From a0af3d1104f752b6d0dba71788e3fddd67c857a7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 19 Jan 2022 18:54:52 +0100 Subject: PCI/MSI: Prevent UAF in error path When the core MSI allocation fails, then the PCI/MSI code uses an already freed MSI descriptor to unmask the MSI mask register in order to bring it back into reset state. Remove MSI_FLAG_FREE_MSI_DESCS from the PCI/MSI irqdomain flags and let the PCI/MSI code free the MSI descriptors after usage. Fixes: 0f62d941acf9 ("genirq/msi: Provide msi_domain_alloc/free_irqs_descs_locked()") Reported-by: Tong Zhang Signed-off-by: Thomas Gleixner Tested-by: Tong Zhang Acked-by: Bjorn Helgaas Link: https://lore.kernel.org/r/87r1938vbn.ffs@tglx --- drivers/pci/msi/irqdomain.c | 4 ++-- drivers/pci/msi/legacy.c | 1 - 2 files changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c index 0d63541c4052..e9cf318e6670 100644 --- a/drivers/pci/msi/irqdomain.c +++ b/drivers/pci/msi/irqdomain.c @@ -28,6 +28,7 @@ void pci_msi_teardown_msi_irqs(struct pci_dev *dev) msi_domain_free_irqs_descs_locked(domain, &dev->dev); else pci_msi_legacy_teardown_msi_irqs(dev); + msi_free_msi_descs(&dev->dev); } /** @@ -171,8 +172,7 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode, if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) pci_msi_domain_update_chip_ops(info); - info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS | - MSI_FLAG_FREE_MSI_DESCS; + info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS; if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE)) info->flags |= MSI_FLAG_MUST_REACTIVATE; diff --git a/drivers/pci/msi/legacy.c b/drivers/pci/msi/legacy.c index cdbb4689db78..db761adef652 100644 --- a/drivers/pci/msi/legacy.c +++ b/drivers/pci/msi/legacy.c @@ -77,5 +77,4 @@ void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev) { msi_device_destroy_sysfs(&dev->dev); arch_teardown_msi_irqs(dev); - msi_free_msi_descs(&dev->dev); } -- cgit v1.2.3