diff --git a/lib/smime/cmscinfo.c b/lib/smime/cmscinfo.c
index 08db662f80..453ccaadaa 100644
--- a/lib/smime/cmscinfo.c
+++ b/lib/smime/cmscinfo.c
@@ -51,6 +51,10 @@ NSS_CMSContentInfo_Destroy(NSSCMSContentInfo *cinfo)
 {
     SECOidTag kind;
 
+    if (cinfo == NULL) {
+        return;
+    }
+
     kind = NSS_CMSContentInfo_GetContentTypeTag(cinfo);
     switch (kind) {
         case SEC_OID_PKCS7_ENVELOPED_DATA:
@@ -86,6 +90,11 @@ NSSCMSContentInfo *
 NSS_CMSContentInfo_GetChildContentInfo(NSSCMSContentInfo *cinfo)
 {
     NSSCMSContentInfo *ccinfo = NULL;
+
+    if (cinfo == NULL) {
+        return NULL;
+    }
+
     SECOidTag tag = NSS_CMSContentInfo_GetContentTypeTag(cinfo);
     switch (tag) {
         case SEC_OID_PKCS7_SIGNED_DATA:
@@ -127,6 +136,9 @@ SECStatus
 NSS_CMSContentInfo_SetDontStream(NSSCMSContentInfo *cinfo, PRBool dontStream)
 {
     SECStatus rv;
+    if (cinfo == NULL) {
+        return SECFailure;
+    }
 
     rv = NSS_CMSContentInfo_Private_Init(cinfo);
     if (rv != SECSuccess) {
@@ -145,15 +157,20 @@ NSS_CMSContentInfo_SetContent(NSSCMSMessage *cmsg, NSSCMSContentInfo *cinfo,
                               SECOidTag type, void *ptr)
 {
     SECStatus rv;
+    if (cinfo == NULL || cmsg == NULL) {
+        return SECFailure;
+    }
 
     cinfo->contentTypeTag = SECOID_FindOIDByTag(type);
-    if (cinfo->contentTypeTag == NULL)
+    if (cinfo->contentTypeTag == NULL) {
         return SECFailure;
+    }
 
     /* do not copy the oid, just create a reference */
     rv = SECITEM_CopyItem(cmsg->poolp, &(cinfo->contentType), &(cinfo->contentTypeTag->oid));
-    if (rv != SECSuccess)
+    if (rv != SECSuccess) {
         return SECFailure;
+    }
 
     cinfo->content.pointer = ptr;
 
@@ -185,8 +202,9 @@ SECStatus
 NSS_CMSContentInfo_SetContent_Data(NSSCMSMessage *cmsg, NSSCMSContentInfo *cinfo,
                                    SECItem *data, PRBool detached)
 {
-    if (NSS_CMSContentInfo_SetContent(cmsg, cinfo, SEC_OID_PKCS7_DATA, (void *)data) != SECSuccess)
+    if (NSS_CMSContentInfo_SetContent(cmsg, cinfo, SEC_OID_PKCS7_DATA, (void *)data) != SECSuccess) {
         return SECFailure;
+    }
     if (detached) {
         cinfo->rawContent = NULL;
     }
@@ -230,6 +248,10 @@ NSS_CMSContentInfo_SetContent_EncryptedData(NSSCMSMessage *cmsg, NSSCMSContentIn
 void *
 NSS_CMSContentInfo_GetContent(NSSCMSContentInfo *cinfo)
 {
+    if (cinfo == NULL) {
+        return NULL;
+    }
+
     SECOidTag tag = cinfo->contentTypeTag
                         ? cinfo->contentTypeTag->offset
                         : SEC_OID_UNKNOWN;
@@ -260,6 +282,10 @@ NSS_CMSContentInfo_GetInnerContent(NSSCMSContentInfo *cinfo)
     SECOidTag tag;
     SECItem *pItem = NULL;
 
+    if (cinfo == NULL) {
+        return NULL;
+    }
+
     tag = NSS_CMSContentInfo_GetContentTypeTag(cinfo);
     if (NSS_CMSType_IsData(tag)) {
         pItem = cinfo->content.data;
@@ -282,6 +308,10 @@ NSS_CMSContentInfo_GetInnerContent(NSSCMSContentInfo *cinfo)
 SECOidTag
 NSS_CMSContentInfo_GetContentTypeTag(NSSCMSContentInfo *cinfo)
 {
+    if (cinfo == NULL) {
+        return SEC_OID_UNKNOWN;
+    }
+
     if (cinfo->contentTypeTag == NULL)
         cinfo->contentTypeTag = SECOID_FindOID(&(cinfo->contentType));
 
@@ -294,11 +324,17 @@ NSS_CMSContentInfo_GetContentTypeTag(NSSCMSContentInfo *cinfo)
 SECItem *
 NSS_CMSContentInfo_GetContentTypeOID(NSSCMSContentInfo *cinfo)
 {
-    if (cinfo->contentTypeTag == NULL)
+    if (cinfo == NULL) {
+        return NULL;
+    }
+
+    if (cinfo->contentTypeTag == NULL) {
         cinfo->contentTypeTag = SECOID_FindOID(&(cinfo->contentType));
+    }
 
-    if (cinfo->contentTypeTag == NULL)
+    if (cinfo->contentTypeTag == NULL) {
         return NULL;
+    }
 
     return &(cinfo->contentTypeTag->oid);
 }
@@ -310,8 +346,13 @@ NSS_CMSContentInfo_GetContentTypeOID(NSSCMSContentInfo *cinfo)
 SECOidTag
 NSS_CMSContentInfo_GetContentEncAlgTag(NSSCMSContentInfo *cinfo)
 {
-    if (cinfo->contentEncAlgTag == SEC_OID_UNKNOWN)
+    if (cinfo == NULL) {
+        return SEC_OID_UNKNOWN;
+    }
+
+    if (cinfo->contentEncAlgTag == SEC_OID_UNKNOWN) {
         cinfo->contentEncAlgTag = SECOID_GetAlgorithmTag(&(cinfo->contentEncAlg));
+    }
 
     return cinfo->contentEncAlgTag;
 }
@@ -322,6 +363,10 @@ NSS_CMSContentInfo_GetContentEncAlgTag(NSSCMSContentInfo *cinfo)
 SECAlgorithmID *
 NSS_CMSContentInfo_GetContentEncAlg(NSSCMSContentInfo *cinfo)
 {
+    if (cinfo == NULL) {
+        return NULL;
+    }
+
     return &(cinfo->contentEncAlg);
 }
 
@@ -330,10 +375,14 @@ NSS_CMSContentInfo_SetContentEncAlg(PLArenaPool *poolp, NSSCMSContentInfo *cinfo
                                     SECOidTag bulkalgtag, SECItem *parameters, int keysize)
 {
     SECStatus rv;
+    if (cinfo == NULL) {
+        return SECFailure;
+    }
 
     rv = SECOID_SetAlgorithmID(poolp, &(cinfo->contentEncAlg), bulkalgtag, parameters);
-    if (rv != SECSuccess)
+    if (rv != SECSuccess) {
         return SECFailure;
+    }
     cinfo->keysize = keysize;
     return SECSuccess;
 }
@@ -343,27 +392,42 @@ NSS_CMSContentInfo_SetContentEncAlgID(PLArenaPool *poolp, NSSCMSContentInfo *cin
                                       SECAlgorithmID *algid, int keysize)
 {
     SECStatus rv;
+    if (cinfo == NULL) {
+        return SECFailure;
+    }
 
     rv = SECOID_CopyAlgorithmID(poolp, &(cinfo->contentEncAlg), algid);
-    if (rv != SECSuccess)
+    if (rv != SECSuccess) {
         return SECFailure;
-    if (keysize >= 0)
+    }
+    if (keysize >= 0) {
         cinfo->keysize = keysize;
+    }
     return SECSuccess;
 }
 
 void
 NSS_CMSContentInfo_SetBulkKey(NSSCMSContentInfo *cinfo, PK11SymKey *bulkkey)
 {
-    cinfo->bulkkey = PK11_ReferenceSymKey(bulkkey);
-    cinfo->keysize = PK11_GetKeyStrength(cinfo->bulkkey, &(cinfo->contentEncAlg));
+    if (cinfo == NULL) {
+        return;
+    }
+
+    if (bulkkey == NULL) {
+        cinfo->bulkkey = NULL;
+        cinfo->keysize = 0;
+    } else {
+        cinfo->bulkkey = PK11_ReferenceSymKey(bulkkey);
+        cinfo->keysize = PK11_GetKeyStrength(cinfo->bulkkey, &(cinfo->contentEncAlg));
+    }
 }
 
 PK11SymKey *
 NSS_CMSContentInfo_GetBulkKey(NSSCMSContentInfo *cinfo)
 {
-    if (cinfo->bulkkey == NULL)
+    if (cinfo == NULL || cinfo->bulkkey == NULL) {
         return NULL;
+    }
 
     return PK11_ReferenceSymKey(cinfo->bulkkey);
 }
@@ -371,5 +435,9 @@ NSS_CMSContentInfo_GetBulkKey(NSSCMSContentInfo *cinfo)
 int
 NSS_CMSContentInfo_GetBulkKeySize(NSSCMSContentInfo *cinfo)
 {
+    if (cinfo == NULL) {
+        return 0;
+    }
+
     return cinfo->keysize;
 }
diff --git a/lib/smime/cmsdigdata.c b/lib/smime/cmsdigdata.c
index 9ea22702e1..a249686bbe 100644
--- a/lib/smime/cmsdigdata.c
+++ b/lib/smime/cmsdigdata.c
@@ -56,7 +56,9 @@ void
 NSS_CMSDigestedData_Destroy(NSSCMSDigestedData *digd)
 {
     /* everything's in a pool, so don't worry about the storage */
-    NSS_CMSContentInfo_Destroy(&(digd->contentInfo));
+    if (digd != NULL) {
+        NSS_CMSContentInfo_Destroy(&(digd->contentInfo));
+    }
     return;
 }
 
diff --git a/lib/smime/cmsencdata.c b/lib/smime/cmsencdata.c
index d2fc3358b9..f2a27468ec 100644
--- a/lib/smime/cmsencdata.c
+++ b/lib/smime/cmsencdata.c
@@ -87,7 +87,9 @@ void
 NSS_CMSEncryptedData_Destroy(NSSCMSEncryptedData *encd)
 {
     /* everything's in a pool, so don't worry about the storage */
-    NSS_CMSContentInfo_Destroy(&(encd->contentInfo));
+    if (encd != NULL) {
+        NSS_CMSContentInfo_Destroy(&(encd->contentInfo));
+    }
     return;
 }
 
diff --git a/lib/smime/cmsenvdata.c b/lib/smime/cmsenvdata.c
index d5d5c41239..95b3fb98be 100644
--- a/lib/smime/cmsenvdata.c
+++ b/lib/smime/cmsenvdata.c
@@ -144,6 +144,11 @@ NSS_CMSEnvelopedData_Encode_BeforeStart(NSSCMSEnvelopedData *envd)
     poolp = envd->cmsg->poolp;
     cinfo = &(envd->contentInfo);
 
+    if (cinfo == NULL) {
+        PORT_SetError(SEC_ERROR_BAD_DATA);
+        goto loser;
+    }
+
     recipientinfos = envd->recipientInfos;
     if (recipientinfos == NULL) {
         PORT_SetError(SEC_ERROR_BAD_DATA);
diff --git a/lib/smime/cmsmessage.c b/lib/smime/cmsmessage.c
index f41a432b19..366b71abad 100644
--- a/lib/smime/cmsmessage.c
+++ b/lib/smime/cmsmessage.c
@@ -96,6 +96,9 @@ NSS_CMSMessage_SetEncodingParams(NSSCMSMessage *cmsg,
 void
 NSS_CMSMessage_Destroy(NSSCMSMessage *cmsg)
 {
+    if (cmsg == NULL)
+        return;
+
     PORT_Assert(cmsg->refCount > 0);
     if (cmsg->refCount <= 0) { /* oops */
         return;
diff --git a/lib/smime/cmsudf.c b/lib/smime/cmsudf.c
index 3ef4268d4e..5c8a81e6df 100644
--- a/lib/smime/cmsudf.c
+++ b/lib/smime/cmsudf.c
@@ -239,7 +239,7 @@ NSS_CMSGenericWrapperData_Destroy(SECOidTag type, NSSCMSGenericWrapperData *gd)
 {
     const nsscmstypeInfo *typeInfo = nss_cmstype_lookup(type);
 
-    if (typeInfo && typeInfo->destroy) {
+    if (typeInfo && (typeInfo->destroy) && (gd != NULL)) {
         (*typeInfo->destroy)(gd);
     }
 }