From: yuuzheng <yuuzheng@xxxxxxxxxx>
The use-after-free or null-pointer error occurs when the 251-byte
response data are copied from IOMB buffer to response message
buffer in function mp8001_mpi_set_nvmd_resp. pm8001_mpi_set_nvmd_resp
is a function to process the response of command set_nvmd_data_resp.
After sending the command set_nvmd_data, the caller begins to sleep by
calling wait_for_complete() and wait for the wake-up from calling
complete() in pm8001_mpi_set_nvmd_resp. In the current code,
the memcpy for response message buffer occurs after calling complete().
So, it is not protected by the use of wait_for_completion() and
complete().
Due to unexpected events (e.g., interrupt), if response buffer gets
freed before memcpy, the use-after-free error will occur.
To fix it, the complete() should be called after memcpy.
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>
---
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 9e9a546da959..2054c2b03d92 100644
--- a/drivers/scsi/pm8001/pm8001_hwi.c
+++ b/drivers/scsi/pm8001/pm8001_hwi.c
@@ -3279,10 +3279,15 @@ 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)
--
2.16.3
