From: yuuzheng <yuuzheng@xxxxxxxxxx> [ Upstream commit 1f889b58716a5f5e3e4fe0e6742c1a4472f29ac1 ] A use-after-free or null-pointer error occurs when the 251-byte response data is copied from IOMB buffer to response message buffer in function pm8001_mpi_get_nvmd_resp(). After sending the command get_nvmd_data(), the caller begins to sleep by calling wait_for_complete() and waits for the wake-up from calling complete() in pm8001_mpi_get_nvmd_resp(). Due to unexpected events (e.g., interrupt), if response buffer gets freed before memcpy(), a use-after-free error will occur. To fix this, the complete() should be called after memcpy(). Link: https://lore.kernel.org/r/20201102165528.26510-5-Viswas.G@xxxxxxxxxxxxxxxxx Acked-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx> Signed-off-by: yuuzheng <yuuzheng@xxxxxxxxxx> Signed-off-by: Viswas G <Viswas.G@xxxxxxxxxxxxx> Signed-off-by: Ruksar Devadi <Ruksar.devadi@xxxxxxxxxxxxx> Signed-off-by: Radha Ramachandran <radha@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/pm8001/pm8001_hwi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/pm8001/pm8001_hwi.c b/drivers/scsi/pm8001/pm8001_hwi.c index 3e814c0469fbd..026bf39e3892d 100644 --- a/drivers/scsi/pm8001/pm8001_hwi.c +++ b/drivers/scsi/pm8001/pm8001_hwi.c @@ -3196,10 +3196,15 @@ pm8001_mpi_get_nvmd_resp(struct pm8001_hba_info *pm8001_ha, void *piomb) pm8001_ha->memoryMap.region[NVMD].virt_ptr, fw_control_context->len); kfree(ccb->fw_control_context); + /* To avoid race condition, complete should be + * called after the message is copied to + * fw_control_context->usrAddr + */ + complete(pm8001_ha->nvmd_completion); + PM8001_MSG_DBG(pm8001_ha, pm8001_printk("Set nvm data complete!\n")); ccb->task = NULL; ccb->ccb_tag = 0xFFFFFFFF; pm8001_tag_free(pm8001_ha, tag); - complete(pm8001_ha->nvmd_completion); } int pm8001_mpi_local_phy_ctl(struct pm8001_hba_info *pm8001_ha, void *piomb) -- 2.27.0
