Re: [PATCH 6/10] drivers/net/wireless/iwlwifi: introduce missingkfree

From: Zhu Yi
Date: Sun Aug 02 2009 - 20:44:18 EST


On Sat, 2009-08-01 at 16:54 +0800, Julia Lawall wrote:
> From: Julia Lawall <julia@xxxxxxx>
>
> Error handling code following a kzalloc should free the allocated data.
>
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
>
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
>
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
> when != if (...) { <+...x...+> }
> (
> x->f1 = E
> |
> (x->f1 == NULL || ...)
> |
> f(...,x->f1,...)
> )
> ...>
> (
> return \(0\|<+...x...+>\|ptr\);
> |
> return@p2 ...;
> )
>
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
>
> print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@xxxxxxx>
> ---
> drivers/net/wireless/iwlwifi/iwl-debugfs.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
> index 7707a26..c2106d0 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
> @@ -320,6 +320,7 @@ static ssize_t iwl_dbgfs_nvm_read(struct file *file,
> ptr = priv->eeprom;
> if (!ptr) {
> IWL_ERR(priv, "Invalid EEPROM/OTP memory\n");
> + kfree(buf);
> return -ENOMEM;
> }
> pos += scnprintf(buf + pos, buf_size - pos, "NVM Type: %s\n",

Probably moving !priv->eeprom check prior to buf kzalloc is better.

Thanks,
-yi

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