[PATCH] net/802: use struct_size over open coded arithmetic

* [PATCH] net/802: use struct_size over open coded arithmetic
@ 2022-01-28  8:05 cgel.zte
  2022-01-28 12:40 ` kernel test robot
  2022-01-28 12:51 ` kernel test robot
  0 siblings, 2 replies; 3+ messages in thread
From: cgel.zte @ 2022-01-28  8:05 UTC (permalink / raw)
  To: davem; +Cc: kuba, netdev, linux-kernel, Minghao Chi, Zeal Robot

From: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>

Replace zero-length array with flexible-array member and make use
of the struct_size() helper in kmalloc(). For example:

struct garp_attr {
	struct rb_node			node;
	enum garp_applicant_state	state;
	u8				type;
	u8				dlen;
	unsigned char			data[];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
---
 net/802/garp.c | 2 +-
 net/802/mrp.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/802/garp.c b/net/802/garp.c
index f6012f8e59f0..746763a76f83 100644
--- a/net/802/garp.c
+++ b/net/802/garp.c
@@ -184,7 +184,7 @@ static struct garp_attr *garp_attr_create(struct garp_applicant *app,
 			return attr;
 		}
 	}
-	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	attr = kmalloc(struct_size(*attr, data, len), GFP_ATOMIC);
 	if (!attr)
 		return attr;
 	attr->state = GARP_APPLICANT_VO;
diff --git a/net/802/mrp.c b/net/802/mrp.c
index 35e04cc5390c..ce3f1b610a3f 100644
--- a/net/802/mrp.c
+++ b/net/802/mrp.c
@@ -273,7 +273,7 @@ static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
 			return attr;
 		}
 	}
-	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	attr = kmalloc(struct_size(*attr, value, len), GFP_ATOMIC);
 	if (!attr)
 		return attr;
 	attr->state = MRP_APPLICANT_VO;
-- 
2.25.1


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