From cf4ae7c3bff2e22f3fb1a92a4cbaefb40a482251 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 10 Aug 2026 06:38:29 -0700 Subject: [PATCH] Harden PL/Perl code against "tied" Perl arrays and hashes. Tied arrays might report different sizes each time they are inspected. To avoid generating a corrupt result array, fix plperl_array_to_datum() to read av_len() of each input array only once. If the input does appear to get shorter, we'll fill nulls for the now-missing entries, which seems fine. Conversely, if it gets longer, we'll ignore the new entries. plperl_to_hstore() assumed that Perl's hv_iterinit() returns the number of entries in the given Perl hash. Usually that's true, but per the Perl docs, "the return value is currently only meaningful for hashes without tie magic". That could potentially end in a memory stomp. We don't depend on that result value anywhere else, so don't do so here either. Reported-by: Hcamael Author: Tom Lane Reviewed-by: Andrew Dunstan Backpatch-through: 14 Security: CVE-2026-14670 --- contrib/hstore_plperl/hstore_plperl.c | 11 +++++++++-- src/pl/plperl/plperl.c | 6 +++++- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/contrib/hstore_plperl/hstore_plperl.c b/contrib/hstore_plperl/hstore_plperl.c index 919a670e388..2a0c5000808 100644 --- a/contrib/hstore_plperl/hstore_plperl.c +++ b/contrib/hstore_plperl/hstore_plperl.c @@ -128,8 +128,9 @@ plperl_to_hstore(PG_FUNCTION_ARGS) errmsg("cannot transform non-hash Perl value to hstore"))); hv = (HV *) in; - pcount = hv_iterinit(hv); + (void) hv_iterinit(hv); + pcount = 64; /* arbitrary initial guess */ pairs = palloc_array(Pairs, pcount); i = 0; @@ -138,6 +139,12 @@ plperl_to_hstore(PG_FUNCTION_ARGS) char *key = sv2cstr(HeSVKEY_force(he)); SV *value = HeVAL(he); + if (i >= pcount) + { + pcount *= 2; + pairs = repalloc_array(pairs, Pairs, pcount); + } + pairs[i].key = pstrdup(key); pairs[i].keylen = hstoreCheckKeyLen(strlen(pairs[i].key)); pairs[i].needfree = true; @@ -158,7 +165,7 @@ plperl_to_hstore(PG_FUNCTION_ARGS) i++; } - pcount = hstoreUniquePairs(pairs, pcount, &buflen); + pcount = hstoreUniquePairs(pairs, i, &buflen); out = hstorePairs(pairs, pcount, buflen); PG_RETURN_POINTER(out); } diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c index 26ba25e46ce..cfd006ea1d0 100644 --- a/src/pl/plperl/plperl.c +++ b/src/pl/plperl/plperl.c @@ -1168,6 +1168,10 @@ get_perl_array_ref(SV *sv) * if we didn't do it like that, we'd need some other convention for knowing * whether we'd already found any scalars (and thus the number of dimensions * is frozen). + * + * Caller is required to have set dims[cur_depth - 1] to the length of the + * input array, i.e., av_len(av) + 1. We make this requirement so as to + * avoid reading av_len() twice, which is hazardous for tied arrays. */ static void array_to_datum_internal(AV *av, ArrayBuildState **astatep, @@ -1177,7 +1181,7 @@ array_to_datum_internal(AV *av, ArrayBuildState **astatep, { dTHX; int i; - int len = av_len(av) + 1; + int len = dims[cur_depth - 1]; for (i = 0; i < len; i++) {