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PCI/MSI: Handle msi_populate_sysfs() errors correctly

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Previously, when msi_populate_sysfs() failed, we saved the error return
value as dev->msi_irq_groups, which leads to a page fault when
free_msi_irqs() calls msi_destroy_sysfs().

To prevent this, leave dev->msi_irq_groups alone when msi_populate_sysfs()
fails.

Found by the Hulk Robot when injecting a memory allocation fault in
msi_populate_sysfs():

  BUG: unable to handle page fault for address: fffffffffffffff4
  ...
  Call Trace:
   msi_destroy_sysfs+0x30/0xa0
   free_msi_irqs+0x11d/0x1b0

Fixes: 2f170814bd ("genirq/msi: Move MSI sysfs handling from PCI to MSI core")
Link: https://lore.kernel.org/r/20211012071556.939137-1-wanghai38@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
This commit is contained in:
Wang Hai 2021-10-12 15:15:56 +08:00 committed by Bjorn Helgaas
parent e4e737bb5c
commit 2b94b6b79b
1 changed files with 12 additions and 6 deletions
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18
drivers/pci/msi.c
View File

@ -535,6 +535,7 @@ static int msi_verify_entries(struct pci_dev *dev)
static int msi_capability_init(struct pci_dev *dev, int nvec,
struct irq_affinity *affd)
{
const struct attribute_group **groups;
struct msi_desc *entry;
int ret;
@ -558,12 +559,14 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
if (ret)
goto err;
dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(dev->msi_irq_groups)) {
ret = PTR_ERR(dev->msi_irq_groups);
groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(groups)) {
ret = PTR_ERR(groups);
goto err;
}
dev->msi_irq_groups = groups;
/* Set MSI enabled bits */
pci_intx_for_msi(dev, 0);
pci_msi_set_enable(dev, 1);
@ -691,6 +694,7 @@ static void msix_mask_all(void __iomem *base, int tsize)
static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
int nvec, struct irq_affinity *affd)
{
const struct attribute_group **groups;
void __iomem *base;
int ret, tsize;
u16 control;
@ -730,12 +734,14 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
msix_update_entries(dev, entries);
dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(dev->msi_irq_groups)) {
ret = PTR_ERR(dev->msi_irq_groups);
groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(groups)) {
ret = PTR_ERR(groups);
goto out_free;
}
dev->msi_irq_groups = groups;
/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
dev->msix_enabled = 1;