2009-08-06 20:05:18

by Julia Lawall

Subject: [PATCH 2/3] drivers/bluetooth: Add kmalloc NULL tests

From: Julia Lawall <[email protected]>

Check that the result of kmalloc is not NULL before dereferencing it.
The patch also replaces kmalloc + memset by kzalloc.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression *x;
identifier f;
constant char *C;
@@

x = \(kmalloc\|kcalloc\|kzalloc\)(...);
... when != x == NULL
when != x != NULL
when != (x || ...)
(
kfree(x)
|
f(...,C,...,x,...)
|
*f(...,x,...)
|
*x->f
)
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
drivers/bluetooth/btmrvl_sdio.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btmrvl_sdio.c b/drivers/bluetooth/btmrvl_sdio.c
index 1cfa8b4..5b33b85 100644
--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -777,10 +777,11 @@ static int btmrvl_sdio_host_to_card(struct btmrvl_private *priv,
buf = payload;
if ((unsigned long) payload & (BTSDIO_DMA_ALIGN - 1)) {
tmpbufsz = ALIGN_SZ(nb, BTSDIO_DMA_ALIGN);
- tmpbuf = kmalloc(tmpbufsz, GFP_KERNEL);
- memset(tmpbuf, 0, tmpbufsz);
+ tmpbuf = kzalloc(tmpbufsz, GFP_KERNEL);
+ if (!tmpbuf)
+ return -ENOMEM;
buf = (u8 *) ALIGN_ADDR(tmpbuf, BTSDIO_DMA_ALIGN);
memcpy(buf, payload, nb);
}

2009-08-06 20:14:02

by Marcel Holtmann

Subject: Re: [PATCH 2/3] drivers/bluetooth: Add kmalloc NULL tests

Hi Julia,

> From: Julia Lawall <[email protected]>
>
> Check that the result of kmalloc is not NULL before dereferencing it.
> The patch also replaces kmalloc + memset by kzalloc.

good that this driver is not merged upstream yet. I apply the patch to
my tree. Thanks.

Regards

Marcel