scsi: arcmsr: Simplify user_len checking

Do the user_len check first and then the ver_addr allocation so that we
can save us the kfree() on the error path when user_len is >
ARCMSR_API_DATA_BUFLEN.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Marco Grassi <marco.gra@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tomas Henzl <thenzl@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 4bd173c30792791a6daca8c64793ec0a4ae8324f)

Orabug: 24710898
CVE-2016-7425

Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 858f88a6a351055ae47f24eb4804df9c5b15a0c5..1161d152a57a5d98697f019c0122ad4d8178ef10 100644 (file)
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2303,18 +2303,20 @@ static int arcmsr_iop_message_xfer(struct AdapterControlBlock *acb,
                uint32_t user_len;
                int32_t cnt2end;
                uint8_t *pQbuffer, *ptmpuserbuffer;
-               ver_addr = kmalloc(ARCMSR_API_DATA_BUFLEN, GFP_ATOMIC);
-               if (!ver_addr) {
+
+               user_len = pcmdmessagefld->cmdmessage.Length;
+               if (user_len > ARCMSR_API_DATA_BUFLEN) {
                        retvalue = ARCMSR_MESSAGE_FAIL;
                        goto message_out;
                }
-               ptmpuserbuffer = ver_addr;
-               user_len = pcmdmessagefld->cmdmessage.Length;
-               if (user_len > ARCMSR_API_DATA_BUFLEN) {
+
+               ver_addr = kmalloc(ARCMSR_API_DATA_BUFLEN, GFP_ATOMIC);
+               if (!ver_addr) {
                        retvalue = ARCMSR_MESSAGE_FAIL;
-                       kfree(ver_addr);
                        goto message_out;
                }
+               ptmpuserbuffer = ver_addr;
+
                memcpy(ptmpuserbuffer,
                        pcmdmessagefld->messagedatabuffer, user_len);
                spin_lock_irqsave(&acb->wqbuffer_lock, flags);