[S390] dasd: security and PSF update patch for EMC CKD ioctl

Remove the PSF order/suborder check from the Symmetrix CKD dasd ioctl.
In exchange restrict the ioctl to CAP_SYS_ADMIN and CAP_SYS_RAWIO.

Signed-off-by: Nigel Hislop <hislop_nigel@emc.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 1cca21aafaba..d7163f904f40 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2839,8 +2839,13 @@ static int dasd_symm_io(struct dasd_device *device, void __user *argp)
         char *psf_data, *rssd_result;
         struct dasd_ccw_req *cqr;
         struct ccw1 *ccw;
+        char psf0, psf1;
         int rc;
 
+        if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+                return -EACCES;
+        psf0 = psf1 = 0;
+
         /* Copy parms from caller */
         rc = -EFAULT;
         if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
@@ -2869,12 +2874,8 @@ static int dasd_symm_io(struct dasd_device *device, void __user *argp)
                            (void __user *)(unsigned long) usrparm.psf_data,
                            usrparm.psf_data_len))
                 goto out_free;
-
-        /* sanity check on syscall header */
-        if (psf_data[0] != 0x17 && psf_data[1] != 0xce) {
-                rc = -EINVAL;
-                goto out_free;
-        }
+        psf0 = psf_data[0];
+        psf1 = psf_data[1];
 
         /* setup CCWs for PSF + RSSD */
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 , 0, device);
@@ -2925,7 +2926,9 @@ out_free:
         kfree(rssd_result);
         kfree(psf_data);
 out:
-        DBF_DEV_EVENT(DBF_WARNING, device, "Symmetrix ioctl: rc=%d", rc);
+        DBF_DEV_EVENT(DBF_WARNING, device,
+                      "Symmetrix ioctl (0x%02x 0x%02x): rc=%d",
+                      (int) psf0, (int) psf1, rc);
         return rc;
 }