[SRU][N][PATCH 06/10] s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs

[Massimiliano Pellizzer]

From: Niklas Schnelle <schnelle at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/2114174

With commit bcb5d6c76903 ("s390/pci: introduce lock to synchronize state
of zpci_dev's") the code to ignore power off of a PF that has child VFs
was changed from a direct return to a goto to the unlock and
pci_dev_put() section. The change however left the existing pci_dev_put()
untouched resulting in a doubple put. This can subsequently cause a use
after free if the struct pci_dev is released in an unexpected state.
Fix this by removing the extra pci_dev_put().

Cc: stable at vger.kernel.org
Fixes: bcb5d6c76903 ("s390/pci: introduce lock to synchronize state of zpci_dev's")
Signed-off-by: Niklas Schnelle <schnelle at linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer at linux.ibm.com>
Signed-off-by: Heiko Carstens <hca at linux.ibm.com>
(cherry picked from commit 05a2538f2b48500cf4e8a0a0ce76623cc5bafcf1)
CVE-2025-37946
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
 drivers/pci/hotplug/s390_pci_hpc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c
index 7333b305f2a57..9be65c4103df6 100644
--- a/drivers/pci/hotplug/s390_pci_hpc.c
+++ b/drivers/pci/hotplug/s390_pci_hpc.c
@@ -59,7 +59,6 @@ static int disable_slot(struct hotplug_slot *hotplug_slot)
 
 	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
 	if (pdev && pci_num_vf(pdev)) {
-		pci_dev_put(pdev);
 		rc = -EBUSY;
 		goto out;
 	}
-- 
2.48.1