| Message ID | 20210323023501.11314-1-lyl2019@mail.ustc.edu.cn (mailing list archive) |
|---|---|
| State | Deferred |
| Headers | show |
| Series | scsi: fix a error refcount get in pcie_device_make_active | expand |
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c index ffca03064797..17061f54d616 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -11432,12 +11432,12 @@ static void pcie_device_make_active(struct MPT3SAS_ADAPTER *ioc, unsigned long flags; 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);
In pcie_device_make_active, pcie_device may be freed by pcie_device_put(pcie_device). After it, the refcount of pcie_device is increased by pcie_device_get(pcie_device). The pcie_device is freed but refcount is non-zero. It could cause use after free later. My patch puts the pcie_device_get() ahead of pcie_device_put() to avoid uaf. Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> --- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)