Ensure the buffer in vfio_pci_host_match() will not overflow even when
an invalid addr parameter is provided.

Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
---
 hw/vfio/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index c89f3fbea348..94c174a773fb 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2739,7 +2739,7 @@ void vfio_pci_post_reset(VFIOPCIDevice *vdev)
 
 bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name)
 {
-    char tmp[13];
+    char tmp[36];
 
     sprintf(tmp, "%04x:%02x:%02x.%1x", addr->domain,
             addr->bus, addr->slot, addr->function);

-- 
2.53.0

On Mon, 02 Mar 2026 16:48:09 +0900
Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> wrote:

> Ensure the buffer in vfio_pci_host_match() will not overflow even when
> an invalid addr parameter is provided.

This commit log could be much more straightforward.  Something like:

    Each field of PCIHostDeviceAddress is an unsigned int, therefore
    while a valid address is limited to 13 characters, an invalid
    address could exceed the specified format, up to:

        ffffffff:ffffffff:ffffffff.ffffffff<NUL>

    This requires 36 characters with the terminator.

With that:

Reviewed-by: Alex Williamson <alex.williamson@nvidia.com>
    

> Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
> ---
>  hw/vfio/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index c89f3fbea348..94c174a773fb 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2739,7 +2739,7 @@ void vfio_pci_post_reset(VFIOPCIDevice *vdev)
>  
>  bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name)
>  {
> -    char tmp[13];
> +    char tmp[36];
>  
>      sprintf(tmp, "%04x:%02x:%02x.%1x", addr->domain,
>              addr->bus, addr->slot, addr->function);
>