[PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[yu kuai]

commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug") add a
kree() for 'buf' if bio_integrity_add_page() return '0'. However, the
object will be freed in bio_integrity_free() since 'bio->bi_opf' and
'bio->bi_integrity' was set previousy in bio_integrity_alloc().

Fixes: commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug")
Signed-off-by: yu kuai <yukuai3@huawei.com>
---
 block/bio-integrity.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index bf62c25cde8f..ae07dd78e951 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -278,7 +278,6 @@ bool bio_integrity_prep(struct bio *bio)
 
 		if (ret == 0) {
 			printk(KERN_ERR "could not attach integrity payload\n");
-			kfree(buf);
 			status = BLK_STS_RESOURCE;
 			goto err_end_io;
 		}
-- 
2.25.4

Re: [PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[Ming Lei]

On Mon, Jun 01, 2020 at 08:38:56PM +0800, yu kuai wrote:
> commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug") add a
> kree() for 'buf' if bio_integrity_add_page() return '0'. However, the
> object will be freed in bio_integrity_free() since 'bio->bi_opf' and
> 'bio->bi_integrity' was set previousy in bio_integrity_alloc().
> 
> Fixes: commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug")
> Signed-off-by: yu kuai <yukuai3@huawei.com>
> ---
>  block/bio-integrity.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index bf62c25cde8f..ae07dd78e951 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -278,7 +278,6 @@ bool bio_integrity_prep(struct bio *bio)
>  
>  		if (ret == 0) {
>  			printk(KERN_ERR "could not attach integrity payload\n");
> -			kfree(buf);
>  			status = BLK_STS_RESOURCE;
>  			goto err_end_io;
>  		}

Looks correct, and it relies on the fact the 1st 'page' is always added
successfully, so 'buf' is always attached to the bip since then:

Reviewed-by: Ming Lei <ming.lei@redhat.com>


thanks, 
Ming

Re: [PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[Bob Liu]

On 6/1/20 8:38 PM, yu kuai wrote:
> commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug") add a
> kree() for 'buf' if bio_integrity_add_page() return '0'. However, the
> object will be freed in bio_integrity_free() since 'bio->bi_opf' and
> 'bio->bi_integrity' was set previousy in bio_integrity_alloc().
> 
> Fixes: commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug")
> Signed-off-by: yu kuai <yukuai3@huawei.com>> ---
>  block/bio-integrity.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index bf62c25cde8f..ae07dd78e951 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -278,7 +278,6 @@ bool bio_integrity_prep(struct bio *bio)
>  
>  		if (ret == 0) {
>  			printk(KERN_ERR "could not attach integrity payload\n");
> -			kfree(buf);
>  			status = BLK_STS_RESOURCE;
>  			goto err_end_io;
>  		}
> 

Looks good to me.
Reviewed-by: Bob Liu <bob.liu@oracle.com>

Re: [PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[Martin K. Petersen]

Hi Yu!

I suggest a few minor wording tweaks to the commit message:

> commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug") add

s/add/added/

> a kree() for 'buf' if bio_integrity_add_page() return '0'. However,
> the

s/kree/kfree/
s/return/returns/

> object will be freed in bio_integrity_free() since 'bio->bi_opf' and
> 'bio->bi_integrity' was set previousy in bio_integrity_alloc().

s/was/were/

Otherwise OK.

And like Ming pointed out, you may want to add a comment about the
assertion that the first vec is valid.

Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed

[Jens Axboe]

On 6/1/20 6:38 AM, yu kuai wrote:
> commit e7bf90e5afe3 ("block/bio-integrity: fix a memory leak bug") add a
> kree() for 'buf' if bio_integrity_add_page() return '0'. However, the
> object will be freed in bio_integrity_free() since 'bio->bi_opf' and
> 'bio->bi_integrity' was set previousy in bio_integrity_alloc().

Applied, thanks.

-- 
Jens Axboe