2022-10-22 01:56:20

by Yu Kuai

Subject: [PATCH v2] block: fix memory leak for elevator on add_disk failure

From: Yu Kuai <[email protected]>

The default elevator is allocated in the beginning of device_add_disk(),
however, it's not freed in the following error path.

Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
---
Changes in v2:
- fix wrong fix tag
- add review tag

block/genhd.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index b3d04e79e854..fea319c8f99e 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -437,9 +437,10 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
* Otherwise just allocate the device numbers for both the whole device
* and all partitions from the extended dev_t space.
*/
+ ret = -EINVAL;
if (disk->major) {
if (WARN_ON(!disk->minors))
- return -EINVAL;
+ goto out_exit_elevator;

if (disk->minors > DISK_MAX_PARTS) {
pr_err("block: can't allocate more than %d partitions\n",
@@ -447,14 +448,14 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
disk->minors = DISK_MAX_PARTS;
}
if (disk->first_minor + disk->minors > MINORMASK + 1)
- return -EINVAL;
+ goto out_exit_elevator;
} else {
if (WARN_ON(disk->minors))
- return -EINVAL;
+ goto out_exit_elevator;

ret = blk_alloc_ext_minor();
if (ret < 0)
- return ret;
+ goto out_exit_elevator;
disk->major = BLOCK_EXT_MAJOR;
disk->first_minor = ret;
}
@@ -571,6 +572,9 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
out_free_ext_minor:
if (disk->major == BLOCK_EXT_MAJOR)
blk_free_ext_minor(disk->first_minor);
+out_exit_elevator:
+ if (disk->queue->elevator)
+ elevator_exit(disk->queue);
return ret;
}
EXPORT_SYMBOL(device_add_disk);
--
2.31.1

2022-10-22 11:20:30

by Jason Yan

Subject: Re: [PATCH v2] block: fix memory leak for elevator on add_disk failure

On 2022/10/22 10:16, Yu Kuai wrote:
> From: Yu Kuai<[email protected]>
>
> The default elevator is allocated in the beginning of device_add_disk(),
> however, it's not freed in the following error path.
>
> Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
> Signed-off-by: Yu Kuai<[email protected]>
> Reviewed-by: Christoph Hellwig<[email protected]>
> ---
> Changes in v2:
> - fix wrong fix tag
> - add review tag
>
> block/genhd.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)

Reviewed-by: Jason Yan <[email protected]>

2022-10-22 21:37:40

by Jens Axboe

Subject: Re: [PATCH v2] block: fix memory leak for elevator on add_disk failure

On Sat, 22 Oct 2022 10:16:15 +0800, Yu Kuai wrote:
> From: Yu Kuai <[email protected]>
>
> The default elevator is allocated in the beginning of device_add_disk(),
> however, it's not freed in the following error path.
>
>

Applied, thanks!

[1/1] block: fix memory leak for elevator on add_disk failure
commit: 02341a08c9dec5a88527981b0bdf0fb6f7499cbf

Best regards,
--
Jens Axboe