[PATCH] drivers/misc/sgi-gru: fix possible NULL dereference

From: Sudip Mukherjee
Date: Thu Sep 10 2015 - 06:52:19 EST


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@xxxxxxxxxxxxxxx>
---
drivers/misc/sgi-gru/grutlbpurge.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index 2129274..757a8e9 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);
--
1.9.1

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