[PATCH] nbd: fix possible memory leak

[PATCH] nbd: fix possible memory leak

[Sudip Mukherjee]

we have already allocated memory for nbd_dev, but we were not
releasing that memory and just returning the error value.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---

Hi Paul,
after seeing your mail about maintainers, just started to see the code.
this patch is one way, another way can be to bring the kcalloc part below these checks. 

 drivers/block/nbd.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 4bc2a5c..13ea239 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -822,11 +822,15 @@ static int __init nbd_init(void)
 		max_part = (1UL << part_shift) - 1;
 	}
 
-	if ((1UL << part_shift) > DISK_MAX_PARTS)
-		return -EINVAL;
+	if ((1UL << part_shift) > DISK_MAX_PARTS) {
+		err = -EINVAL;
+		goto out_free;
+	}
 
-	if (nbds_max > 1UL << (MINORBITS - part_shift))
-		return -EINVAL;
+	if (nbds_max > 1UL << (MINORBITS - part_shift)) {
+		err = -EINVAL;
+		goto out_free;
+	}
 
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = alloc_disk(1 << part_shift);
@@ -889,6 +893,7 @@ out:
 		blk_cleanup_queue(nbd_dev[i].disk->queue);
 		put_disk(nbd_dev[i].disk);
 	}
+out_free:
 	kfree(nbd_dev);
 	return err;
 }
-- 
1.8.1.2

Re: [PATCH] nbd: fix possible memory leak

[Paul Clements]

Sudip,

On Tue, Jan 13, 2015 at 12:19 PM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> we have already allocated memory for nbd_dev, but we were not
> releasing that memory and just returning the error value.
>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
>
> Hi Paul,
> after seeing your mail about maintainers, just started to see the code.
> this patch is one way, another way can be to bring the kcalloc part below these checks.

Probably better to move the kcalloc below, rather than adding more
branches, wouldn't you agree?

Thanks,
Paul

[PATCH] nbd: fix possible memory leak

[Markus Pargmann]

From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>

we have already allocated memory for nbd_dev, but we were not
releasing that memory and just returning the error value.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Acked-by: Paul Clements <Paul.Clements@SteelEye.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/block/nbd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 4bc2a5cb9935..a98c41f72c63 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -803,10 +803,6 @@ static int __init nbd_init(void)
 		return -EINVAL;
 	}
 
-	nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
-	if (!nbd_dev)
-		return -ENOMEM;
-
 	part_shift = 0;
 	if (max_part > 0) {
 		part_shift = fls(max_part);
@@ -828,6 +824,10 @@ static int __init nbd_init(void)
 	if (nbds_max > 1UL << (MINORBITS - part_shift))
 		return -EINVAL;
 
+	nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
+	if (!nbd_dev)
+		return -ENOMEM;
+
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = alloc_disk(1 << part_shift);
 		if (!disk)
-- 
2.1.4

[PATCH] nbd: fix possible memory leak

[Markus Pargmann]

From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>

we have already allocated memory for nbd_dev, but we were not
releasing that memory and just returning the error value.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Acked-by: Paul Clements <Paul.Clements@SteelEye.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/block/nbd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 4bc2a5cb9935..a98c41f72c63 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -803,10 +803,6 @@ static int __init nbd_init(void)
 		return -EINVAL;
 	}
 
-	nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
-	if (!nbd_dev)
-		return -ENOMEM;
-
 	part_shift = 0;
 	if (max_part > 0) {
 		part_shift = fls(max_part);
@@ -828,6 +824,10 @@ static int __init nbd_init(void)
 	if (nbds_max > 1UL << (MINORBITS - part_shift))
 		return -EINVAL;
 
+	nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
+	if (!nbd_dev)
+		return -ENOMEM;
+
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = alloc_disk(1 << part_shift);
 		if (!disk)
-- 
2.1.4