This is a note to let you know that I've just added the patch titled
pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv
to the 5.4-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-hotplug-pnv_php-fix-hotplug-driver-crash-on-powe.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 579e1d2e8d3455d92528317dca64df0facbfb32c
Author: Krishna Kumar <krishnak@xxxxxxxxxxxxx>
Date: Mon Jul 1 13:15:06 2024 +0530
pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv
[ Upstream commit 335e35b748527f0c06ded9eebb65387f60647fda ]
The hotplug driver for powerpc (pci/hotplug/pnv_php.c) causes a kernel
crash when we try to hot-unplug/disable the PCIe switch/bridge from
the PHB.
The crash occurs because although the MSI data structure has been
released during disable/hot-unplug path and it has been assigned
with NULL, still during unregistration the code was again trying to
explicitly disable the MSI which causes the NULL pointer dereference and
kernel crash.
The patch fixes the check during unregistration path to prevent invoking
pci_disable_msi/msix() since its data structure is already freed.
Reported-by: Timothy Pearson <tpearson@xxxxxxxxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/1981605666.2142272.1703742465927.JavaMail.zimbra@xxxxxxxxxxxxxxxxxxxxxxxx/
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Tested-by: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Krishna Kumar <krishnak@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20240701074513.94873-2-krishnak@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index d7b2b47bc33e..382494261830 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -35,7 +35,6 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot,
bool disable_device)
{
struct pci_dev *pdev = php_slot->pdev;
- int irq = php_slot->irq;
u16 ctrl;
if (php_slot->irq > 0) {
@@ -54,7 +53,7 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot,
php_slot->wq = NULL;
}
- if (disable_device || irq > 0) {
+ if (disable_device) {
if (pdev->msix_enabled)
pci_disable_msix(pdev);
else if (pdev->msi_enabled)
