Commit 09b326fa2b3198e462fc75f98973981f23ec7382
2023-03-01T12:19:17
Avoid strtol on non-null-terminated data. Technically, `strtol` can only be used with C strings terminated with `\0`. CID data is not generally null-terminated and often does not contain a `\0` if it is hex-encoded. AddressSanitizer with `ASAN_OPTIONS` containing `strict_string_checks=1` verifies this by using an adversarial `strtol` that always reads to the terminating `\0`. To avoid undefined behavior from `strtol` in `cid_parser_new`, use the parser to parse the tokens instead of attempting to parse them ad-hoc. This will internally use `PS_Conv_Strtol` to parse the integer, which respects the parser's limits and directly implements the PostScript parsing rules for integers. * src/cid/cidparse.c (cid_parser_new): Use the parser to parse the tokens. Fixes: https://bugs.chromium.org/p/chromium/issues/detail?id=1420329
diff --git a/src/cid/cidparse.c b/src/cid/cidparse.c
index 16889db..171a886 100644
--- a/src/cid/cidparse.c
+++ b/src/cid/cidparse.c
@@ -214,18 +214,24 @@
cur <= limit - STARTDATA_LEN &&
ft_strncmp( (char*)cur, STARTDATA, STARTDATA_LEN ) == 0 )
{
- if ( ft_strncmp( (char*)arg1, "(Hex)", 5 ) == 0 )
- {
- FT_Long tmp = ft_strtol( (const char *)arg2, NULL, 10 );
+ T1_TokenRec type_token;
+ FT_Long binary_length;
- if ( tmp < 0 )
+ parser->root.cursor = arg1;
+ cid_parser_to_token( parser, &type_token );
+ if ( type_token.limit - type_token.start == 5 &&
+ ft_memcmp( (char*)type_token.start, "(Hex)", 5 ) == 0 )
+ {
+ parser->root.cursor = arg2;
+ binary_length = cid_parser_to_int( parser );
+ if ( binary_length < 0 )
{
FT_ERROR(( "cid_parser_new: invalid length of hex data\n" ));
error = FT_THROW( Invalid_File_Format );
}
else
- parser->binary_length = (FT_ULong)tmp;
+ parser->binary_length = (FT_ULong)binary_length;
}
goto Exit;