This is a note to let you know that I've just added the patch titled
PCI/MSI: Destroy sysfs before freeing entries
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-msi-destroy-sysfs-before-freeing-entries.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3735459037114d31e5acd9894fad9aed104231a0 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Tue, 9 Nov 2021 14:53:57 +0100
Subject: PCI/MSI: Destroy sysfs before freeing entries
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
commit 3735459037114d31e5acd9894fad9aed104231a0 upstream.
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
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/msi.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -391,18 +391,6 @@ static void free_msi_irqs(struct pci_dev
for (i = 0; i < entry->nvec_used; i++)
BUG_ON(irq_has_action(entry->irq + i));
- pci_msi_teardown_msi_irqs(dev);
-
- list_for_each_entry_safe(entry, tmp, msi_list, list) {
- if (entry->msi_attrib.is_msix) {
- if (list_is_last(&entry->list, msi_list))
- iounmap(entry->mask_base);
- }
-
- list_del(&entry->list);
- kfree(entry);
- }
-
if (dev->msi_irq_groups) {
sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);
msi_attrs = dev->msi_irq_groups[0]->attrs;
@@ -418,6 +406,18 @@ static void free_msi_irqs(struct pci_dev
kfree(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) {
+ if (entry->msi_attrib.is_msix) {
+ if (list_is_last(&entry->list, msi_list))
+ iounmap(entry->mask_base);
+ }
+
+ list_del(&entry->list);
+ free_msi_entry(entry);
+ }
}
static void pci_intx_for_msi(struct pci_dev *dev, int enable)
Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are
queue-4.9/pci-msi-destroy-sysfs-before-freeing-entries.patch
queue-4.9/irq-mips-avoid-nested-irq_enter.patch
