Re: [PATCH RESEND 04/10] crypto: hisilicon/zip - replace 'sprintf' with 'scnprintf'

[shenyang (M)]

On 2020/8/24 16:29, David Laight wrote:
> From: Yang Shen
> > Sent: 24 August 2020 04:12
> >
> > Replace 'sprintf' with 'scnprintf' to avoid overrun.
> >
> > Signed-off-by: Yang Shen <shenyang39@xxxxxxxxxx>
> > Reviewed-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
> > ---
> >  drivers/crypto/hisilicon/zip/zip_main.c | 11 +++++++----
> >  1 file changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/crypto/hisilicon/zip/zip_main.c b/drivers/crypto/hisilicon/zip/zip_main.c
> > index df1a16f..1883d1b 100644
> > --- a/drivers/crypto/hisilicon/zip/zip_main.c
> > +++ b/drivers/crypto/hisilicon/zip/zip_main.c
> > @@ -428,7 +428,7 @@ static ssize_t hisi_zip_ctrl_debug_read(struct file *filp, char __user *buf,
> >  		return -EINVAL;
> >  	}
> >  	spin_unlock_irq(&file->lock);
> > -	ret = sprintf(tbuf, "%u\n", val);
> > +	ret = scnprintf(tbuf, HZIP_BUF_SIZE, "%u\n", val);
>
> Should that be sizeof (tbuf).
>
> >  	return simple_read_from_buffer(buf, count, pos, tbuf, ret);
> >  }
> >
> > @@ -514,13 +514,16 @@ static int hisi_zip_core_debug_init(struct hisi_qm *qm)
> >  	struct debugfs_regset32 *regset;
> >  	struct dentry *tmp_d;
> >  	char buf[HZIP_BUF_SIZE];
> > -	int i;
> > +	int i, ret;
> >
> >  	for (i = 0; i < HZIP_CORE_NUM; i++) {
> >  		if (i < HZIP_COMP_CORE_NUM)
> > -			sprintf(buf, "comp_core%d", i);
> > +			ret = scnprintf(buf, HZIP_BUF_SIZE, "comp_core%d", i);
> >  		else
> > -			sprintf(buf, "decomp_core%d", i - HZIP_COMP_CORE_NUM);
> > +			ret = scnprintf(buf, HZIP_BUF_SIZE, "decomp_core%d",
> > +					i - HZIP_COMP_CORE_NUM);
> > +		if (!ret)
> > +			return -ENOMEM;
>
> and that is just so wrong - did you even try to test
> the 'buffer too small' code path?
>
> 	David

Do you means the check is unnecessary?

Yang
> -
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> Registration No: 1397386 (Wales)
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>
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