From: Krishna Kumar krishnak@linux.ibm.com
stable inclusion from stable-v5.10.226 commit bc1faed19db95abf0933b104910a3fb01b138f59 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IARWMF CVE: CVE-2024-46761
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 335e35b748527f0c06ded9eebb65387f60647fda ]
The hotplug driver for powerpc (pci/hotplug/pnv_php.c) causes a kernel crash when we try to hot-unplug/disable the PCIe switch/bridge from the PHB.
The crash occurs because although the MSI data structure has been released during disable/hot-unplug path and it has been assigned with NULL, still during unregistration the code was again trying to explicitly disable the MSI which causes the NULL pointer dereference and kernel crash.
The patch fixes the check during unregistration path to prevent invoking pci_disable_msi/msix() since its data structure is already freed.
Reported-by: Timothy Pearson tpearson@raptorengineering.com Closes: https://lore.kernel.org/all/1981605666.2142272.1703742465927.JavaMail.zimbra... Acked-by: Bjorn Helgaas bhelgaas@google.com Tested-by: Shawn Anastasio sanastasio@raptorengineering.com Signed-off-by: Krishna Kumar krishnak@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240701074513.94873-2-krishnak@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zeng Heng zengheng4@huawei.com --- drivers/pci/hotplug/pnv_php.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 04565162a449..cf9c0e75f0be 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -38,7 +38,6 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot, bool disable_device) { struct pci_dev *pdev = php_slot->pdev; - int irq = php_slot->irq; u16 ctrl;
if (php_slot->irq > 0) { @@ -57,7 +56,7 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot, php_slot->wq = NULL; }
- if (disable_device || irq > 0) { + if (disable_device) { if (pdev->msix_enabled) pci_disable_msix(pdev); else if (pdev->msi_enabled)