[PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[Jesper Juhl]

There is a memory leak in tcm_loop_make_scsi_hba().

If all the strstr() calls return NULL and we end up at
 return ERR_PTR(-EINVAL);
then we'll be leaking the memory previously allocated to tl_hba as
that variable goes out of scope.

This patch should fix the leak.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 drivers/target/loopback/tcm_loop.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

  Compile tested only.
  Last submitted April 07, 2011

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 70c2e7f..aa3bb70 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -1321,7 +1321,8 @@ struct se_wwn *tcm_loop_make_scsi_hba(
 
 	printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
 			" %s\n", name);
-	return ERR_PTR(-EINVAL);
+	ret = -EINVAL;
+	goto out;
 
 check_len:
 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
-- 
1.7.5.2


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
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Re: [PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[Dan Carpenter]

On Mon, Jun 27, 2011 at 11:54:48PM +0200, Jesper Juhl wrote:
> --- a/drivers/target/loopback/tcm_loop.c
> +++ b/drivers/target/loopback/tcm_loop.c
> @@ -1321,7 +1321,8 @@ struct se_wwn *tcm_loop_make_scsi_hba(
>  
>  	printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
>  			" %s\n", name);
> -	return ERR_PTR(-EINVAL);
> +	ret = -EINVAL;
> +	goto out;

You've added a weird bunny hop goto here.  It might be better to
change the if (ptr) check to if (!ptr) so we could fall through
here in the normal case.

>  
>  check_len:
>  	if (strlen(name) >= TL_WWN_ADDR_LEN) {

If this check fails then it calls kfree() and returns.  It would be
cleaner to "goto out" here as well.

regards,
dan carpenter

Re: [PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[Jesper Juhl]

On Tue, 28 Jun 2011, Dan Carpenter wrote:

> On Mon, Jun 27, 2011 at 11:54:48PM +0200, Jesper Juhl wrote:
> > --- a/drivers/target/loopback/tcm_loop.c
> > +++ b/drivers/target/loopback/tcm_loop.c
> > @@ -1321,7 +1321,8 @@ struct se_wwn *tcm_loop_make_scsi_hba(
> >  
> >  	printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
> >  			" %s\n", name);
> > -	return ERR_PTR(-EINVAL);
> > +	ret = -EINVAL;
> > +	goto out;
> 
> You've added a weird bunny hop goto here.  It might be better to
> change the if (ptr) check to if (!ptr) so we could fall through
> here in the normal case.
> 
> >  
> >  check_len:
> >  	if (strlen(name) >= TL_WWN_ADDR_LEN) {
> 
> If this check fails then it calls kfree() and returns.  It would be
> cleaner to "goto out" here as well.
> 

You mean like this - right?

---

There is a memory leak in tcm_loop_make_scsi_hba().

If all the strstr() calls return NULL and we end up at
 return ERR_PTR(-EINVAL);
then we'll be leaking the memory previously allocated to tl_hba as
that variable goes out of scope.

This patch should fix the leak.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 drivers/target/loopback/tcm_loop.c |   17 ++++++++---------
 1 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 70c2e7f..e7a32e9 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -1314,22 +1314,21 @@ struct se_wwn *tcm_loop_make_scsi_hba(
 		goto check_len;
 	}
 	ptr = strstr(name, "iqn.");
-	if (ptr) {
-		tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
-		goto check_len;
+	if (!ptr) {
+		printk(KERN_ERR "Unable to locate prefix for emulated Target "
+				"Port: %s\n", name);
+		ret = -EINVAL;
+		goto out;
 	}
-
-	printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
-			" %s\n", name);
-	return ERR_PTR(-EINVAL);
+	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
 
 check_len:
 	if (strlen(name) >= TL_WWN_ADDR_LEN) {
 		printk(KERN_ERR "Emulated NAA %s Address: %s, exceeds"
 			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
 			TL_WWN_ADDR_LEN);
-		kfree(tl_hba);
-		return ERR_PTR(-EINVAL);
+		ret = -EINVAL;
+		goto out;
 	}
 	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
 
-- 
1.7.5.2


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[Dan Carpenter]

On Tue, Jun 28, 2011 at 12:30:17AM +0200, Jesper Juhl wrote:
> 
> You mean like this - right?

Yeah.

Acked-by: Dan Carpenter <error27@gmail.com>

regards,
dan carpenter

Re: [PATCH][Resend] SCSI, target, loopback: Fix memory leak in tcm_loop_make_scsi_hba()

[Nicholas A. Bellinger]

On Tue, 2011-06-28 at 09:22 +0300, Dan Carpenter wrote:
> On Tue, Jun 28, 2011 at 12:30:17AM +0200, Jesper Juhl wrote:
> > 
> > You mean like this - right?
> 
> Yeah.
> 
> Acked-by: Dan Carpenter <error27@gmail.com>
> 

Hi Guys,

Following up on some items that where missed over my summer holiday.

Committed and pushed this patch into lio-core-2.6.git/master recently as
the following.

Thanks JesperJ and DanC!

--nab

--------------------------------------------------------------------

commit 90e104e39aa30437a8ac4572e4499e7c3a914458
Author: Jesper Juhl <jj@chaosbits.net>
Date:   Tue Jun 28 00:30:17 2011 +0200

    loopback: Fix memory leak in tcm_loop_make_scsi_hba()
    
    There is a memory leak in tcm_loop_make_scsi_hba().
    
    If all the strstr() calls return NULL and we end up at return ERR_PTR(-EINVAL);
    then we'll be leaking the memory previously allocated to tl_hba as
    that variable goes out of scope.
    
    This patch should fix the leak.
    
    Signed-off-by: Jesper Juhl <jj@chaosbits.net>
    Signed-off-by: Dan Carpenter <error27@gmail.com>
    Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 5075e9b..f603698 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -1288,22 +1288,21 @@ struct se_wwn *tcm_loop_make_scsi_hba(
                goto check_len;
        }
        ptr = strstr(name, "iqn.");
-       if (ptr) {
-               tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
-               goto check_len;
+       if (!ptr) {
+               printk(KERN_ERR "Unable to locate prefix for emulated Target "
+                               "Port: %s\n", name);
+               ret = -EINVAL;
+               goto out;
        }
-
-       printk(KERN_ERR "Unable to locate prefix for emulated Target Port:"
-                       " %s\n", name);
-       return ERR_PTR(-EINVAL);
+       tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
 
 check_len:
        if (strlen(name) >= TL_WWN_ADDR_LEN) {
                printk(KERN_ERR "Emulated NAA %s Address: %s, exceeds"
                        " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
                        TL_WWN_ADDR_LEN);
-               kfree(tl_hba);
-               return ERR_PTR(-EINVAL);
+               ret = -EINVAL;
+               goto out;
        }
        snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);