scsi: arcmsr: Buffer overflow in arcmsr_iop_message_xfer()

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

Cc: <stable@vger.kernel.org>
Reported-by: Marco Grassi <marco.gra@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 7640498964a5..110eca9eaca0 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2388,7 +2388,8 @@ static int arcmsr_iop_message_xfer(struct AdapterControlBlock *acb,
         }
         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(struct AdapterControlBlock *acb,
                 }
                 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);