The patch below does not apply to the 4.4-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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3735459037114d31e5acd9894fad9aed104231a0 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
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)
