drivers/misc/sgi-gru: fix possible NULL dereference

If mmu_find_ops() returns NULL then we are allocating memory for gms
using kzalloc. But kzalloc can return NULL and we were dereferencing gms
in gru_dbg().

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index 2129274..757a8e9 100644 (file)
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -317,8 +317,9 @@ struct gru_mm_struct *gru_register_mmu_notifier(void)
                                goto error;
                }
        }
-       gru_dbg(grudev, "gms %p, refcnt %d\n", gms,
-               atomic_read(&gms->ms_refcnt));
+       if (gms)
+               gru_dbg(grudev, "gms %p, refcnt %d\n", gms,
+                       atomic_read(&gms->ms_refcnt));
        return gms;
 error:
        kfree(gms);