s390/vmlogrdr: fix IUCV buffer allocation
authorGerald Schaefer <gerald.schaefer@de.ibm.com>
Mon, 21 Nov 2016 11:13:58 +0000 (12:13 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Mon, 12 Dec 2016 08:01:25 +0000 (09:01 +0100)
The buffer for iucv_message_receive() needs to be below 2 GB. In
__iucv_message_receive(), the buffer address is casted to an u32, which
would result in either memory corruption or an addressing exception when
using addresses >= 2 GB.

Fix this by using GFP_DMA for the buffer allocation.

Cc: stable@vger.kernel.org
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/char/vmlogrdr.c

index e883063..3167e85 100644 (file)
@@ -870,7 +870,7 @@ static int __init vmlogrdr_init(void)
                goto cleanup;
 
        for (i=0; i < MAXMINOR; ++i ) {
-               sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL);
+               sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
                if (!sys_ser[i].buffer) {
                        rc = -ENOMEM;
                        break;