From d0ffa6c9702228aa55c7d2f1c887bf547c46b283 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Tue, 26 Mar 2019 22:55:56 +0100
Subject: misrsom inverse: avoid division by zero

Fixes testcase https://oss-fuzz.com/testcase-detail/5768588923764736
of https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13894
---
 src/projections/misrsom.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'src/projections/misrsom.cpp')

diff --git a/src/projections/misrsom.cpp b/src/projections/misrsom.cpp
index c53f22a1..d16dd62d 100644
--- a/src/projections/misrsom.cpp
+++ b/src/projections/misrsom.cpp
@@ -151,10 +151,14 @@ static PJ_LP e_inverse (PJ_XY xy, PJ *P) {          /* Ellipsoidal, inverse */
         lamdp -= TOL;
     spp = sin(phidp);
     sppsq = spp * spp;
+    const double denom = 1. - sppsq * (1. + Q->u);
+    if( denom == 0.0 ) {
+        proj_errno_set(P, PJD_ERR_NON_CONVERGENT);
+        return proj_coord_error().lp;
+    }
     lamt = atan(((1. - sppsq * P->rone_es) * tan(lamdp) *
             Q->ca - spp * Q->sa * sqrt((1. + Q->q * dd) * (
-            1. - sppsq) - sppsq * Q->u) / cos(lamdp)) / (1. - sppsq
-            * (1. + Q->u)));
+            1. - sppsq) - sppsq * Q->u) / cos(lamdp)) / denom);
     sl = lamt >= 0. ? 1. : -1.;
     scl = cos(lamdp) >= 0. ? 1. : -1;
     lamt -= M_HALFPI * (1. - scl) * sl;
-- 
cgit v1.2.3


From 00980bf63fae6d350f425c44a648f33d7c09a931 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Fri, 26 Apr 2019 18:18:30 +0200
Subject: Prefix inverse and forward functions by their projection names

This is mostly to have better OSSFuzz report. Currently a lot
of bug summaries are like
`proj4/standard_fuzzer: Divide-by-zero in s_inverse`

By prefixing the projection name, we will get better reports, like
`Divide-by-zero in airy_s_inverse`

This also makes it slightly easier to set a breakpoint by
function name.
---
 src/projections/misrsom.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'src/projections/misrsom.cpp')

diff --git a/src/projections/misrsom.cpp b/src/projections/misrsom.cpp
index d16dd62d..09e2d8f3 100644
--- a/src/projections/misrsom.cpp
+++ b/src/projections/misrsom.cpp
@@ -62,7 +62,7 @@ static void seraz0(double lam, double mult, PJ *P) {
 }
 
 
-static PJ_XY e_forward (PJ_LP lp, PJ *P) {          /* Ellipsoidal, forward */
+static PJ_XY misrsom_e_forward (PJ_LP lp, PJ *P) {          /* Ellipsoidal, forward */
     PJ_XY xy = {0.0,0.0};
     struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
     int l, nn;
@@ -123,7 +123,7 @@ static PJ_XY e_forward (PJ_LP lp, PJ *P) {          /* Ellipsoidal, forward */
 }
 
 
-static PJ_LP e_inverse (PJ_XY xy, PJ *P) {          /* Ellipsoidal, inverse */
+static PJ_LP misrsom_e_inverse (PJ_XY xy, PJ *P) {          /* Ellipsoidal, inverse */
     PJ_LP lp = {0.0,0.0};
     struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
     int nn;
@@ -216,8 +216,8 @@ PJ *PROJECTION(misrsom) {
     Q->c1 /= 15.;
     Q->c3 /= 45.;
 
-    P->inv = e_inverse;
-    P->fwd = e_forward;
+    P->inv = misrsom_e_inverse;
+    P->fwd = misrsom_e_forward;
 
    return P;
 }
-- 
cgit v1.2.3