[dmidecode] [PATCH] dmidecode: Set vendor early

[Jean Delvare]

If OEM type entries come before the type 1 entry (System
Information), we aren't able to decode them because we don't know
the vendor yet. To fix this, figure out the vendor during a first
pass, and walk the table again once we have the information.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reported-by: Erwan Velu <e.velu@criteo.com>
---
 dmidecode.c |   50 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 45 insertions(+), 5 deletions(-)

--- dmidecode.orig/dmidecode.c  2021-01-05 12:45:19.744939071 +0100
+++ dmidecode/dmidecode.c       2021-01-05 12:50:22.518420537 +0100
@@ -5182,6 +5182,51 @@ static void dmi_table_decode(u8 *buf, u3
        u8 *data;
        int i = 0;
 
+       /* First pass: Save the vendor so that so that we can decode OEM types 
*/
+       data = buf;
+       while ((i < num || !num)
+           && data + 4 <= buf + len) /* 4 is the length of an SMBIOS structure 
header */
+       {
+               u8 *next;
+               struct dmi_header h;
+
+               to_dmi_header(&h, data);
+
+               /*
+                * If a short entry is found (less than 4 bytes), not only it
+                * is invalid, but we cannot reliably locate the next entry.
+                * Also stop at end-of-table marker if so instructed.
+                */
+               if (h.length < 4 ||
+                   (h.type == 127 &&
+                    (opt.flags & (FLAG_QUIET | FLAG_STOP_AT_EOT))))
+                       break;
+               i++;
+
+               /* Look for the next handle */
+               next = data + h.length;
+               while ((unsigned long)(next - buf + 1) < len
+                   && (next[0] != 0 || next[1] != 0))
+                       next++;
+               next += 2;
+
+               /* Make sure the whole structure fits in the table */
+               if ((unsigned long)(next - buf) > len)
+                       break;
+
+               /* Assign vendor for vendor-specific decodes later */
+               if (h.type == 1 && h.length >= 6)
+               {
+                       dmi_set_vendor(_dmi_string(&h, data[0x04], 0),
+                                      _dmi_string(&h, data[0x05], 0));
+                       break;
+               }
+
+               data = next;
+       }
+
+       /* Second pass: Actually decode the data */
+       i = 0;
        data = buf;
        while ((i < num || !num)
            && data + 4 <= buf + len) /* 4 is the length of an SMBIOS structure 
header */
@@ -5241,11 +5286,6 @@ static void dmi_table_decode(u8 *buf, u3
                        break;
                }
 
-               /* assign vendor for vendor-specific decodes later */
-               if (h.type == 1 && h.length >= 6)
-                       dmi_set_vendor(_dmi_string(&h, data[0x04], 0),
-                                      _dmi_string(&h, data[0x05], 0));
-
                /* Fixup a common mistake */
                if (h.type == 34)
                        dmi_fixup_type_34(&h, display);


-- 
Jean Delvare
SUSE L3 Support