nvme_sriov_pre_write_ctrl() used to directly inspect SR-IOV
configurations to know the number of VFs being disabled due to SR-IOV
configuration writes, but the logic was flawed and resulted in
out-of-bound memory access.
It assumed PCI_SRIOV_NUM_VF always has the number of currently enabled
VFs, but it actually doesn't in the following cases:
- PCI_SRIOV_NUM_VF has been set but PCI_SRIOV_CTRL_VFE has never been.
- PCI_SRIOV_NUM_VF was written after PCI_SRIOV_CTRL_VFE was set.
- VFs were only partially enabled because of realization failure.
It is a responsibility of pcie_sriov to interpret SR-IOV configurations
and pcie_sriov does it correctly, so use pcie_sriov_num_vfs(), which it
provides, to get the number of enabled VFs before and after SR-IOV
configuration writes.
Cc: qemu-sta...@nongnu.org
Fixes: CVE-2024-26328
Fixes: 11871f53ef8e ("hw/nvme: Add support for the Virtualization Management
command")
Suggested-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
---
hw/nvme/ctrl.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index f026245d1e9e..7a56e7b79b4d 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -8466,36 +8466,26 @@ static void nvme_pci_reset(DeviceState *qdev)
nvme_ctrl_reset(n, NVME_RESET_FUNCTION);
}
-static void nvme_sriov_pre_write_ctrl(PCIDevice *dev, uint32_t address,
- uint32_t val, int len)
+static void nvme_sriov_post_write_config(PCIDevice *dev, uint16_t old_num_vfs)
{
NvmeCtrl *n = NVME(dev);
NvmeSecCtrlEntry *sctrl;
- uint16_t sriov_cap = dev->exp.sriov_cap;
- uint32_t off = address - sriov_cap;
- int i, num_vfs;
+ int i;
- if (!sriov_cap) {
- return;
- }
-
- if (range_covers_byte(off, len, PCI_SRIOV_CTRL)) {
- if (!(val & PCI_SRIOV_CTRL_VFE)) {
- num_vfs = pci_get_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF);
- for (i = 0; i < num_vfs; i++) {
- sctrl = &n->sec_ctrl_list.sec[i];
- nvme_virt_set_state(n, le16_to_cpu(sctrl->scid), false);
- }
- }
+ for (i = pcie_sriov_num_vfs(dev); i < old_num_vfs; i++) {
+ sctrl = &n->sec_ctrl_list.sec[i];
+ nvme_virt_set_state(n, le16_to_cpu(sctrl->scid), false);
}
}
static void nvme_pci_write_config(PCIDevice *dev, uint32_t address,
uint32_t val, int len)
{
- nvme_sriov_pre_write_ctrl(dev, address, val, len);
+ uint16_t old_num_vfs = pcie_sriov_num_vfs(dev);
+
pci_default_write_config(dev, address, val, len);
pcie_cap_flr_write_config(dev, address, val, len);
+ nvme_sriov_post_write_config(dev, old_num_vfs);
}
static const VMStateDescription nvme_vmstate = {
--
2.43.1
