2019-08-19 01:17:36

by Pan Bian

Subject: [PATCH V2] block/bio-integrity: fix mismatched alloc free

The function kmalloc rather than mempool_alloc is called to allocate
memory when the memory pool is unavailable. However, mempool_alloc is
used to release the memory chunck in both cases when error occurs. This
patch fixes the bug.

Fixes: 9f060e2231c ("block: Convert integrity to bvec_alloc_bs()")
Signed-off-by: Pan Bian <[email protected]>
Cc: [email protected]
---
V2: add Fixes and CC tags
---
block/bio-integrity.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index fb95dbb..011dfc8 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -75,7 +75,10 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,

return bip;
err:
- mempool_free(bip, &bs->bio_integrity_pool);
+ if (!bs || !mempool_initialized(&bs->bio_integrity_pool))
+ kfree(bip);
+ else
+ mempool_free(bip, &bs->bio_integrity_pool);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(bio_integrity_alloc);
--
2.7.4

2019-08-19 03:57:30

by Ming Lei

Subject: Re: [PATCH V2] block/bio-integrity: fix mismatched alloc free

On Mon, Aug 19, 2019 at 08:59:13AM +0800, Pan Bian wrote:
> The function kmalloc rather than mempool_alloc is called to allocate
> memory when the memory pool is unavailable. However, mempool_alloc is
> used to release the memory chunck in both cases when error occurs. This
> patch fixes the bug.
>
> Fixes: 9f060e2231c ("block: Convert integrity to bvec_alloc_bs()")
> Signed-off-by: Pan Bian <[email protected]>
> Cc: [email protected]
> ---
> V2: add Fixes and CC tags
> ---
> block/bio-integrity.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index fb95dbb..011dfc8 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -75,7 +75,10 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
>
> return bip;
> err:
> - mempool_free(bip, &bs->bio_integrity_pool);
> + if (!bs || !mempool_initialized(&bs->bio_integrity_pool))
> + kfree(bip);
> + else
> + mempool_free(bip, &bs->bio_integrity_pool);
> return ERR_PTR(-ENOMEM);
> }
> EXPORT_SYMBOL(bio_integrity_alloc);

'err' is still reached in case that 'bs' is valid, so fix nothing.


Thanks,
Ming

2019-08-19 04:16:07

by Pan Bian

Subject: Re: [PATCH V2] block/bio-integrity: fix mismatched alloc free

On Mon, Aug 19, 2019 at 11:56:14AM +0800, Ming Lei wrote:
> On Mon, Aug 19, 2019 at 08:59:13AM +0800, Pan Bian wrote:
> > The function kmalloc rather than mempool_alloc is called to allocate
> > memory when the memory pool is unavailable. However, mempool_alloc is
> > used to release the memory chunck in both cases when error occurs. This
> > patch fixes the bug.
> >
> > Fixes: 9f060e2231c ("block: Convert integrity to bvec_alloc_bs()")
> > Signed-off-by: Pan Bian <[email protected]>
> > Cc: [email protected]
> > ---
> > V2: add Fixes and CC tags
> > ---
> > block/bio-integrity.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> > index fb95dbb..011dfc8 100644
> > --- a/block/bio-integrity.c
> > +++ b/block/bio-integrity.c
> > @@ -75,7 +75,10 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
> >
> > return bip;
> > err:
> > - mempool_free(bip, &bs->bio_integrity_pool);
> > + if (!bs || !mempool_initialized(&bs->bio_integrity_pool))
> > + kfree(bip);
> > + else
> > + mempool_free(bip, &bs->bio_integrity_pool);
> > return ERR_PTR(-ENOMEM);
> > }
> > EXPORT_SYMBOL(bio_integrity_alloc);
>
> 'err' is still reached in case that 'bs' is valid, so fix nothing.

You are right! It's my fault.

Thanks,
Pan

>
>
> Thanks,
> Ming