Messages in this thread | | | Subject | Re: [PATCH 1/4] platform/x86: simatic-ipc: add main driver for Siemens devices | From | Hans de Goede <> | Date | Thu, 4 Mar 2021 15:03:43 +0100 |
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Hi,
On 3/2/21 5:33 PM, Henning Schild wrote:
<snip>
> +static inline u32 simatic_ipc_get_station_id(u8 *data) > +{ > + u32 station_id = SIMATIC_IPC_INVALID_STATION_ID; > + int i; > + struct { > + u8 type; /* type (0xff = binary) */ > + u8 len; /* len of data entry */ > + u8 reserved[3]; > + u32 station_id; /* station id (LE) */ > + } __packed * data_entry = (void *)data; > + > + /* find 4th entry in OEM data */ > + for (i = 0; i < 3; i++) > + data_entry = (void *)((u8 *)(data_entry) + data_entry->len); > + > + /* decode station id */ > + if (data_entry && data_entry->type == 0xff && data_entry->len == 9) > + station_id = le32_to_cpu(data_entry->station_id); > + > + return station_id; > +} > + > +static inline void > +simatic_ipc_find_dmi_entry_helper(const struct dmi_header *dh, void *_data) > +{ > + u32 *id = _data; > + > + if (dh->type != DMI_ENTRY_OEM) > + return; > + > + *id = simatic_ipc_get_station_id((u8 *)dh + sizeof(struct dmi_header)); > +}
Please take dh->length into account here and make sure that you don't walk past the end of the DMI tables during the parsing here.
Regards,
Hans
> + > +#endif /* __PLATFORM_DATA_X86_SIMATIC_IPC_H */ >
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