[PATCH v4 5/9] pcie_sriov: Validate NumVFs

From: Akihiko Odaki <akihiko.odaki@daynix.com>
To: "Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Cédric Le Goater" <clg@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <eduardo@habkost.net>,
	"Sriram Yagnaraman" <sriram.yagnaraman@est.tech>,
	"Jason Wang" <jasowang@redhat.com>,
	"Keith Busch" <kbusch@kernel.org>,
	"Klaus Jensen" <its@irrelevant.dk>
Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org,
	 Akihiko Odaki <akihiko.odaki@daynix.com>
Subject: [PATCH v4 5/9] pcie_sriov: Validate NumVFs
Date: Wed, 14 Feb 2024 14:13:43 +0900	[thread overview]
Message-ID: <20240214-reuse-v4-5-89ad093a07f4@daynix.com> (raw)
In-Reply-To: <20240214-reuse-v4-0-89ad093a07f4@daynix.com>

The guest may write NumVFs greater than TotalVFs and that can lead
to buffer overflow in VF implementations.

Fixes: 7c0fa8dff811 ("pcie: Add support for Single Root I/O Virtualization (SR/IOV)")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 hw/pci/pcie_sriov.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c
index a1fe65f5d801..da209b7f47fd 100644
--- a/hw/pci/pcie_sriov.c
+++ b/hw/pci/pcie_sriov.c
@@ -176,6 +176,9 @@ static void register_vfs(PCIDevice *dev)
 
     assert(sriov_cap > 0);
     num_vfs = pci_get_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF);
+    if (num_vfs > pci_get_word(dev->config + sriov_cap + PCI_SRIOV_TOTAL_VF)) {
+        return;
+    }
 
     dev->exp.sriov_pf.vf = g_new(PCIDevice *, num_vfs);
 

-- 
2.43.0


