[PATCH] ARM: mvebu: Add check in coherency.c to prevent null pointer dereference

[Duoming Zhou]

The kzalloc() in armada_375_380_coherency_init() will return
null if the physical memory has run out. As a result, if we
dereference the property pointer, the null pointer dereference
bug will happen.

This patch adds a check to avoid null pointer dereference.

Fixes: 497a92308af8 ("ARM: mvebu: implement L2/PCIe deadlock workaround")
Signed-off-by: Duoming Zhou <duoming at zju.edu.cn>
---
 arch/arm/mach-mvebu/coherency.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index a6b621ff0b8..a81a3c8c19a 100644
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -191,6 +191,8 @@ static void __init armada_375_380_coherency_init(struct device_node *np)
 		struct property *p;
 
 		p = kzalloc(sizeof(*p), GFP_KERNEL);
+		if (!p)
+			continue;
 		p->name = kstrdup("arm,io-coherent", GFP_KERNEL);
 		of_add_property(cache_dn, p);
 	}
-- 
2.17.1