scsi: arcmsr: Buffer overflow in arcmsr_iop_message_xfer()

[ Upstream commit 7bc2b55a5c030685b399bb65b6baa9ccc3d1f167 ]

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

References: CVE-2016-7425
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>
Signed-off-by: Philipp Hahn <hahn@univention.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 2926295a936de7c16c5e8cb4ed5729a98c7dfb24..c9f87cdc85c1dc07debe93169f857c67dbcbfe39 100644 (file)
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2300,7 +2300,8 @@ 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) {
@@ -2309,6 +2310,11 @@ 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);