[PATCH v2 1/2] pci: reject too large ROMs

[Paolo Bonzini]

get_image_size() returns an int64_t, which pci_add_option_rom() assigns
to an "int" without any range checking.  A 32-bit BAR could be up to
2 GiB in size, so reject anything above it.  In order to accomodate
a rounded-up size of 2 GiB, change pci_patch_ids's size argument
to unsigned.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/pci/pci.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index a6b0c5602e..bbce10050b 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -25,6 +25,7 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qemu/datadir.h"
+#include "qemu/units.h"
 #include "hw/irq.h"
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bridge.h"
@@ -2258,7 +2258,7 @@ static uint8_t pci_find_capability_at_offset(PCIDevice 
*pdev, uint8_t offset)
 
 /* Patch the PCI vendor and device ids in a PCI rom image if necessary.
    This is needed for an option rom which is used for more than one device. */
-static void pci_patch_ids(PCIDevice *pdev, uint8_t *ptr, int size)
+static void pci_patch_ids(PCIDevice *pdev, uint8_t *ptr, uint32_t size)
 {
     uint16_t vendor_id;
     uint16_t device_id;
@@ -2316,7 +2316,7 @@ static void pci_patch_ids(PCIDevice *pdev, uint8_t *ptr, 
int size)
 static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom,
                                Error **errp)
 {
-    int size;
+    int64_t size;
     char *path;
     void *ptr;
     char name[32];
@@ -2366,6 +2366,11 @@ static void pci_add_option_rom(PCIDevice *pdev, bool 
is_default_rom,
         error_setg(errp, "romfile \"%s\" is empty", pdev->romfile);
         g_free(path);
         return;
+    } else if (size > 2 * GiB) {
+        error_setg(errp, "romfile \"%s\" too large (size cannot exceed 2 GiB)",
+                   pdev->romfile);
+        g_free(path);
+        return;
     }
     size = pow2ceil(size);
 
-- 
2.29.2