From 26b73bae01d6eb81a4a38f36101812f20b2639de Mon Sep 17 00:00:00 2001 From: Ali Tariq Date: Thu, 23 Jul 2026 19:04:33 +0500 Subject: [PATCH] PCI: plda: Fix use-after-free of event IRQs during teardown plda_pcie_irq_domain_deinit() removes pcie->event_domain via irq_domain_remove(), but the per-event IRQs mapped from that domain are requested with devm_request_irq() in plda_init_interrupts(). The actual free_irq() for a devm-managed IRQ is deferred by devres until after the calling probe()/remove() function returns. This means irq_domain_remove() can free the domain's internal data before the deferred free_irq() for IRQs still mapped into it has run. When devres later processes that deferred cleanup, it can end up dereferencing the already-freed domain. Free each event IRQ explicitly with devm_free_irq() before removing the domain. This triggers the free immediately and removes the IRQ from the devres tracking list, so devres will not attempt to free it a second time later. Also dispose of the event, INTx, and MSI IRQ mappings with irq_dispose_mapping() before their owning domains are removed. Finally, guard the calls to irq_set_chained_handler_and_data() for pcie->irq, pcie->msi_irq, and pcie->intx_irq so they only run when those fields hold a valid (>0) IRQ number. This is a pre-existing issue, flagged by automated review during work on an earlier, unrelated patch to this driver. Build-tested and boot-tested on StarFive VisionFive v1.2A board Fixes: 76c911396807 ("PCI: plda: Add host init/deinit and map bus functions") Closes: https://lore.kernel.org/linux-pci/20260714115343.4D49E1F000E9@smtp.kernel.org/ Signed-off-by: Ali Tariq Signed-off-by: Manivannan Sadhasivam Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260723140434.675512-2-alitariq45892@gmail.com --- drivers/pci/controller/plda/pcie-plda-host.c | 24 +++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/plda/pcie-plda-host.c b/drivers/pci/controller/plda/pcie-plda-host.c index f9a34f323ad8..791f5c1cce06 100644 --- a/drivers/pci/controller/plda/pcie-plda-host.c +++ b/drivers/pci/controller/plda/pcie-plda-host.c @@ -559,9 +559,27 @@ EXPORT_SYMBOL_GPL(plda_pcie_setup_iomems); static void plda_pcie_irq_domain_deinit(struct plda_pcie_rp *pcie) { - irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); - irq_set_chained_handler_and_data(pcie->msi_irq, NULL, NULL); - irq_set_chained_handler_and_data(pcie->intx_irq, NULL, NULL); + u32 i, event_irq; + + if (pcie->irq > 0) + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); + if (pcie->msi_irq > 0) + irq_set_chained_handler_and_data(pcie->msi_irq, NULL, NULL); + if (pcie->intx_irq > 0) + irq_set_chained_handler_and_data(pcie->intx_irq, NULL, NULL); + + for_each_set_bit(i, &pcie->events_bitmap, pcie->num_events) { + event_irq = irq_find_mapping(pcie->event_domain, i); + if (event_irq) { + devm_free_irq(pcie->dev, event_irq, pcie); + irq_dispose_mapping(event_irq); + } + } + + if (pcie->intx_irq) + irq_dispose_mapping(pcie->intx_irq); + if (pcie->msi_irq) + irq_dispose_mapping(pcie->msi_irq); irq_domain_remove(pcie->msi.dev_domain);