The patch below does not apply to the 5.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3735459037114d31e5acd9894fad9aed104231a0 Mon Sep 17 00:00:00 2001

From: Thomas Gleixner tglx@linutronix.de Date: Tue, 9 Nov 2021 14:53:57 +0100 Subject: [PATCH] PCI/MSI: Destroy sysfs before freeing entries

free_msi_irqs() frees the MSI entries before destroying the sysfs entries which are exposing them. Nothing prevents a concurrent free while a sysfs file is read and accesses the possibly freed entry.

Move the sysfs release ahead of freeing the entries.

Fixes: 1c51b50c2995 ("PCI/MSI: Export MSI mode using attributes, not kobjects") Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Bjorn Helgaas helgaas@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87sfw5305m.ffs@tglx

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 70433013897b..48e3f4e47b29 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -368,6 +368,11 @@ static void free_msi_irqs(struct pci_dev *dev) for (i = 0; i < entry->nvec_used; i++) BUG_ON(irq_has_action(entry->irq + i));

+ if (dev->msi_irq_groups) { + msi_destroy_sysfs(&dev->dev, dev->msi_irq_groups); + dev->msi_irq_groups = NULL; + } + pci_msi_teardown_msi_irqs(dev);

list_for_each_entry_safe(entry, tmp, msi_list, list) { @@ -379,11 +384,6 @@ static void free_msi_irqs(struct pci_dev *dev) list_del(&entry->list); free_msi_entry(entry); } - - if (dev->msi_irq_groups) { - msi_destroy_sysfs(&dev->dev, dev->msi_irq_groups); - dev->msi_irq_groups = NULL; - } }

static void pci_intx_for_msi(struct pci_dev *dev, int enable)