From efccedf261ab519b2b5ebe9767d0d78a35be7727 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 8 Apr 2026 17:09:16 -0400 Subject: [PATCH v1] Guard against overly-long numeric formatting symbols from locale. to_char() allocates its output buffer with 8 bytes per formatting code in the pattern. If the locale's currency symbol, thousands separator, or decimal or sign symbol is more than 8 bytes long, in principle we could overrun the output buffer. No such locales exist in the real world, so it seems sufficient to truncate the symbol if we do see it's too long. Reported-by: Xint Code Author: Tom Lane Backpatch-through: 14 --- src/backend/utils/adt/formatting.c | 61 +++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 18 deletions(-) diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c index 0716aff22b6..9a8c99336b5 100644 --- a/src/backend/utils/adt/formatting.c +++ b/src/backend/utils/adt/formatting.c @@ -1114,6 +1114,7 @@ static void NUM_prepare_locale(NUMProc *Np); static const char *get_last_relevant_decnum(const char *num); static void NUM_numpart_from_char(NUMProc *Np, int id, size_t input_len); static void NUM_numpart_to_char(NUMProc *Np, int id); +static void NUM_add_locale_symbol(NUMProc *Np, const char *pattern); static char *NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number, size_t input_len, int to_char_out_pre_spaces, int sign, bool is_to_char, Oid collid); @@ -5568,11 +5569,9 @@ NUM_numpart_to_char(NUMProc *Np, int id) { if (Np->Num->lsign == NUM_LSIGN_PRE) { - if (Np->sign == '-') - strcpy(Np->inout_p, Np->L_negative_sign); - else - strcpy(Np->inout_p, Np->L_positive_sign); - Np->inout_p += strlen(Np->inout_p); + NUM_add_locale_symbol(Np, (Np->sign == '-') ? + Np->L_negative_sign : + Np->L_positive_sign); Np->sign_wrote = true; } } @@ -5637,8 +5636,7 @@ NUM_numpart_to_char(NUMProc *Np, int id) { if (!Np->last_relevant || *Np->last_relevant != '.') { - strcpy(Np->inout_p, Np->decimal); /* Write DEC/D */ - Np->inout_p += strlen(Np->inout_p); + NUM_add_locale_symbol(Np, Np->decimal); /* Write DEC/D */ } /* @@ -5647,8 +5645,7 @@ NUM_numpart_to_char(NUMProc *Np, int id) else if (IS_FILLMODE(Np->Num) && Np->last_relevant && *Np->last_relevant == '.') { - strcpy(Np->inout_p, Np->decimal); /* Write DEC/D */ - Np->inout_p += strlen(Np->inout_p); + NUM_add_locale_symbol(Np, Np->decimal); /* Write DEC/D */ } } else @@ -5706,11 +5703,9 @@ NUM_numpart_to_char(NUMProc *Np, int id) } else if (IS_LSIGN(Np->Num) && Np->Num->lsign == NUM_LSIGN_POST) { - if (Np->sign == '-') - strcpy(Np->inout_p, Np->L_negative_sign); - else - strcpy(Np->inout_p, Np->L_positive_sign); - Np->inout_p += strlen(Np->inout_p); + NUM_add_locale_symbol(Np, (Np->sign == '-') ? + Np->L_negative_sign : + Np->L_positive_sign); } } } @@ -5718,6 +5713,23 @@ NUM_numpart_to_char(NUMProc *Np, int id) ++Np->num_curr; } +/* + * Append locale-specific symbol to Np->inout. + * Note we don't null-terminate the output + */ +static void +NUM_add_locale_symbol(NUMProc *Np, const char *pattern) +{ + size_t pattern_len = strlen(pattern); + + /* Truncate symbol if it's potentially too long */ + if (unlikely(pattern_len > NUM_MAX_ITEM_SIZ)) + pattern_len = pg_mbcliplen(pattern, pattern_len, + NUM_MAX_ITEM_SIZ); + memcpy(Np->inout_p, pattern, pattern_len); + Np->inout_p += pattern_len; +} + /* * Skip over "n" input characters, but only if they aren't numeric data */ @@ -5965,6 +5977,10 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, pattern_len = strlen(pattern); if (Np->is_to_char) { + /* Truncate symbol if it's potentially too long */ + if (unlikely(pattern_len > NUM_MAX_ITEM_SIZ)) + pattern_len = pg_mbcliplen(pattern, pattern_len, + NUM_MAX_ITEM_SIZ); if (!Np->num_in) { if (IS_FILLMODE(Np->Num)) @@ -5972,19 +5988,21 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, else { /* just in case there are MB chars */ - pattern_len = pg_mbstrlen(pattern); + pattern_len = pg_mbstrlen_with_len(pattern, + pattern_len); memset(Np->inout_p, ' ', pattern_len); Np->inout_p += pattern_len - 1; } } else { - strcpy(Np->inout_p, pattern); + memcpy(Np->inout_p, pattern, pattern_len); Np->inout_p += pattern_len - 1; } } else { + /* Here we do not truncate the symbol ... */ if (!Np->num_in) { if (IS_FILLMODE(Np->Num)) @@ -6009,11 +6027,18 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, pattern = Np->L_currency_symbol; if (Np->is_to_char) { - strcpy(Np->inout_p, pattern); - Np->inout_p += strlen(pattern) - 1; + /* Truncate symbol if it's potentially too long */ + pattern_len = strlen(pattern); + if (unlikely(pattern_len > NUM_MAX_ITEM_SIZ)) + pattern_len = pg_mbcliplen(pattern, pattern_len, + NUM_MAX_ITEM_SIZ); + + memcpy(Np->inout_p, pattern, pattern_len); + Np->inout_p += pattern_len - 1; } else { + /* Here we do not truncate the symbol ... */ NUM_eat_non_data_chars(Np, pg_mbstrlen(pattern), input_len); continue; } -- 2.43.7