crypto/x509/x509_vfy.c:847: error: NULL_DEREFERENCE
  pointer `x` last assigned on line 840 could be null and is dereferenced at line 847, column 9.
Showing all 17 steps of the trace


crypto/x509/x509_vfy.c:835:1: start of procedure check_cert()
833.   }
834.   
835. > static int check_cert(X509_STORE_CTX *ctx)
836.   {
837.       X509_CRL *crl = NULL, *dcrl = NULL;

crypto/x509/x509_vfy.c:837:5: 
835.   static int check_cert(X509_STORE_CTX *ctx)
836.   {
837. >     X509_CRL *crl = NULL, *dcrl = NULL;
838.       int ok = 0;
839.       int cnum = ctx->error_depth;

crypto/x509/x509_vfy.c:838:5: 
836.   {
837.       X509_CRL *crl = NULL, *dcrl = NULL;
838. >     int ok = 0;
839.       int cnum = ctx->error_depth;
840.       X509 *x = sk_X509_value(ctx->chain, cnum);

crypto/x509/x509_vfy.c:839:5: 
837.       X509_CRL *crl = NULL, *dcrl = NULL;
838.       int ok = 0;
839. >     int cnum = ctx->error_depth;
840.       X509 *x = sk_X509_value(ctx->chain, cnum);
841.   

crypto/x509/x509_vfy.c:840:5: 
838.       int ok = 0;
839.       int cnum = ctx->error_depth;
840. >     X509 *x = sk_X509_value(ctx->chain, cnum);
841.   
842.       ctx->current_cert = x;

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

crypto/stack/stack.c:272:1: start of procedure OPENSSL_sk_value()
    270.   }
    271.   
    272. > void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    273.   {
    274.       if (st == NULL || i < 0 || i >= st->num)

crypto/stack/stack.c:274:9: Taking false branch
    272.   void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    273.   {
    274.       if (st == NULL || i < 0 || i >= st->num)
                   ^
    275.           return NULL;
    276.       return st->data[i];

crypto/stack/stack.c:274:23: Taking true branch
    272.   void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
    273.   {
    274.       if (st == NULL || i < 0 || i >= st->num)
                                 ^
    275.           return NULL;
    276.       return st->data[i];

crypto/stack/stack.c:275:9: 
    273.   {
    274.       if (st == NULL || i < 0 || i >= st->num)
    275. >         return NULL;
    276.       return st->data[i];
    277.   }

crypto/stack/stack.c:277:1: return from a call to OPENSSL_sk_value
    275.           return NULL;
    276.       return st->data[i];
    277. > }
    278.   
    279.   void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, void *value)

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

crypto/x509/x509_vfy.c:842:5: 
840.       X509 *x = sk_X509_value(ctx->chain, cnum);
841.   
842. >     ctx->current_cert = x;
843.       ctx->current_issuer = NULL;
844.       ctx->current_crl_score = 0;

crypto/x509/x509_vfy.c:843:5: 
841.   
842.       ctx->current_cert = x;
843. >     ctx->current_issuer = NULL;
844.       ctx->current_crl_score = 0;
845.       ctx->current_reasons = 0;

crypto/x509/x509_vfy.c:844:5: 
842.       ctx->current_cert = x;
843.       ctx->current_issuer = NULL;
844. >     ctx->current_crl_score = 0;
845.       ctx->current_reasons = 0;
846.   

crypto/x509/x509_vfy.c:845:5: 
843.       ctx->current_issuer = NULL;
844.       ctx->current_crl_score = 0;
845. >     ctx->current_reasons = 0;
846.   
847.       if (x->ex_flags & EXFLAG_PROXY)

crypto/x509/x509_vfy.c:847:9: 
845.       ctx->current_reasons = 0;
846.   
847. >     if (x->ex_flags & EXFLAG_PROXY)
848.           return 1;
849.   

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 st->data[i];\n}']