[PATCH] scsi: Fix a use after free in pcie_device_make_active

From: Lv Yunlong
Date: Thu Mar 11 2021 - 01:21:01 EST


In pcie_device_make_active, it will drop the last reference
of pcie_device and release it by pcie_device_put(). It is
obviously that pcie_device_get() should be called before
release the pcie_device. Otherwise, it will cause a use after
free.

Fixes: d88e1eaba6eee ("scsi: mpt3sas: Add nvme device support in slave alloc, target alloc a…")
Signed-off-by: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index ffca03064797..d39b5a1f496b 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -11433,11 +11433,11 @@ static void pcie_device_make_active(struct MPT3SAS_ADAPTER *ioc,

spin_lock_irqsave(&ioc->pcie_device_lock, flags);

+ pcie_device_get(pcie_device);
if (!list_empty(&pcie_device->list)) {
list_del_init(&pcie_device->list);
pcie_device_put(pcie_device);
}
- pcie_device_get(pcie_device);
list_add_tail(&pcie_device->list, &ioc->pcie_device_list);

spin_unlock_irqrestore(&ioc->pcie_device_lock, flags);
--
2.25.1