2011-04-01 14:24:23

by Julia Lawall

Subject: [PATCH 5/6] drivers/scsi/bnx2fc/bnx2fc_hwi.c: introduce missing kfree

Error handling code following a kmalloc 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 <[email protected]>

---
drivers/scsi/bnx2fc/bnx2fc_hwi.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/bnx2fc/bnx2fc_hwi.c b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
index 1b680e2..f756d5f 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
@@ -522,6 +522,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
fp = fc_frame_alloc(lport, payload_len);
if (!fp) {
printk(KERN_ERR PFX "fc_frame_alloc failure\n");
+ kfree(unsol_els);
return;
}

@@ -547,6 +548,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
*/
printk(KERN_ERR PFX "dropping ELS 0x%x\n", op);
kfree_skb(skb);
+ kfree(unsol_els);
return;
}
}
@@ -563,6 +565,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
} else {
BNX2FC_HBA_DBG(lport, "fh_r_ctl = 0x%x\n", fh->fh_r_ctl);
kfree_skb(skb);
+ kfree(unsol_els);
}
}

2011-04-01 21:23:19

by Bhanu Prakash Gollapudi

Subject: Re: [PATCH 5/6] drivers/scsi/bnx2fc/bnx2fc_hwi.c: introduce missing kfree

On Fri, 2011-04-01 at 07:23 -0700, Julia Lawall wrote:
> Error handling code following a kmalloc 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 <[email protected]>

Thanks Julia.

Acked-by: Bhanu Prakash Gollapudi <[email protected]>

>
> ---
> drivers/scsi/bnx2fc/bnx2fc_hwi.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/scsi/bnx2fc/bnx2fc_hwi.c b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> index 1b680e2..f756d5f 100644
> --- a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> +++ b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> @@ -522,6 +522,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
> fp = fc_frame_alloc(lport, payload_len);
> if (!fp) {
> printk(KERN_ERR PFX "fc_frame_alloc failure\n");
> + kfree(unsol_els);
> return;
> }
>
> @@ -547,6 +548,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
> */
> printk(KERN_ERR PFX "dropping ELS 0x%x\n", op);
> kfree_skb(skb);
> + kfree(unsol_els);
> return;
> }
> }
> @@ -563,6 +565,7 @@ void bnx2fc_process_l2_frame_compl(struct bnx2fc_rport *tgt,
> } else {
> BNX2FC_HBA_DBG(lport, "fh_r_ctl = 0x%x\n", fh->fh_r_ctl);
> kfree_skb(skb);
> + kfree(unsol_els);
> }
> }
>
>
>