crypto/x509/x509_vfy.c:853: error: NULL_DEREFERENCE
  pointer `x` last assigned on line 846 could be null and is dereferenced at line 853, column 9.
Showing all 17 steps of the trace


crypto/x509/x509_vfy.c:841:1: start of procedure check_cert()
839.   }
840.   
841. > static int check_cert(X509_STORE_CTX *ctx)
842.   {
843.       X509_CRL *crl = NULL, *dcrl = NULL;

crypto/x509/x509_vfy.c:843:5: 
841.   static int check_cert(X509_STORE_CTX *ctx)
842.   {
843. >     X509_CRL *crl = NULL, *dcrl = NULL;
844.       int ok = 0;
845.       int cnum = ctx->error_depth;

crypto/x509/x509_vfy.c:844:5: 
842.   {
843.       X509_CRL *crl = NULL, *dcrl = NULL;
844. >     int ok = 0;
845.       int cnum = ctx->error_depth;
846.       X509 *x = sk_X509_value(ctx->chain, cnum);

crypto/x509/x509_vfy.c:845:5: 
843.       X509_CRL *crl = NULL, *dcrl = NULL;
844.       int ok = 0;
845. >     int cnum = ctx->error_depth;
846.       X509 *x = sk_X509_value(ctx->chain, cnum);
847.   

crypto/x509/x509_vfy.c:846:5: 
844.       int ok = 0;
845.       int cnum = ctx->error_depth;
846. >     X509 *x = sk_X509_value(ctx->chain, cnum);
847.   
848.       ctx->current_cert = x;

include/openssl/x509.h:99:1: start of procedure sk_X509_value()
  97.   typedef struct x509_cinf_st X509_CINF;
  98.   
  99. > DEFINE_STACK_OF(X509)
  100.   
  101.   /* This is used for a table of trust checking functions */

crypto/stack/stack.c:381:1: start of procedure OPENSSL_sk_value()
    379.   }
    380.   
    381. > void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    382.   {
    383.       if (st == NULL || i < 0 || i >= st->num)

crypto/stack/stack.c:383:9: Taking false branch
    381.   void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    382.   {
    383.       if (st == NULL || i < 0 || i >= st->num)
                   ^
    384.           return NULL;
    385.       return (void *)st->data[i];

crypto/stack/stack.c:383:23: Taking true branch
    381.   void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    382.   {
    383.       if (st == NULL || i < 0 || i >= st->num)
                                 ^
    384.           return NULL;
    385.       return (void *)st->data[i];

crypto/stack/stack.c:384:9: 
    382.   {
    383.       if (st == NULL || i < 0 || i >= st->num)
    384. >         return NULL;
    385.       return (void *)st->data[i];
    386.   }

crypto/stack/stack.c:386:1: return from a call to OPENSSL_sk_value
    384.           return NULL;
    385.       return (void *)st->data[i];
    386. > }
    387.   
    388.   void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)

include/openssl/x509.h:99:1: return from a call to sk_X509_value
  97.   typedef struct x509_cinf_st X509_CINF;
  98.   
  99. > DEFINE_STACK_OF(X509)
  100.   
  101.   /* This is used for a table of trust checking functions */

crypto/x509/x509_vfy.c:848:5: 
846.       X509 *x = sk_X509_value(ctx->chain, cnum);
847.   
848. >     ctx->current_cert = x;
849.       ctx->current_issuer = NULL;
850.       ctx->current_crl_score = 0;

crypto/x509/x509_vfy.c:849:5: 
847.   
848.       ctx->current_cert = x;
849. >     ctx->current_issuer = NULL;
850.       ctx->current_crl_score = 0;
851.       ctx->current_reasons = 0;

crypto/x509/x509_vfy.c:850:5: 
848.       ctx->current_cert = x;
849.       ctx->current_issuer = NULL;
850. >     ctx->current_crl_score = 0;
851.       ctx->current_reasons = 0;
852.   

crypto/x509/x509_vfy.c:851:5: 
849.       ctx->current_issuer = NULL;
850.       ctx->current_crl_score = 0;
851. >     ctx->current_reasons = 0;
852.   
853.       if (x->ex_flags & EXFLAG_PROXY)

crypto/x509/x509_vfy.c:853:9: 
851.       ctx->current_reasons = 0;
852.   
853. >     if (x->ex_flags & EXFLAG_PROXY)
854.           return 1;
855.   

static int check_cert(X509_STORE_CTX *ctx)
{
    X509_CRL *crl = NULL, *dcrl = NULL;
    int ok = 0;
    int cnum = ctx->error_depth;
    X509 *x = sk_X509_value(ctx->chain, cnum);
    ctx->current_cert = x;
    ctx->current_issuer = NULL;
    ctx->current_crl_score = 0;
    ctx->current_reasons = 0;
    if (x->ex_flags & EXFLAG_PROXY)
        return 1;
    while (ctx->current_reasons != CRLDP_ALL_REASONS) {
        unsigned int last_reasons = ctx->current_reasons;
        if (ctx->get_crl)
            ok = ctx->get_crl(ctx, &crl, x);
        else
            ok = get_crl_delta(ctx, &crl, &dcrl, x);
        if (!ok) {
            ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
            goto done;
        }
        ctx->current_crl = crl;
        ok = ctx->check_crl(ctx, crl);
        if (!ok)
            goto done;
        if (dcrl) {
            ok = ctx->check_crl(ctx, dcrl);
            if (!ok)
                goto done;
            ok = ctx->cert_crl(ctx, dcrl, x);
            if (!ok)
                goto done;
        } else
            ok = 1;
        if (ok != 2) {
            ok = ctx->cert_crl(ctx, crl, x);
            if (!ok)
                goto done;
        }
        X509_CRL_free(crl);
        X509_CRL_free(dcrl);
        crl = NULL;
        dcrl = NULL;
        if (last_reasons == ctx->current_reasons) {
            ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
            goto done;
        }
    }
 done:
    X509_CRL_free(crl);
    X509_CRL_free(dcrl);
    ctx->current_crl = NULL;
    return ok;
}
['static int check_cert(X509_STORE_CTX *ctx)\n{\n    X509_CRL *crl = NULL, *dcrl = NULL;\n    int ok = 0;\n    int cnum = ctx->error_depth;\n    X509 *x = sk_X509_value(ctx->chain, cnum);\n    ctx->current_cert = x;\n    ctx->current_issuer = NULL;\n    ctx->current_crl_score = 0;\n    ctx->current_reasons = 0;\n    if (x->ex_flags & EXFLAG_PROXY)\n        return 1;\n    while (ctx->current_reasons != CRLDP_ALL_REASONS) {\n        unsigned int last_reasons = ctx->current_reasons;\n        if (ctx->get_crl)\n            ok = ctx->get_crl(ctx, &crl, x);\n        else\n            ok = get_crl_delta(ctx, &crl, &dcrl, x);\n        if (!ok) {\n            ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);\n            goto done;\n        }\n        ctx->current_crl = crl;\n        ok = ctx->check_crl(ctx, crl);\n        if (!ok)\n            goto done;\n        if (dcrl) {\n            ok = ctx->check_crl(ctx, dcrl);\n            if (!ok)\n                goto done;\n            ok = ctx->cert_crl(ctx, dcrl, x);\n            if (!ok)\n                goto done;\n        } else\n            ok = 1;\n        if (ok != 2) {\n            ok = ctx->cert_crl(ctx, crl, x);\n            if (!ok)\n                goto done;\n        }\n        X509_CRL_free(crl);\n        X509_CRL_free(dcrl);\n        crl = NULL;\n        dcrl = NULL;\n        if (last_reasons == ctx->current_reasons) {\n            ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);\n            goto done;\n        }\n    }\n done:\n    X509_CRL_free(crl);\n    X509_CRL_free(dcrl);\n    ctx->current_crl = NULL;\n    return ok;\n}', 'DEFINE_STACK_OF(X509)', 'void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)\n{\n    if (st == NULL || i < 0 || i >= st->num)\n        return NULL;\n    return (void *)st->data[i];\n}']