At Tue, 15 Feb 2022 09:17:34 -0300, Ranier Vilela <ranier...@gmail.com> wrote in > Per Coverity.
Thanks for the source:) > Like the function pg_encoding_max_length_sql > (src/backend/utils/mb/mbutils.c) > Only assertion is insufficient to avoid accessing array out-of-bounds. > > This bug is live according Coverity at function: pg_verify_mbstr_len > (src/backend/utils/mb/mbutils.c) > CID 1469870 (#1 of 1): Out-of-bounds access (OVERRUN)7. overrun-call: > Overrunning > callee's array of size 42 by passing argument src_encoding (which evaluates > to 63) in call to pg_verify_mbstr_len. [show details > <https://scan6.scan.coverity.com/eventId=32693869-7&modelId=32693869-0&fileInstanceId=131415642&filePath=%2Fdll%2Fpostgres%2Fpostgres%2Fsrc%2Fbackend%2Futils%2Fmb%2Fmbutils.c&fileStart=1546&fileEnd=1605> It returns 400.. > ] > 633 retval = pg_verify_mbstr_len(src_encoding, src_str, len, false); > 634 > > Trivial patch attached. Mmm? If the assert doesn't work, there should be inconcsistency between pg_enc and pg_wchar_table. But AFAICS they are consistent. The patch: pg_encoding_max_length(int encoding) { - Assert(PG_VALID_ENCODING(encoding)); - - return pg_wchar_table[encoding].maxmblen; + if (PG_VALID_ENCODING(encoding)) + return pg_wchar_table[encoding].maxmblen; + else + return -1; Returning -1 for invalid encoding is, I think, flat wrong. > 633 retval = pg_verify_mbstr_len(src_encoding, src_str, len, false); The src_encoding comes from pg_char_to_encoding. It returns pg_encname_tbl[n]->encoding, which seems to reutrn a value of pg_enc. the max value of which is 42. So I don't come up with a hypothesis that makes it possible for now.. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
