rel 2; CVE thing probably

[packages/libspf2.git] / integer-underflow.patch

From c93823faef044150e1b232928d225ff5ff297e6c Mon Sep 17 00:00:00 2001
From: Simon Arlott <sa.me.uk>
Date: Sat, 30 Sep 2023 12:18:51 +0100
Subject: [PATCH] Fix integer underflow

---
 src/libspf2/spf_compile.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libspf2/spf_compile.c b/src/libspf2/spf_compile.c
index b08ffe2..d401028 100644
--- a/src/libspf2/spf_compile.c
+++ b/src/libspf2/spf_compile.c
@@ -455,7 +455,11 @@ SPF_c_parse_var(SPF_response_t *spf_response, SPF_data_var_t *data,
 			/* Magic numbers for x/Nc in gdb. */					\
 			data->ds.__unused0 = 0xba; data->ds.__unused1 = 0xbe;	\
 			dst = SPF_data_str( data );								\
-			ds_avail = _avail - sizeof(SPF_data_t);					\
+			if ((_avail) < sizeof(SPF_data_t))						\
+				return SPF_response_add_error_ptr(spf_response,		\
+									SPF_E_BIG_STRING, NULL, src,	\
+								"Out of memory for string literal");\
+			ds_avail = (_avail) - sizeof(SPF_data_t);				\
 			ds_len = 0;												\
 		} while(0)