -    off = snprintf(path, sizeof(path), "%s@%x",
> -                   pci_dev_fw_name(dev, name, sizeof name),
> -                   PCI_SLOT(d->devfn));
> -    if (PCI_FUNC(d->devfn))
> -        snprintf(path + off, sizeof(path) + off, ",%x", PCI_FUNC(d->devfn));
> -    return g_strdup(path);
> +    char name[33];
> +    int has_func = !!PCI_FUNC(d->devfn);
> +
> +    return g_strdup_printf("%s@%x%s%.*x",
> +                           pci_dev_fw_name(dev, name, sizeof(name)),
> +                           PCI_SLOT(d->devfn),
> +                           has_func ? "," : "",
> +                           has_func,
> +                           PCI_FUNC(d->devfn));
>   }
>   
>   static char *pcibus_get_dev_path(DeviceState *dev)

Cc: qemu-stable@nongnu.org