[PATCH 4.8 35/57] scsi: arcmsr: Buffer overflow in arcmsr_iop_message_xfer()

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpen...@oracle.com>

commit 7bc2b55a5c030685b399bb65b6baa9ccc3d1f167 upstream.

We need to put an upper bound on "user_len" so the memcpy() doesn't
overflow.

Reported-by: Marco Grassi <marco....@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
Reviewed-by: Tomas Henzl <the...@redhat.com>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/scsi/arcmsr/arcmsr_hba.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2388,7 +2388,8 @@ static int arcmsr_iop_message_xfer(struc
        }
        case ARCMSR_MESSAGE_WRITE_WQBUFFER: {
                unsigned char *ver_addr;
-               int32_t user_len, cnt2end;
+               uint32_t user_len;
+               int32_t cnt2end;
                uint8_t *pQbuffer, *ptmpuserbuffer;
                ver_addr = kmalloc(ARCMSR_API_DATA_BUFLEN, GFP_ATOMIC);
                if (!ver_addr) {
@@ -2397,6 +2398,11 @@ static int arcmsr_iop_message_xfer(struc
                }
                ptmpuserbuffer = ver_addr;
                user_len = pcmdmessagefld->cmdmessage.Length;
+               if (user_len > ARCMSR_API_DATA_BUFLEN) {
+                       retvalue = ARCMSR_MESSAGE_FAIL;
+                       kfree(ver_addr);
+                       goto message_out;
+               }
                memcpy(ptmpuserbuffer,
                        pcmdmessagefld->messagedatabuffer, user_len);
                spin_lock_irqsave(&acb->wqbuffer_lock, flags);