If the initial part of the header (‘MIME-TreeMagic’) is valid, but the
following line does not start with ‘[’ (i.e. is not a valid section
line), insert_matchlet() will be called with a NULL match pointer, and
will crash with a NULL pointer dereference.
Fix this by bailing out if a valid section line isn’t encountered before
the first insert_matchlet() call (i.e. between the header line and the
first data line).
Note that this has not been tested against a real treemagic file; the
fix is purely theoretical.
Found by scan-build.
https://bugzilla.gnome.org/show_bug.cgi?id=113075
match = parse_header (lines[i]);
insert_match (match);
}
- else
+ else if (match != NULL)
{
matchlet = parse_match_line (lines[i], &depth);
insert_matchlet (match, matchlet, depth);
}
+ else
+ {
+ g_warning ("%s: header corrupt; skipping\n", filename);
+ break;
+ }
}
g_strfreev (lines);