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

[PanBian <bianpan2016@163.com>]

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 <bianpan2016@163.com>
> > Cc: stable@vger.kernel.org
> > ---
> > 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