diff -Naur libarchive-3.7.7/libarchive/archive_read_support_format_tar.c libarchive-3.7.7-patch/libarchive/archive_read_support_format_tar.c
--- libarchive-3.7.7/libarchive/archive_read_support_format_tar.c	2026-08-18 08:43:36.246102967 +0200
+++ libarchive-3.7.7-patch/libarchive/archive_read_support_format_tar.c	2026-08-18 08:49:13.860883568 +0200
@@ -42,6 +42,7 @@
 #include "archive_acl_private.h" /* For ACL parsing routines. */
 #include "archive_entry.h"
 #include "archive_entry_locale.h"
+#include "archive_integer.h"
 #include "archive_private.h"
 #include "archive_read_private.h"
 
@@ -3246,13 +3247,10 @@
 				return (ARCHIVE_FATAL);
 			tar->sparse_last->hole = hole;
 		}
-		if (length == 0 || *e == '\n') {
-			if (length == 0 && *e == '\n') {
-				return (ARCHIVE_OK);
-			} else {
-				return (ARCHIVE_WARN);
-			}
-		}
+        if (length == 0)
+			return (ARCHIVE_OK);
+		if (*e == '\n')
+			return (ARCHIVE_WARN);
 		p = e + 1;
 		length--;
 		hole = hole == 0;
@@ -3296,13 +3294,9 @@
 static int64_t
 tar_atol_base_n(const char *p, size_t char_cnt, int base)
 {
-	int64_t	l, maxval, limit, last_digit_limit;
+	int64_t	l;
 	int digit, sign;
 
-	maxval = INT64_MAX;
-	limit = INT64_MAX / base;
-	last_digit_limit = INT64_MAX % base;
-
 	/* the pointer will not be dereferenced if char_cnt is zero
 	 * due to the way the && operator is evaluated.
 	 */
@@ -3316,25 +3310,22 @@
 		sign = -1;
 		p++;
 		char_cnt--;
-
-		maxval = INT64_MIN;
-		limit = -(INT64_MIN / base);
-		last_digit_limit = -(INT64_MIN % base);
 	}
 
 	l = 0;
-	if (char_cnt != 0) {
+	while (char_cnt != 0) {
 		digit = *p - '0';
-		while (digit >= 0 && digit < base  && char_cnt != 0) {
-			if (l>limit || (l == limit && digit >= last_digit_limit)) {
-				return maxval; /* Truncate on overflow. */
-			}
-			l = (l * base) + digit;
-			digit = *++p - '0';
-			char_cnt--;
+		if (digit < 0 || digit >= base)
+			break;
+		if (archive_ckd_mul_i64(&l, l, base) ||
+		    archive_ckd_add_i64(&l, l, sign * digit)) {
+			 /* Truncate on overflow. */
+			return sign < 0 ? INT64_MIN : INT64_MAX;        
 		}
+        p++;
+        char_cnt--;
 	}
-	return (sign < 0) ? -l : l;
+	return l;
 }
 
 static int64_t