[PATCH 1/5] drivers/net/irda: Eliminate memory leak

From: Julia Lawall
Date: Tue Aug 24 2010 - 10:38:47 EST


From: Julia Lawall <julia@xxxxxxx>

dev_alloc_skb allocates some memory, so that memory should be freed before
leaving the function in an error case.

Corrected some typos in a nearby comment as well.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression x;
expression E;
identifier f1;
iterator I;
@@

x = dev_alloc_skb(...);
<... when != x
when != true (x == NULL || ...)
when != if (...) { <+...x...+> }
when != I (...) { <+...x...+> }
(
x == NULL
|
x == E
|
x->f1
)
...>
* return ...;
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/net/irda/via-ircc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/irda/via-ircc.c b/drivers/net/irda/via-ircc.c
index b0a6cd8..67c0ad4 100644
--- a/drivers/net/irda/via-ircc.c
+++ b/drivers/net/irda/via-ircc.c
@@ -1182,12 +1182,13 @@ F01_E */

skb = dev_alloc_skb(len + 1 - 4);
/*
- * if frame size,data ptr,or skb ptr are wrong ,the get next
+ * if frame size, data ptr, or skb ptr are wrong, then get next
* entry.
*/
if ((skb == NULL) || (skb->data == NULL) ||
(self->rx_buff.data == NULL) || (len < 6)) {
self->netdev->stats.rx_dropped++;
+ kfree_skb(skb);
return TRUE;
}
skb_reserve(skb, 1);
--
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