File 1110-dec_term-avoid-integer-overflow-for-LIST_E... of Package erlang

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File 1110-dec_term-avoid-integer-overflow-for-LIST_EXT.patch of Package erlang (Revision c45f22bce6f654206ec2729d74bc90ca)

Currently displaying revision c45f22bce6f654206ec2729d74bc90ca , Show latest

From 2ac0aede4cf48c0eea401562b2e94e4baf45dfe2 Mon Sep 17 00:00:00 2001
From: Mikael Pettersson <mikpelinux@gmail.com>
Date: Sun, 6 Nov 2022 17:56:53 +0100
Subject: [PATCH] dec_term: avoid integer overflow for LIST_EXT

- use unsigned type for the length n
- perform mutiplication by 2 in wider type

Fixes #6439
---
 erts/emulator/beam/external.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 63d7d32487..b2ce5c68eb 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -4182,37 +4182,39 @@ dec_term_atom_common:
 	    *objp = NIL;
 	    break;
 	case LIST_EXT:
-	    n = get_int32(ep);
+	{
+	    Uint32 nu = get_uint32(ep);
 	    ep += 4;
-	    if (n == 0) {
+	    if (nu == 0) {
 		next = objp;
 		break;
 	    }
 	    *objp = make_list(hp);
-            hp += 2 * n;
+            hp += 2 * (Uint) nu;
 	    objp = hp - 2;
 	    objp[0] = (Eterm) (objp+1);
 	    objp[1] = (Eterm) next;
 	    next = objp;
 	    objp -= 2;
-            n--;
+            nu--;
 	    if (ctx) {
-                if (reds < n) {
+                if ((Uint) reds < nu) {
                     ASSERT(reds > 0);
 		    ctx->state = B2TDecodeList;
-		    ctx->u.dc.remaining_n = n - reds;
-		    n = reds;
+		    ctx->u.dc.remaining_n = nu - reds;
+		    nu = reds;
 		}
-		reds -= n;
+		reds -= nu;
 	    }
-            while (n > 0) {
+            while (nu > 0) {
 		objp[0] = (Eterm) next;
 		objp[1] = make_list(next);
 		next = objp;
 		objp -= 2;
-                n--;
+                nu--;
 	    }
 	    break;
+	}
 	case STRING_EXT:
 	    n = get_int16(ep);
 	    ep += 2;
-- 
2.35.3

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File 1110-dec_term-avoid-integer-overflow-for-LIST_EXT.patch of Package erlang (Revision c45f22bce6f654206ec2729d74bc90ca)

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