From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Thu, 10 Sep 2015 10:52:03 +0000 (+0530)
Subject: drivers/misc/sgi-gru: fix possible NULL dereference
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f97ef759999485df485fe19a440d6af02d561140;p=linux-beck.git

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 2129274ef7ab..757a8e9aabdb 100644
--- 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);