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Back-patch pg_encoding_verifymbstr()/pg_encoding_verifymbchar() to v13.

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A security fix will need those functions, so back-patch the v14+ functions to
v13.

When commit b80e10638e36b9d2f0b39170c613837af2ca2aac introduced the v14+
implementation of pg_encoding_verifymbstr(), it added a callback to each
pg_wchar_table entry.  For simplicity and ABI stability, this instead
implements the function in terms of the existing per-character callback.

Author: Noah Misch <noah@leadboat.com>
Author: Andres Freund <andres@anarazel.de>
Security: CVE-2025-1094
This commit is contained in:
Andres Freund 2025-02-10 10:03:40 -05:00
parent bf085f6d45
commit 00f1a1f665
2 changed files with 68 additions and 0 deletions
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66
src/common/wchar.c
View File

@ -1597,6 +1597,72 @@ pg_encoding_verifymb(int encoding, const char *mbstr, int len)
pg_wchar_table[PG_SQL_ASCII].mbverify((const unsigned char *) mbstr, len));
}
/* v14+ function name, for easier backpatching */
int
pg_encoding_verifymbchar(int encoding, const char *mbstr, int len)
{
int ok_bytes = pg_encoding_verifymb(encoding, mbstr, len);
if (ok_bytes == 0)
return -1;
return ok_bytes;
}
/* replace v14+ function, adapted from pg_verify_mbstr_len */
int
pg_encoding_verifymbstr(int encoding, const char *mbstr, int len)
{
mbverifier mbverify;
int ok_bytes;
Assert(PG_VALID_ENCODING(encoding));
/*
* In single-byte encodings, we need only reject nulls (\0).
*/
if (pg_encoding_max_length(encoding) <= 1)
{
const char *nullpos = memchr(mbstr, 0, len);
if (nullpos == NULL)
return len;
return nullpos - mbstr;
}
/* fetch function pointer just once */
mbverify = pg_wchar_table[encoding].mbverify;
ok_bytes = 0;
while (len > 0)
{
int l;
/* fast path for ASCII-subset characters */
if (!IS_HIGHBIT_SET(*mbstr))
{
if (*mbstr != '\0')
{
ok_bytes++;
mbstr++;
len--;
continue;
}
return ok_bytes;
}
l = (*mbverify) ((const unsigned char *) mbstr, len);
if (l < 0)
return ok_bytes;
mbstr += l;
len -= l;
ok_bytes += l;
}
return ok_bytes;
}
/*
* fetch maximum length of a given encoding
*/

2
src/include/mb/pg_wchar.h
View File

@ -556,6 +556,8 @@ extern int pg_encoding_mblen(int encoding, const char *mbstr);
extern int pg_encoding_mblen_bounded(int encoding, const char *mbstr);
extern int pg_encoding_dsplen(int encoding, const char *mbstr);
extern int pg_encoding_verifymb(int encoding, const char *mbstr, int len);
extern int pg_encoding_verifymbchar(int encoding, const char *mbstr, int len);
extern int pg_encoding_verifymbstr(int encoding, const char *mbstr, int len);
extern int pg_encoding_max_length(int encoding);
extern int pg_valid_client_encoding(const char *name);
extern int pg_valid_server_encoding(const char *name);