5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ganesh Goudar ganeshgr@linux.ibm.com
[ Upstream commit a1216e62d039bf63a539bbe718536ec789a853dd ]
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->bus.
Signed-off-by: Ganesh Goudar ganeshgr@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240617140240.580453-1-ganeshgr@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 177852e39a253..4b6b1846e4d23 100644 --- a/arch/powerpc/kernel/eeh_pe.c +++ b/arch/powerpc/kernel/eeh_pe.c @@ -922,6 +922,7 @@ 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; @@ -932,9 +933,11 @@ 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; }