firmware: dmi_scan: Trim DMI table length before exporting it

The SMBIOS v3 entry points specify a maximum length for the DMI table,
not the exact length. Thus there may be garbage after the end-of-table
marker, which we don't want to export to user-space. Adjust dmi_len
when we find the end-of-table marker, so that only the actual table
payload is exported.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
This commit is contained in:
Jean Delvare 2015-06-25 09:06:56 +02:00
parent eb4c5ea50e
commit 6e0ad59e3d

View File

@ -108,6 +108,9 @@ static void dmi_decode_table(u8 *buf,
if (data - buf < dmi_len - 1)
decode(dm, private_data);
data += 2;
i++;
/*
* 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
* For tables behind a 64-bit entry point, we have no item
@ -118,10 +121,11 @@ static void dmi_decode_table(u8 *buf,
*/
if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
break;
data += 2;
i++;
}
/* Trim DMI table length if needed */
if (dmi_len > data - buf)
dmi_len = data - buf;
}
static phys_addr_t dmi_base;
@ -130,8 +134,9 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
void *))
{
u8 *buf;
u32 orig_dmi_len = dmi_len;
buf = dmi_early_remap(dmi_base, dmi_len);
buf = dmi_early_remap(dmi_base, orig_dmi_len);
if (buf == NULL)
return -1;
@ -139,7 +144,7 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
add_device_randomness(buf, dmi_len);
dmi_early_unmap(buf, dmi_len);
dmi_early_unmap(buf, orig_dmi_len);
return 0;
}