crypto/x509/x509_vfy.c:581: error: NULL_DEREFERENCE
  pointer `x` last assigned on line 579 could be null and is dereferenced at line 581, column 17.
Showing all 23 steps of the trace


crypto/x509/x509_vfy.c:539:1: start of procedure check_chain_extensions()
537.    */
538.   
539. > static int check_chain_extensions(X509_STORE_CTX *ctx)
540.   {
541.       int i, ok = 0, must_be_ca, plen = 0;

crypto/x509/x509_vfy.c:541:5: 
539.   static int check_chain_extensions(X509_STORE_CTX *ctx)
540.   {
541. >     int i, ok = 0, must_be_ca, plen = 0;
542.       X509 *x;
543.       int (*cb) (int xok, X509_STORE_CTX *xctx);

crypto/x509/x509_vfy.c:544:5: 
542.       X509 *x;
543.       int (*cb) (int xok, X509_STORE_CTX *xctx);
544. >     int proxy_path_length = 0;
545.       int purpose;
546.       int allow_proxy_certs;

crypto/x509/x509_vfy.c:547:5: 
545.       int purpose;
546.       int allow_proxy_certs;
547. >     cb = ctx->verify_cb;
548.   
549.       /*-

crypto/x509/x509_vfy.c:558:5: 
556.        *     all certificates in the chain except the leaf certificate.
557.        */
558. >     must_be_ca = -1;
559.   
560.       /* CRL path validation */

crypto/x509/x509_vfy.c:561:9: Taking false branch
559.   
560.       /* CRL path validation */
561.       if (ctx->parent) {
               ^
562.           allow_proxy_certs = 0;
563.           purpose = X509_PURPOSE_CRL_SIGN;

crypto/x509/x509_vfy.c:566:17: Condition is true
564.       } else {
565.           allow_proxy_certs =
566.               ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
                       ^
567.           /*
568.            * A hack to keep people who don't want to modify their software

crypto/x509/x509_vfy.c:566:13: 
564.       } else {
565.           allow_proxy_certs =
566. >             ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
567.           /*
568.            * A hack to keep people who don't want to modify their software

crypto/x509/x509_vfy.c:565:9: 
563.           purpose = X509_PURPOSE_CRL_SIGN;
564.       } else {
565. >         allow_proxy_certs =
566.               ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
567.           /*

crypto/x509/x509_vfy.c:571:13: Taking false branch
569.            * happy
570.            */
571.           if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
                   ^
572.               allow_proxy_certs = 1;
573.           purpose = ctx->param->purpose;

crypto/x509/x509_vfy.c:573:9: 
571.           if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
572.               allow_proxy_certs = 1;
573. >         purpose = ctx->param->purpose;
574.       }
575.   

crypto/x509/x509_vfy.c:577:10: 
575.   
576.       /* Check all untrusted certificates */
577. >     for (i = 0; i < ctx->last_untrusted; i++) {
578.           int ret;
579.           x = sk_X509_value(ctx->chain, i);

crypto/x509/x509_vfy.c:577:17: Loop condition is true. Entering loop body
575.   
576.       /* Check all untrusted certificates */
577.       for (i = 0; i < ctx->last_untrusted; i++) {
                       ^
578.           int ret;
579.           x = sk_X509_value(ctx->chain, i);

crypto/x509/x509_vfy.c:579:13: Condition is true
577.       for (i = 0; i < ctx->last_untrusted; i++) {
578.           int ret;
579.           x = sk_X509_value(ctx->chain, i);
                   ^
580.           if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
581.               && (x->ex_flags & EXFLAG_CRITICAL)) {

crypto/x509/x509_vfy.c:579:9: 
577.       for (i = 0; i < ctx->last_untrusted; i++) {
578.           int ret;
579. >         x = sk_X509_value(ctx->chain, i);
580.           if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
581.               && (x->ex_flags & EXFLAG_CRITICAL)) {

crypto/stack/stack.c:326:1: start of procedure sk_value()
  324.   }
  325.   
  326. > void *sk_value(const _STACK *st, int i)
  327.   {
  328.       if (!st || (i < 0) || (i >= st->num))

crypto/stack/stack.c:328:10: Taking false branch
  326.   void *sk_value(const _STACK *st, int i)
  327.   {
  328.       if (!st || (i < 0) || (i >= st->num))
                  ^
  329.           return NULL;
  330.       return st->data[i];

crypto/stack/stack.c:328:17: Taking false branch
  326.   void *sk_value(const _STACK *st, int i)
  327.   {
  328.       if (!st || (i < 0) || (i >= st->num))
                         ^
  329.           return NULL;
  330.       return st->data[i];

crypto/stack/stack.c:328:28: Taking true branch
  326.   void *sk_value(const _STACK *st, int i)
  327.   {
  328.       if (!st || (i < 0) || (i >= st->num))
                                    ^
  329.           return NULL;
  330.       return st->data[i];

crypto/stack/stack.c:329:9: 
  327.   {
  328.       if (!st || (i < 0) || (i >= st->num))
  329. >         return NULL;
  330.       return st->data[i];
  331.   }

crypto/stack/stack.c:331:1: return from a call to sk_value
  329.           return NULL;
  330.       return st->data[i];
  331. > }
  332.   
  333.   void *sk_set(_STACK *st, int i, void *value)

crypto/x509/x509_vfy.c:580:15: Taking true branch
578.           int ret;
579.           x = sk_X509_value(ctx->chain, i);
580.           if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
                     ^
581.               && (x->ex_flags & EXFLAG_CRITICAL)) {
582.               ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;

crypto/x509/x509_vfy.c:581:17: 
579.           x = sk_X509_value(ctx->chain, i);
580.           if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
581. >             && (x->ex_flags & EXFLAG_CRITICAL)) {
582.               ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
583.               ctx->error_depth = i;
