Messages in this thread | | | Subject | Re: [PATCH net-next v1 5/5] hinic: add support to get eeprom information | From | "luobin (L)" <> | Date | Mon, 22 Jun 2020 10:05:06 +0800 |
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On 2020/6/21 0:00, Andrew Lunn wrote: >> +static int hinic_get_module_eeprom(struct net_device *netdev, >> + struct ethtool_eeprom *ee, u8 *data) >> +{ >> + struct hinic_dev *nic_dev = netdev_priv(netdev); >> + u8 sfp_data[STD_SFP_INFO_MAX_SIZE]; > > sfp_data will contain whatever is on the stack. > >> + u16 len; >> + int err; >> + >> + if (!ee->len || ((ee->len + ee->offset) > STD_SFP_INFO_MAX_SIZE)) >> + return -EINVAL; >> + >> + memset(data, 0, ee->len); > > This clears what you are going to return. > >> + >> + err = hinic_get_sfp_eeprom(nic_dev->hwdev, sfp_data, &len); > > Upto len bytes of sfp_data now contain useful data. The rest of > sfp_data is still stack data. > > >> + if (err) >> + return err; >> + >> + memcpy(data, sfp_data + ee->offset, ee->len); > > If len < ee->len, you have just returned to user space some stack data. > > Andrew > . > The whole sfp_data will be assigned values in hinic_get_sfp_eeprom function, so stack data won't be returned to user space. Thanks for your review.
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