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 <[email protected]>
>> Reviewed-by: Zhou Wang <[email protected]>
>> ---
>> 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
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>
>
> .
>
On Wed, Aug 26, 2020 at 04:56:40PM +0800, shenyang (M) wrote:
>
> > > @@ -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?
>
> Do you means the check is unnecessary?
No he's saying that your patch does the wrong thing when the string
is truncated.
Also ENOMEM is a strange error for that case.
Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt