[PATCH v2] powerpc/eeh: avoid possible crash when edev->pdev changes
From: Ganesh Goudar <hidden>
Date: 2024-06-13 14:06:41
Subsystem:
linux for powerpc (32-bit and 64-bit), pci enhanced error handling (eeh) for powerpc, the rest · Maintainers:
Madhavan Srinivasan, Mahesh J Salgaonkar, Linus Torvalds
If a PCI device is removed during eeh_pe_report_edev(), edev->pdev will change and can cause a crash, hold the PCI rescan/remove lock while taking a copy of edev->pdev. Signed-off-by: Ganesh Goudar <redacted> --- v2: Hold rescan lock till we get the bus address. --- arch/powerpc/kernel/eeh_pe.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index d1030bc52564..d283d281d28e 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c@@ -849,6 +849,7 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) { struct eeh_dev *edev; struct pci_dev *pdev; + struct pci_bus *bus = NULL; if (pe->type & EEH_PE_PHB) return pe->phb->bus;
@@ -859,9 +860,11 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) /* Retrieve the parent PCI bus of first (top) PCI device */ edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry); + pci_lock_rescan_remove(); pdev = eeh_dev_to_pci_dev(edev); if (pdev) - return pdev->bus; + bus = pdev->bus; + pci_unlock_rescan_remove(); - return NULL; + return bus; }
--
2.44.0