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| author | Michael Paquier <michael@paquier.xyz> | 2023-04-18 11:20:47 +0900 |
|---|---|---|
| committer | Michael Paquier <michael@paquier.xyz> | 2023-04-18 11:20:47 +0900 |
| commit | 8c746be44002e8f95dcf8e98f58a47ac851563ee (patch) | |
| tree | df033fa375860353f7896bde0b8a79fec2560f26 /src/interfaces/ecpg/ecpglib/data.c | |
| parent | 2207df7c34bfcecec33da2a47068e94d7882ffdb (diff) | |
| download | postgresql-8c746be44002e8f95dcf8e98f58a47ac851563ee.tar.gz postgresql-8c746be44002e8f95dcf8e98f58a47ac851563ee.zip | |
ecpg: Fix handling of strings in ORACLE compat code with SQLDA
When compiled with -C ORACLE, ecpg_get_data() had a one-off issue where
it would incorrectly store the null terminator byte to str[-1] when
varcharsize is 0, which is something that can happen when using SQLDA.
This would eat 1 byte from the previous field stored, corrupting the
results generated.
All the callers of ecpg_get_data() estimate and allocate enough storage
for the data received, and the fix of this commit relies on this
assumption. Note that this maps to the case where no padding or
truncation is required.
This issue has been introduced by 3b7ab43 with the Oracle compatibility
option, so backpatch down to v11.
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20230410.173500.440060475837236886.horikyota.ntt@gmail.com
Backpatch-through: 11
Diffstat (limited to 'src/interfaces/ecpg/ecpglib/data.c')
| -rw-r--r-- | src/interfaces/ecpg/ecpglib/data.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/src/interfaces/ecpg/ecpglib/data.c b/src/interfaces/ecpg/ecpglib/data.c index a1bba42bb8f..40cbfc0d078 100644 --- a/src/interfaces/ecpg/ecpglib/data.c +++ b/src/interfaces/ecpg/ecpglib/data.c @@ -581,7 +581,7 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno, if (varcharsize == 0 && offset == sizeof(char *)) str = *(char **) str; - if (varcharsize == 0 || varcharsize > size) + if (varcharsize > size) { /* * compatibility mode, blank pad and null @@ -641,16 +641,25 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno, } else { - strncpy(str, pval, varcharsize); + int charsize = varcharsize; + + /* + * assume that the caller provided storage exactly + * fit when varcharsize is zero. + */ + if (varcharsize == 0) + charsize = size + 1; + + strncpy(str, pval, charsize); /* compatibility mode, null terminate char array */ - if (ORACLE_MODE(compat) && (varcharsize - 1) < size) + if (ORACLE_MODE(compat) && (charsize - 1) < size) { if (type == ECPGt_char || type == ECPGt_unsigned_char) - str[varcharsize - 1] = '\0'; + str[charsize - 1] = '\0'; } - if (varcharsize < size || (ORACLE_MODE(compat) && (varcharsize - 1) < size)) + if (charsize < size || (ORACLE_MODE(compat) && (charsize - 1) < size)) { /* truncation */ switch (ind_type) |