From 23b489104fc35d2341d97845894668ef14dd1bb0 Mon Sep 17 00:00:00 2001
From: Yue Chang <angelachang27@gmail.com>
Date: Fri, 12 Jun 2026 01:41:44 -0400
Subject: [PATCH] Fix integer overflow in LAPACKE nancheck helpers for large
 matrices

Offset computations like j*lda overflow 32-bit lapack_int once
n = lda >= 46341, e.g. LAPACKE_dpotrf crashes in its NaN check before
the factorization runs. Cast to size_t (or int64_t for the tz offsets)
the same way ge/gb/tp/tf already do.
---
 LAPACKE/utils/lapacke_c_nancheck.c   |  4 ++--
 LAPACKE/utils/lapacke_chp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_cpf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_cpp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_csp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ctf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ctp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ctr_nancheck.c |  4 ++--
 LAPACKE/utils/lapacke_ctz_nancheck.c | 12 ++++++------
 LAPACKE/utils/lapacke_d_nancheck.c   |  4 ++--
 LAPACKE/utils/lapacke_dpf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_dpp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_dsp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_dtf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_dtp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_dtr_nancheck.c |  4 ++--
 LAPACKE/utils/lapacke_dtz_nancheck.c | 12 ++++++------
 LAPACKE/utils/lapacke_s_nancheck.c   |  4 ++--
 LAPACKE/utils/lapacke_spf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_spp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ssp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_stf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_stp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_str_nancheck.c |  4 ++--
 LAPACKE/utils/lapacke_stz_nancheck.c | 12 ++++++------
 LAPACKE/utils/lapacke_z_nancheck.c   |  4 ++--
 LAPACKE/utils/lapacke_zhp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_zpf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_zpp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_zsp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ztf_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ztp_nancheck.c |  2 +-
 LAPACKE/utils/lapacke_ztr_nancheck.c |  4 ++--
 LAPACKE/utils/lapacke_ztz_nancheck.c | 12 ++++++------
 34 files changed, 62 insertions(+), 62 deletions(-)

diff --git a/LAPACKE/utils/lapacke_c_nancheck.c b/LAPACKE/utils/lapacke_c_nancheck.c
index d635fd5bfe..be157ae73c 100644
--- a/LAPACKE/utils/lapacke_c_nancheck.c
+++ b/LAPACKE/utils/lapacke_c_nancheck.c
@@ -42,8 +42,8 @@ lapack_logical API_SUFFIX(LAPACKE_c_nancheck)( lapack_int n,
     if( incx == 0 ) return (lapack_logical) LAPACK_CISNAN( x[0] );
     inc = ( incx > 0 ) ? incx : -incx ;
 
-    for( i = 0; i < n*inc; i+=inc ) {
-        if( LAPACK_CISNAN( x[i] ) )
+    for( i = 0; i < n; i++ ) {
+        if( LAPACK_CISNAN( x[(size_t)i*inc] ) )
             return (lapack_logical) 1;
     }
     return (lapack_logical) 0;
diff --git a/LAPACKE/utils/lapacke_chp_nancheck.c b/LAPACKE/utils/lapacke_chp_nancheck.c
index ba24f2a1b4..5c06a809a3 100644
--- a/LAPACKE/utils/lapacke_chp_nancheck.c
+++ b/LAPACKE/utils/lapacke_chp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_chp_nancheck)( lapack_int n,
                                       const lapack_complex_float *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_c_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_cpf_nancheck.c b/LAPACKE/utils/lapacke_cpf_nancheck.c
index ae9eb67e75..bd29b7a748 100644
--- a/LAPACKE/utils/lapacke_cpf_nancheck.c
+++ b/LAPACKE/utils/lapacke_cpf_nancheck.c
@@ -40,6 +40,6 @@
 lapack_logical API_SUFFIX(LAPACKE_cpf_nancheck)( lapack_int n,
                                       const lapack_complex_float *a )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_c_nancheck)( len, a, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_cpp_nancheck.c b/LAPACKE/utils/lapacke_cpp_nancheck.c
index 287b8f67f3..e4e014d5bb 100644
--- a/LAPACKE/utils/lapacke_cpp_nancheck.c
+++ b/LAPACKE/utils/lapacke_cpp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_cpp_nancheck)( lapack_int n,
                                       const lapack_complex_float *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_c_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_csp_nancheck.c b/LAPACKE/utils/lapacke_csp_nancheck.c
index d6f840729c..cfbbf11bec 100644
--- a/LAPACKE/utils/lapacke_csp_nancheck.c
+++ b/LAPACKE/utils/lapacke_csp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_csp_nancheck)( lapack_int n,
                                       const lapack_complex_float *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_c_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_ctf_nancheck.c b/LAPACKE/utils/lapacke_ctf_nancheck.c
index 193e96f546..bbe54f5a3d 100644
--- a/LAPACKE/utils/lapacke_ctf_nancheck.c
+++ b/LAPACKE/utils/lapacke_ctf_nancheck.c
@@ -150,7 +150,7 @@ lapack_logical API_SUFFIX(LAPACKE_ctf_nancheck)( int matrix_layout, char transr,
         }
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_cge_nancheck)( LAPACK_COL_MAJOR, len, 1, a, len );
     }
 }
diff --git a/LAPACKE/utils/lapacke_ctp_nancheck.c b/LAPACKE/utils/lapacke_ctp_nancheck.c
index eb245ff511..afcafc2f75 100644
--- a/LAPACKE/utils/lapacke_ctp_nancheck.c
+++ b/LAPACKE/utils/lapacke_ctp_nancheck.c
@@ -76,7 +76,7 @@ lapack_logical API_SUFFIX(LAPACKE_ctp_nancheck)( int matrix_layout, char uplo, c
         return (lapack_logical) 0;
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_c_nancheck)( len, ap, 1 );
     }
 }
diff --git a/LAPACKE/utils/lapacke_ctr_nancheck.c b/LAPACKE/utils/lapacke_ctr_nancheck.c
index c21adfdce7..b0f9e7df2c 100644
--- a/LAPACKE/utils/lapacke_ctr_nancheck.c
+++ b/LAPACKE/utils/lapacke_ctr_nancheck.c
@@ -68,14 +68,14 @@ lapack_logical API_SUFFIX(LAPACKE_ctr_nancheck)( int matrix_layout, char uplo, c
     if( ( colmaj || lower ) && !( colmaj && lower ) ) {
         for( j = st; j < n; j++ ) {
             for( i = 0; i < MIN( j+1-st, lda ); i++ ) {
-                if( LAPACK_CISNAN( a[i+j*lda] ) )
+                if( LAPACK_CISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
     } else {
         for( j = 0; j < n-st; j++ ) {
             for( i = j+st; i < MIN( n, lda ); i++ ) {
-                if( LAPACK_CISNAN( a[i+j*lda] ) )
+                if( LAPACK_CISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
diff --git a/LAPACKE/utils/lapacke_ctz_nancheck.c b/LAPACKE/utils/lapacke_ctz_nancheck.c
index 91f759b46c..dc466c3f2b 100644
--- a/LAPACKE/utils/lapacke_ctz_nancheck.c
+++ b/LAPACKE/utils/lapacke_ctz_nancheck.c
@@ -103,27 +103,27 @@ lapack_logical API_SUFFIX(LAPACKE_ctz_nancheck)( int matrix_layout, char direct,
     }
 
     /* Initial offsets and sizes of triangular and rectangular parts */
-    lapack_int tri_offset = 0;
+    int64_t tri_offset = 0;
     lapack_int tri_n = MIN(m,n);
-    lapack_int rect_offset = -1;
+    int64_t rect_offset = -1;
     lapack_int rect_m = ( m > n ) ? m - n : m;
     lapack_int rect_n = ( n > m ) ? n - m : n;
 
     /* Fix offsets depending on the shape of the matrix */
     if( front ) {
         if( lower && m > n ) {
-            rect_offset = tri_n * ( !colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( !colmaj ? lda : 1 );
         } else if( !lower && n > m ) {
-            rect_offset = tri_n * ( colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( colmaj ? lda : 1 );
         }
     } else {
         if( m > n ) {
-            tri_offset = rect_m * ( !colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_m * ( !colmaj ? lda : 1 );
             if( !lower ) {
                 rect_offset = 0;
             }
         } else if( n > m ) {
-            tri_offset = rect_n * ( colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_n * ( colmaj ? lda : 1 );
             if( lower ) {
                 rect_offset = 0;
             }
diff --git a/LAPACKE/utils/lapacke_d_nancheck.c b/LAPACKE/utils/lapacke_d_nancheck.c
index 0ae9ea220e..a3dcf081c5 100644
--- a/LAPACKE/utils/lapacke_d_nancheck.c
+++ b/LAPACKE/utils/lapacke_d_nancheck.c
@@ -42,8 +42,8 @@ lapack_logical API_SUFFIX(LAPACKE_d_nancheck)( lapack_int n,
     if( incx == 0 ) return (lapack_logical) LAPACK_DISNAN( x[0] );
     inc = ( incx > 0 ) ? incx : -incx ;
 
-    for( i = 0; i < n*inc; i+=inc ) {
-        if( LAPACK_DISNAN( x[i] ) )
+    for( i = 0; i < n; i++ ) {
+        if( LAPACK_DISNAN( x[(size_t)i*inc] ) )
             return (lapack_logical) 1;
     }
     return (lapack_logical) 0;
diff --git a/LAPACKE/utils/lapacke_dpf_nancheck.c b/LAPACKE/utils/lapacke_dpf_nancheck.c
index 62561b85b5..c186121429 100644
--- a/LAPACKE/utils/lapacke_dpf_nancheck.c
+++ b/LAPACKE/utils/lapacke_dpf_nancheck.c
@@ -40,6 +40,6 @@
 lapack_logical API_SUFFIX(LAPACKE_dpf_nancheck)( lapack_int n,
                                       const double *a )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_d_nancheck)( len, a, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_dpp_nancheck.c b/LAPACKE/utils/lapacke_dpp_nancheck.c
index a94473a40e..cf0141540c 100644
--- a/LAPACKE/utils/lapacke_dpp_nancheck.c
+++ b/LAPACKE/utils/lapacke_dpp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_dpp_nancheck)( lapack_int n,
                                       const double *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_d_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_dsp_nancheck.c b/LAPACKE/utils/lapacke_dsp_nancheck.c
index 19b37b7aa6..965841d6be 100644
--- a/LAPACKE/utils/lapacke_dsp_nancheck.c
+++ b/LAPACKE/utils/lapacke_dsp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_dsp_nancheck)( lapack_int n,
                                       const double *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_d_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_dtf_nancheck.c b/LAPACKE/utils/lapacke_dtf_nancheck.c
index 23ebc7b357..0ac3f5b558 100644
--- a/LAPACKE/utils/lapacke_dtf_nancheck.c
+++ b/LAPACKE/utils/lapacke_dtf_nancheck.c
@@ -150,7 +150,7 @@ lapack_logical API_SUFFIX(LAPACKE_dtf_nancheck)( int matrix_layout, char transr,
         }
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_dge_nancheck)( LAPACK_COL_MAJOR, len, 1, a, len );
     }
 }
diff --git a/LAPACKE/utils/lapacke_dtp_nancheck.c b/LAPACKE/utils/lapacke_dtp_nancheck.c
index 804e6057fc..f39361b157 100644
--- a/LAPACKE/utils/lapacke_dtp_nancheck.c
+++ b/LAPACKE/utils/lapacke_dtp_nancheck.c
@@ -76,7 +76,7 @@ lapack_logical API_SUFFIX(LAPACKE_dtp_nancheck)( int matrix_layout, char uplo, c
         return (lapack_logical) 0;
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_d_nancheck)( len, ap, 1 );
     }
 }
diff --git a/LAPACKE/utils/lapacke_dtr_nancheck.c b/LAPACKE/utils/lapacke_dtr_nancheck.c
index 8696804bfe..72431030bc 100644
--- a/LAPACKE/utils/lapacke_dtr_nancheck.c
+++ b/LAPACKE/utils/lapacke_dtr_nancheck.c
@@ -68,14 +68,14 @@ lapack_logical API_SUFFIX(LAPACKE_dtr_nancheck)( int matrix_layout, char uplo, c
     if( ( colmaj || lower ) && !( colmaj && lower ) ) {
         for( j = st; j < n; j++ ) {
             for( i = 0; i < MIN( j+1-st, lda ); i++ ) {
-                if( LAPACK_DISNAN( a[i+j*lda] ) )
+                if( LAPACK_DISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
     } else {
         for( j = 0; j < n-st; j++ ) {
             for( i = j+st; i < MIN( n, lda ); i++ ) {
-                if( LAPACK_DISNAN( a[i+j*lda] ) )
+                if( LAPACK_DISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
diff --git a/LAPACKE/utils/lapacke_dtz_nancheck.c b/LAPACKE/utils/lapacke_dtz_nancheck.c
index b3e6c0f646..4956d6cb94 100644
--- a/LAPACKE/utils/lapacke_dtz_nancheck.c
+++ b/LAPACKE/utils/lapacke_dtz_nancheck.c
@@ -102,27 +102,27 @@ lapack_logical API_SUFFIX(LAPACKE_dtz_nancheck)( int matrix_layout, char direct,
     }
 
     /* Initial offsets and sizes of triangular and rectangular parts */
-    lapack_int tri_offset = 0;
+    int64_t tri_offset = 0;
     lapack_int tri_n = MIN(m,n);
-    lapack_int rect_offset = -1;
+    int64_t rect_offset = -1;
     lapack_int rect_m = ( m > n ) ? m - n : m;
     lapack_int rect_n = ( n > m ) ? n - m : n;
 
     /* Fix offsets depending on the shape of the matrix */
     if( front ) {
         if( lower && m > n ) {
-            rect_offset = tri_n * ( !colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( !colmaj ? lda : 1 );
         } else if( !lower && n > m ) {
-            rect_offset = tri_n * ( colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( colmaj ? lda : 1 );
         }
     } else {
         if( m > n ) {
-            tri_offset = rect_m * ( !colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_m * ( !colmaj ? lda : 1 );
             if( !lower ) {
                 rect_offset = 0;
             }
         } else if( n > m ) {
-            tri_offset = rect_n * ( colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_n * ( colmaj ? lda : 1 );
             if( lower ) {
                 rect_offset = 0;
             }
diff --git a/LAPACKE/utils/lapacke_s_nancheck.c b/LAPACKE/utils/lapacke_s_nancheck.c
index 8913630049..b71f259ea7 100644
--- a/LAPACKE/utils/lapacke_s_nancheck.c
+++ b/LAPACKE/utils/lapacke_s_nancheck.c
@@ -42,8 +42,8 @@ lapack_logical API_SUFFIX(LAPACKE_s_nancheck)( lapack_int n,
     if( incx == 0 ) return (lapack_logical) LAPACK_SISNAN( x[0] );
     inc = ( incx > 0 ) ? incx : -incx ;
 
-    for( i = 0; i < n*inc; i+=inc ) {
-        if( LAPACK_SISNAN( x[i] ) )
+    for( i = 0; i < n; i++ ) {
+        if( LAPACK_SISNAN( x[(size_t)i*inc] ) )
             return (lapack_logical) 1;
     }
     return (lapack_logical) 0;
diff --git a/LAPACKE/utils/lapacke_spf_nancheck.c b/LAPACKE/utils/lapacke_spf_nancheck.c
index 2787aa7f33..a06db4ff55 100644
--- a/LAPACKE/utils/lapacke_spf_nancheck.c
+++ b/LAPACKE/utils/lapacke_spf_nancheck.c
@@ -40,6 +40,6 @@
 lapack_logical API_SUFFIX(LAPACKE_spf_nancheck)( lapack_int n,
                                       const float *a )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_s_nancheck)( len, a, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_spp_nancheck.c b/LAPACKE/utils/lapacke_spp_nancheck.c
index f9fd816aed..81bb6f9223 100644
--- a/LAPACKE/utils/lapacke_spp_nancheck.c
+++ b/LAPACKE/utils/lapacke_spp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_spp_nancheck)( lapack_int n,
                                       const float *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_s_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_ssp_nancheck.c b/LAPACKE/utils/lapacke_ssp_nancheck.c
index 37bbc475e1..77a605aaf8 100644
--- a/LAPACKE/utils/lapacke_ssp_nancheck.c
+++ b/LAPACKE/utils/lapacke_ssp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_ssp_nancheck)( lapack_int n,
                                       const float *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_s_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_stf_nancheck.c b/LAPACKE/utils/lapacke_stf_nancheck.c
index a9d4d7e4d1..cefd21870a 100644
--- a/LAPACKE/utils/lapacke_stf_nancheck.c
+++ b/LAPACKE/utils/lapacke_stf_nancheck.c
@@ -151,7 +151,7 @@ lapack_logical API_SUFFIX(LAPACKE_stf_nancheck)( int matrix_layout, char transr,
         }
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_sge_nancheck)( LAPACK_COL_MAJOR, len, 1, a, len );
     }
 }
diff --git a/LAPACKE/utils/lapacke_stp_nancheck.c b/LAPACKE/utils/lapacke_stp_nancheck.c
index 105be69e18..523ffb4bf6 100644
--- a/LAPACKE/utils/lapacke_stp_nancheck.c
+++ b/LAPACKE/utils/lapacke_stp_nancheck.c
@@ -76,7 +76,7 @@ lapack_logical API_SUFFIX(LAPACKE_stp_nancheck)( int matrix_layout, char uplo, c
         return (lapack_logical) 0;
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_s_nancheck)( len, ap, 1 );
     }
 }
diff --git a/LAPACKE/utils/lapacke_str_nancheck.c b/LAPACKE/utils/lapacke_str_nancheck.c
index fbcaa2f627..052b174964 100644
--- a/LAPACKE/utils/lapacke_str_nancheck.c
+++ b/LAPACKE/utils/lapacke_str_nancheck.c
@@ -68,14 +68,14 @@ lapack_logical API_SUFFIX(LAPACKE_str_nancheck)( int matrix_layout, char uplo, c
     if( ( colmaj || lower ) && !( colmaj && lower ) ) {
         for( j = st; j < n; j++ ) {
             for( i = 0; i < MIN( j+1-st, lda ); i++ ) {
-                if( LAPACK_SISNAN( a[i+j*lda] ) )
+                if( LAPACK_SISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
     } else {
         for( j = 0; j < n-st; j++ ) {
             for( i = j+st; i < MIN( n, lda ); i++ ) {
-                if( LAPACK_SISNAN( a[i+j*lda] ) )
+                if( LAPACK_SISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
diff --git a/LAPACKE/utils/lapacke_stz_nancheck.c b/LAPACKE/utils/lapacke_stz_nancheck.c
index 903eef9b5d..c0759777b0 100644
--- a/LAPACKE/utils/lapacke_stz_nancheck.c
+++ b/LAPACKE/utils/lapacke_stz_nancheck.c
@@ -102,27 +102,27 @@ lapack_logical API_SUFFIX(LAPACKE_stz_nancheck)( int matrix_layout, char direct,
     }
 
     /* Initial offsets and sizes of triangular and rectangular parts */
-    lapack_int tri_offset = 0;
+    int64_t tri_offset = 0;
     lapack_int tri_n = MIN(m,n);
-    lapack_int rect_offset = -1;
+    int64_t rect_offset = -1;
     lapack_int rect_m = ( m > n ) ? m - n : m;
     lapack_int rect_n = ( n > m ) ? n - m : n;
 
     /* Fix offsets depending on the shape of the matrix */
     if( front ) {
         if( lower && m > n ) {
-            rect_offset = tri_n * ( !colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( !colmaj ? lda : 1 );
         } else if( !lower && n > m ) {
-            rect_offset = tri_n * ( colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( colmaj ? lda : 1 );
         }
     } else {
         if( m > n ) {
-            tri_offset = rect_m * ( !colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_m * ( !colmaj ? lda : 1 );
             if( !lower ) {
                 rect_offset = 0;
             }
         } else if( n > m ) {
-            tri_offset = rect_n * ( colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_n * ( colmaj ? lda : 1 );
             if( lower ) {
                 rect_offset = 0;
             }
diff --git a/LAPACKE/utils/lapacke_z_nancheck.c b/LAPACKE/utils/lapacke_z_nancheck.c
index c983876cfb..6a06a734ab 100644
--- a/LAPACKE/utils/lapacke_z_nancheck.c
+++ b/LAPACKE/utils/lapacke_z_nancheck.c
@@ -42,8 +42,8 @@ lapack_logical API_SUFFIX(LAPACKE_z_nancheck)( lapack_int n,
     if( incx == 0 ) return (lapack_logical) LAPACK_ZISNAN( x[0] );
     inc = ( incx > 0 ) ? incx : -incx ;
 
-    for( i = 0; i < n*inc; i+=inc ) {
-        if( LAPACK_ZISNAN( x[i] ) )
+    for( i = 0; i < n; i++ ) {
+        if( LAPACK_ZISNAN( x[(size_t)i*inc] ) )
             return (lapack_logical) 1;
     }
     return (lapack_logical) 0;
diff --git a/LAPACKE/utils/lapacke_zhp_nancheck.c b/LAPACKE/utils/lapacke_zhp_nancheck.c
index 152a1bf568..608788c6e2 100644
--- a/LAPACKE/utils/lapacke_zhp_nancheck.c
+++ b/LAPACKE/utils/lapacke_zhp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_zhp_nancheck)( lapack_int n,
                                       const lapack_complex_double *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_z_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_zpf_nancheck.c b/LAPACKE/utils/lapacke_zpf_nancheck.c
index 04c46f8ead..27f689d121 100644
--- a/LAPACKE/utils/lapacke_zpf_nancheck.c
+++ b/LAPACKE/utils/lapacke_zpf_nancheck.c
@@ -40,6 +40,6 @@
 lapack_logical API_SUFFIX(LAPACKE_zpf_nancheck)( lapack_int n,
                                       const lapack_complex_double *a )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_z_nancheck)( len, a, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_zpp_nancheck.c b/LAPACKE/utils/lapacke_zpp_nancheck.c
index ce4446a645..691f0c27d2 100644
--- a/LAPACKE/utils/lapacke_zpp_nancheck.c
+++ b/LAPACKE/utils/lapacke_zpp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_zpp_nancheck)( lapack_int n,
                                       const lapack_complex_double *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_z_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_zsp_nancheck.c b/LAPACKE/utils/lapacke_zsp_nancheck.c
index 648269757e..88764cf1ba 100644
--- a/LAPACKE/utils/lapacke_zsp_nancheck.c
+++ b/LAPACKE/utils/lapacke_zsp_nancheck.c
@@ -39,6 +39,6 @@
 lapack_logical API_SUFFIX(LAPACKE_zsp_nancheck)( lapack_int n,
                                       const lapack_complex_double *ap )
 {
-    lapack_int len = n*(n+1)/2;
+    lapack_int len = (lapack_int)(((size_t)n*(n+1))/2);
     return API_SUFFIX(LAPACKE_z_nancheck)( len, ap, 1 );
 }
diff --git a/LAPACKE/utils/lapacke_ztf_nancheck.c b/LAPACKE/utils/lapacke_ztf_nancheck.c
index d43e986350..81cc38fb2f 100644
--- a/LAPACKE/utils/lapacke_ztf_nancheck.c
+++ b/LAPACKE/utils/lapacke_ztf_nancheck.c
@@ -151,7 +151,7 @@ lapack_logical API_SUFFIX(LAPACKE_ztf_nancheck)( int matrix_layout, char transr,
         }
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_zge_nancheck)( LAPACK_COL_MAJOR, len, 1, a, len );
     }
 }
diff --git a/LAPACKE/utils/lapacke_ztp_nancheck.c b/LAPACKE/utils/lapacke_ztp_nancheck.c
index cd56224d88..fa34b6561f 100644
--- a/LAPACKE/utils/lapacke_ztp_nancheck.c
+++ b/LAPACKE/utils/lapacke_ztp_nancheck.c
@@ -76,7 +76,7 @@ lapack_logical API_SUFFIX(LAPACKE_ztp_nancheck)( int matrix_layout, char uplo, c
         return (lapack_logical) 0;
     } else {
         /* Non-unit case - just check whole array for NaNs. */
-        len = n*(n+1)/2;
+        len = (lapack_int)(((size_t)n*(n+1))/2);
         return API_SUFFIX(LAPACKE_z_nancheck)( len, ap, 1 );
     }
 }
diff --git a/LAPACKE/utils/lapacke_ztr_nancheck.c b/LAPACKE/utils/lapacke_ztr_nancheck.c
index 5c870a6461..8c5366bf81 100644
--- a/LAPACKE/utils/lapacke_ztr_nancheck.c
+++ b/LAPACKE/utils/lapacke_ztr_nancheck.c
@@ -68,14 +68,14 @@ lapack_logical API_SUFFIX(LAPACKE_ztr_nancheck)( int matrix_layout, char uplo, c
     if( ( colmaj || lower ) && !( colmaj && lower ) ) {
         for( j = st; j < n; j++ ) {
             for( i = 0; i < MIN( j+1-st, lda ); i++ ) {
-                if( LAPACK_ZISNAN( a[i+j*lda] ) )
+                if( LAPACK_ZISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
     } else {
         for( j = 0; j < n-st; j++ ) {
             for( i = j+st; i < MIN( n, lda ); i++ ) {
-                if( LAPACK_ZISNAN( a[i+j*lda] ) )
+                if( LAPACK_ZISNAN( a[i+(size_t)j*lda] ) )
                     return (lapack_logical) 1;
             }
         }
diff --git a/LAPACKE/utils/lapacke_ztz_nancheck.c b/LAPACKE/utils/lapacke_ztz_nancheck.c
index f316cf13d4..9b12d9321a 100644
--- a/LAPACKE/utils/lapacke_ztz_nancheck.c
+++ b/LAPACKE/utils/lapacke_ztz_nancheck.c
@@ -103,27 +103,27 @@ lapack_logical API_SUFFIX(LAPACKE_ztz_nancheck)( int matrix_layout, char direct,
     }
 
     /* Initial offsets and sizes of triangular and rectangular parts */
-    lapack_int tri_offset = 0;
+    int64_t tri_offset = 0;
     lapack_int tri_n = MIN(m,n);
-    lapack_int rect_offset = -1;
+    int64_t rect_offset = -1;
     lapack_int rect_m = ( m > n ) ? m - n : m;
     lapack_int rect_n = ( n > m ) ? n - m : n;
 
     /* Fix offsets depending on the shape of the matrix */
     if( front ) {
         if( lower && m > n ) {
-            rect_offset = tri_n * ( !colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( !colmaj ? lda : 1 );
         } else if( !lower && n > m ) {
-            rect_offset = tri_n * ( colmaj ? lda : 1 );
+            rect_offset = (int64_t)tri_n * ( colmaj ? lda : 1 );
         }
     } else {
         if( m > n ) {
-            tri_offset = rect_m * ( !colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_m * ( !colmaj ? lda : 1 );
             if( !lower ) {
                 rect_offset = 0;
             }
         } else if( n > m ) {
-            tri_offset = rect_n * ( colmaj ? lda : 1 );
+            tri_offset = (int64_t)rect_n * ( colmaj ? lda : 1 );
             if( lower ) {
                 rect_offset = 0;
             }