[tip: irq/urgent] PCI/MSI: Prevent UAF in error path
From: tip-bot2 for Thomas Gleixner
Date: Thu Jan 20 2022 - 20:20:01 EST
The following commit has been merged into the irq/urgent branch of tip:
Commit-ID: a0af3d1104f752b6d0dba71788e3fddd67c857a7
Gitweb: https://git.kernel.org/tip/a0af3d1104f752b6d0dba71788e3fddd67c857a7
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 19 Jan 2022 18:54:52 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 21 Jan 2022 02:14:46 +01:00
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 <ztong0001@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Tong Zhang <ztong0001@xxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
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(-)
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index 0d63541..e9cf318 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 cdbb468..db761ad 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);
}