[PATCH] cifs: improve check for search entry going beyond end of SMB transact

Signed-off-by: Steve French (sfrench@us.ibm.com)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 102 insertions, 68 deletions

diff --git a/fs/cifs/README b/fs/cifs/README
index 48c37a6e9c3f..bec7b3fc8a72 100644
--- a/fs/cifs/README
+++ b/fs/cifs/README
@@ -420,7 +420,7 @@ Misc /proc/fs/cifs Flags and Debug Info
 =======================================
 Informational pseudo-files:
 DebugData               Displays information about active CIFS sessions
-                        and shares.
+                        and shares, as well as the cifs.ko version.
 Stats                   Lists summary resource usage information as well as per
                         share statistics, if CONFIG_CIFS_STATS in enabled
                         in the kernel configuration.
@@ -477,7 +477,7 @@ and for more extensive tracing including the start of smb requests and responses
 Two other experimental features are under development and to test 
 require enabling CONFIG_CIFS_EXPERIMENTAL
 
-        More efficient write operations and SMB buffer handling
+        More efficient write operations
 
         DNOTIFY fcntl: needed for support of directory change 
                             notification and perhaps later for file leases)
@@ -495,8 +495,8 @@ returned success.
         
 Also note that "cat /proc/fs/cifs/DebugData" will display information about 
 the active sessions and the shares that are mounted.  Note: NTLMv2 enablement 
-will not work since they its implementation is not quite complete yet.
-Do not alter these configuration values unless you are doing specific testing.  
+will not work since its implementation is not quite complete yet. Do not alter
+the ExtendedSecurity configuration value unless you are doing specific testing.
 Enabling extended security works to Windows 2000 Workstations and XP but not to 
 Windows 2000 server or Samba since it does not usually send "raw NTLMSSP" 
 (instead it sends NTLMSSP encapsulated in SPNEGO/GSSAPI, which support is not 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index b102ddb977ca..834297f7b5e1 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -75,7 +75,8 @@ static void mark_open_files_invalid(struct cifsTconInfo * pTcon)
                 }
         }
         write_unlock(&GlobalSMBSeslock);
-        /* BB Add call to invalidate_inodes(sb) for all superblocks mounted to this tcon */
+        /* BB Add call to invalidate_inodes(sb) for all superblocks mounted
+           to this tcon */
 }
 
 /* If the return code is zero, this function must fill in request_buf pointer */
@@ -92,8 +93,8 @@ small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                 if((tcon->ses) && (tcon->ses->server)){
                         struct nls_table *nls_codepage;
                                 /* Give Demultiplex thread up to 10 seconds to 
-                                        reconnect, should be greater than cifs socket
-                                        timeout which is 7 seconds */
+                                   reconnect, should be greater than cifs socket
+                                   timeout which is 7 seconds */
                         while(tcon->ses->server->tcpStatus == CifsNeedReconnect) {
                                 wait_event_interruptible_timeout(tcon->ses->server->response_q,
                                         (tcon->ses->server->tcpStatus == CifsGood), 10 * HZ);
@@ -103,8 +104,9 @@ small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                                            (tcon->ses->status == CifsExiting)) {
                                                 cFYI(1,("gave up waiting on reconnect in smb_init"));
                                                 return -EHOSTDOWN;
-                                        } /* else "hard" mount - keep retrying until 
-                                        process is killed or server comes back up */
+                                        } /* else "hard" mount - keep retrying
+                                             until process is killed or server
+                                             comes back on-line */
                                 } else /* TCP session is reestablished now */
                                         break;
                                  
@@ -115,23 +117,24 @@ small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                 simultaneously reconnect the same SMB session */
                         down(&tcon->ses->sesSem);
                         if(tcon->ses->status == CifsNeedReconnect)
-                                rc = cifs_setup_session(0, tcon->ses, nls_codepage);
+                                rc = cifs_setup_session(0, tcon->ses, 
+                                                        nls_codepage);
                         if(!rc && (tcon->tidStatus == CifsNeedReconnect)) {
                                 mark_open_files_invalid(tcon);
-                                rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon,
-                                        nls_codepage);
+                                rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon
+                                        , nls_codepage);
                                 up(&tcon->ses->sesSem);
                                 if(rc == 0)
                                         atomic_inc(&tconInfoReconnectCount);
 
                                 cFYI(1, ("reconnect tcon rc = %d", rc));
                                 /* Removed call to reopen open files here - 
-                                        it is safer (and faster) to reopen files
-                                        one at a time as needed in read and write */
+                                   it is safer (and faster) to reopen files
+                                   one at a time as needed in read and write */
 
                                 /* Check if handle based operation so we 
-                                        know whether we can continue or not without
-                                        returning to caller to reset file handle */
+                                   know whether we can continue or not without
+                                   returning to caller to reset file handle */
                                 switch(smb_command) {
                                         case SMB_COM_READ_ANDX:
                                         case SMB_COM_WRITE_ANDX:
@@ -184,20 +187,22 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
         if(tcon) {
                 if((tcon->ses) && (tcon->ses->server)){
                         struct nls_table *nls_codepage;
-                                /* Give Demultiplex thread up to 10 seconds to 
-                                        reconnect, should be greater than cifs socket
-                                        timeout which is 7 seconds */
+                                /* Give Demultiplex thread up to 10 seconds to
+                                   reconnect, should be greater than cifs socket
+                                   timeout which is 7 seconds */
                         while(tcon->ses->server->tcpStatus == CifsNeedReconnect) {
                                 wait_event_interruptible_timeout(tcon->ses->server->response_q,
                                         (tcon->ses->server->tcpStatus == CifsGood), 10 * HZ);
-                                if(tcon->ses->server->tcpStatus == CifsNeedReconnect) {
+                                if(tcon->ses->server->tcpStatus == 
+                                                CifsNeedReconnect) {
                                         /* on "soft" mounts we wait once */
                                         if((tcon->retry == FALSE) || 
                                            (tcon->ses->status == CifsExiting)) {
                                                 cFYI(1,("gave up waiting on reconnect in smb_init"));
                                                 return -EHOSTDOWN;
-                                        } /* else "hard" mount - keep retrying until 
-                                        process is killed or server comes back up */
+                                        } /* else "hard" mount - keep retrying
+                                             until process is killed or server
+                                             comes on-line */
                                 } else /* TCP session is reestablished now */
                                         break;
                                  
@@ -208,23 +213,24 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
                 simultaneously reconnect the same SMB session */
                         down(&tcon->ses->sesSem);
                         if(tcon->ses->status == CifsNeedReconnect)
-                                rc = cifs_setup_session(0, tcon->ses, nls_codepage);
+                                rc = cifs_setup_session(0, tcon->ses, 
+                                                        nls_codepage);
                         if(!rc && (tcon->tidStatus == CifsNeedReconnect)) {
                                 mark_open_files_invalid(tcon);
-                                rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon,
-                                        nls_codepage);
+                                rc = CIFSTCon(0, tcon->ses, tcon->treeName,
+                                              tcon, nls_codepage);
                                 up(&tcon->ses->sesSem);
                                 if(rc == 0)
                                         atomic_inc(&tconInfoReconnectCount);
 
                                 cFYI(1, ("reconnect tcon rc = %d", rc));
                                 /* Removed call to reopen open files here - 
-                                        it is safer (and faster) to reopen files
-                                        one at a time as needed in read and write */
+                                   it is safer (and faster) to reopen files
+                                   one at a time as needed in read and write */
 
                                 /* Check if handle based operation so we 
-                                        know whether we can continue or not without
-                                        returning to caller to reset file handle */
+                                   know whether we can continue or not without
+                                   returning to caller to reset file handle */
                                 switch(smb_command) {
                                         case SMB_COM_READ_ANDX:
                                         case SMB_COM_WRITE_ANDX:
@@ -286,7 +292,8 @@ static int validate_t2(struct smb_t2_rsp * pSMB)
                         if(total_size < 512) {
                                 total_size+=le16_to_cpu(pSMB->t2_rsp.DataCount);
                                 /* BCC le converted in SendReceive */
-                                pBCC = (pSMB->hdr.WordCount * 2) + sizeof(struct smb_hdr) + 
+                                pBCC = (pSMB->hdr.WordCount * 2) + 
+                                        sizeof(struct smb_hdr) +
                                         (char *)pSMB;
                                 if((total_size <= (*(u16 *)pBCC)) && 
                                    (total_size < 
@@ -337,8 +344,10 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
                          (struct smb_hdr *) pSMBr, &bytes_returned, 0);
         if (rc == 0) {
                 server->secMode = pSMBr->SecurityMode;  
-                server->secType = NTLM; /* BB override default for NTLMv2 or krb*/
-                /* one byte - no need to convert this or EncryptionKeyLen from le,*/
+                server->secType = NTLM; /* BB override default for 
+                                           NTLMv2 or kerberos v5 */
+                /* one byte - no need to convert this or EncryptionKeyLen
+                   from little endian */
                 server->maxReq = le16_to_cpu(pSMBr->MaxMpxCount);
                 /* probably no need to store and check maxvcs */
                 server->maxBuf =
@@ -374,7 +383,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
                                                 pSMBr->u.extended_response.
                                                 GUID, 16) != 0) {
                                                 cFYI(1,
-                                                        ("UID of server does not match previous connection to same ip address"));
+                                                     ("UID of server does not match previous connection to same ip address"));
                                                 memcpy(server->
                                                         server_GUID,
                                                         pSMBr->u.
@@ -454,7 +463,8 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
                 up(&tcon->tconSem);
                 return -EIO;
         }
-        rc = small_smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon, (void **)&smb_buffer);
+        rc = small_smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon, 
+                            (void **)&smb_buffer);
         if (rc) {
                 up(&tcon->tconSem);
                 return rc;
@@ -559,7 +569,7 @@ DelFileRetry:
                                      PATH_MAX, nls_codepage, remap);
                 name_len++;     /* trailing null */
                 name_len *= 2;
-        } else {                /* BB improve the check for buffer overruns BB */
+        } else {                /* BB improve check for buffer overruns BB */
                 name_len = strnlen(fileName, PATH_MAX);
                 name_len++;     /* trailing null */
                 strncpy(pSMB->fileName, fileName, name_len);
@@ -609,7 +619,7 @@ RmDirRetry:
                                          PATH_MAX, nls_codepage, remap);
                 name_len++;     /* trailing null */
                 name_len *= 2;
-        } else {                /* BB improve the check for buffer overruns BB */
+        } else {                /* BB improve check for buffer overruns BB */
                 name_len = strnlen(dirName, PATH_MAX);
                 name_len++;     /* trailing null */
                 strncpy(pSMB->DirName, dirName, name_len);
@@ -657,7 +667,7 @@ MkDirRetry:
                                             PATH_MAX, nls_codepage, remap);
                 name_len++;     /* trailing null */
                 name_len *= 2;
-        } else {                /* BB improve the check for buffer overruns BB */
+        } else {                /* BB improve check for buffer overruns BB */
                 name_len = strnlen(name, PATH_MAX);
                 name_len++;     /* trailing null */
                 strncpy(pSMB->DirName, name, name_len);
@@ -712,7 +722,7 @@ openRetry:
                 name_len++;     /* trailing null */
                 name_len *= 2;
                 pSMB->NameLength = cpu_to_le16(name_len);
-        } else {                /* BB improve the check for buffer overruns BB */
+        } else {                /* BB improve check for buffer overruns BB */
                 count = 0;      /* no pad */
                 name_len = strnlen(fileName, PATH_MAX);
                 name_len++;     /* trailing null */
@@ -741,7 +751,8 @@ openRetry:
         pSMB->ShareAccess = cpu_to_le32(FILE_SHARE_ALL);
         pSMB->CreateDisposition = cpu_to_le32(openDisposition);
         pSMB->CreateOptions = cpu_to_le32(create_options);
-        pSMB->ImpersonationLevel = cpu_to_le32(SECURITY_IMPERSONATION); /* BB ??*/
+        /* BB Expirement with various impersonation levels and verify */
+        pSMB->ImpersonationLevel = cpu_to_le32(SECURITY_IMPERSONATION);
         pSMB->SecurityFlags =
             SECURITY_CONTEXT_TRACKING | SECURITY_EFFECTIVE_ONLY;
 
@@ -755,7 +766,7 @@ openRetry:
         if (rc) {
                 cFYI(1, ("Error in Open = %d", rc));
         } else {
-                *pOplock = pSMBr->OplockLevel;  /* one byte no need to le_to_cpu */
+                *pOplock = pSMBr->OplockLevel; /* 1 byte no need to le_to_cpu */
                 *netfid = pSMBr->Fid;   /* cifs fid stays in le */
                 /* Let caller know file was created so we can set the mode. */
                 /* Do we care about the CreateAction in any other cases? */
@@ -2504,7 +2515,9 @@ findFirstRetry:
                         psrch_inf->srch_entries_start = 
                                 (char *) &pSMBr->hdr.Protocol + 
                                         le16_to_cpu(pSMBr->t2.DataOffset);
-
+/* if(le16_to_cpu(pSMBr->t2.DataCount) != le16_to_cpu(pSMBr->t2.TotalDataCount)) {  
+        cERROR(1,("DC: %d TDC: %d",pSMBr->t2.DataCount,pSMBr->t2.TotalDataCount));
+} */ /* BB removeme BB */
                         parms = (T2_FFIRST_RSP_PARMS *)((char *) &pSMBr->hdr.Protocol +
                                le16_to_cpu(pSMBr->t2.ParameterOffset));
 
@@ -2516,7 +2529,7 @@ findFirstRetry:
                         psrch_inf->entries_in_buffer  = le16_to_cpu(parms->SearchCount);
                         psrch_inf->index_of_last_entry = 
                                 psrch_inf->entries_in_buffer;
-/*cFYI(1,("entries in buf %d index_of_last %d",psrch_inf->entries_in_buffer,psrch_inf->index_of_last_entry));  */
+/*cFYI(1,("entries in buf %d index_of_last %d",psrch_inf->entries_in_buffer,psrch_inf->index_of_last_entry));  */ /* BB removeme BB */
                         *pnetfid = parms->SearchHandle;
                 } else {
                         cifs_buf_release(pSMB);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8a8aa785e7b7..d5d49b584db4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -157,9 +157,10 @@ cifs_reconnect(struct TCP_Server_Info *server)
                                         qhead);
                 if(mid_entry) {
                         if(mid_entry->midState == MID_REQUEST_SUBMITTED) {
-                                /* Mark other intransit requests as needing retry so 
-                                  we do not immediately mark the session bad again 
-                                  (ie after we reconnect below) as they timeout too */
+                                /* Mark other intransit requests as needing
+                                   retry so we do not immediately mark the
+                                   session bad again (ie after we reconnect
+                                   below) as they timeout too */
                                 mid_entry->midState = MID_RETRY_NEEDED;
                         }
                 }
@@ -278,9 +279,10 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                 } else if (length <= 0) {
                         if(server->tcpStatus == CifsNew) {
                                 cFYI(1,("tcp session abended prematurely (after SMBnegprot)"));
-                                /* some servers kill tcp session rather than returning
-                                        smb negprot error in which case reconnecting here is
-                                        not going to help - return error to mount */
+                                /* some servers kill the TCP session rather than
+                                   returning an SMB negprot error, in which
+                                   case reconnecting here is not going to help,
+                                   and so simply return error to mount */
                                 break;
                         }
                         if(length == -EINTR) { 
@@ -296,15 +298,19 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                         pdu_length = ntohl(smb_buffer->smb_buf_length);
                 /* Only read pdu_length after below checks for too short (due
                    to e.g. int overflow) and too long ie beyond end of buf */
-                        cFYI(1,("rfc1002 length(big endian)0x%x)", pdu_length+4));
+                        cFYI(1,("rfc1002 length(big endian)0x%x)",
+                                pdu_length+4));
 
                         temp = (char *) smb_buffer;
                         if (temp[0] == (char) RFC1002_SESSION_KEEP_ALIVE) {
                                 cFYI(0,("Received 4 byte keep alive packet"));
-                        } else if (temp[0] == (char) RFC1002_POSITIVE_SESSION_RESPONSE) {
+                        } else if (temp[0] == 
+                                (char) RFC1002_POSITIVE_SESSION_RESPONSE) {
                                         cFYI(1,("Good RFC 1002 session rsp"));
-                        } else if (temp[0] == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
-                                /* we get this from Windows 98 instead of error on SMB negprot response */
+                        } else if (temp[0] == 
+                                (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
+                                /* we get this from Windows 98 instead of 
+                                   an error on SMB negprot response */
                                 cFYI(1,("Negative RFC 1002 Session Response Error 0x%x)",temp[4]));
                                 if(server->tcpStatus == CifsNew) {
                                         /* if nack on negprot (rather than 
@@ -320,7 +326,8 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                         connected to port 139 (the NACK is 
                                         since we do not begin with RFC1001
                                         session initialize frame) */
-                                        server->addr.sockAddr.sin_port = htons(CIFS_PORT);
+                                        server->addr.sockAddr.sin_port = 
+                                                htons(CIFS_PORT);
                                         cifs_reconnect(server);
                                         csocket = server->ssocket;
                                         wake_up(&server->response_q);
@@ -333,8 +340,9 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                 csocket = server->ssocket;
                                 continue;
                         } else {
-                                if((pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)
-                                    || (pdu_length < sizeof (struct smb_hdr) - 1 - 4)) {
+                                if((pdu_length > CIFSMaxBufSize + 
+                                        MAX_CIFS_HDR_SIZE - 4) ||
+                                    (pdu_length < sizeof (struct smb_hdr) - 1 - 4)) {
                                         cERROR(1,
                                             ("Invalid size SMB length %d and pdu_length %d",
                                                 length, pdu_length+4));
@@ -377,6 +385,8 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                         continue;
                                 }
 
+                                /* BB FIXME - add checkTrans2SMBSecondary() */
+
                                 task_to_wake = NULL;
                                 spin_lock(&GlobalMid_Lock);
                                 list_for_each(tmp, &server->pending_mid_q) {
@@ -408,7 +418,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                                 bigbuf = NULL;
                                         else
                                                 smallbuf = NULL;
-                                        smb_buffer = NULL;      /* will be freed by users thread after he is done */
+                                        smb_buffer = NULL; /* will be freed by users thread after he is done */
                                         wake_up_process(task_to_wake);
                                 } else if (is_valid_oplock_break(smb_buffer) == FALSE) {                          
                                         cERROR(1, ("No task to wake, unknown frame rcvd!"));
@@ -432,7 +442,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
         spin_unlock(&GlobalMid_Lock);
         /* Although there should not be any requests blocked on 
         this queue it can not hurt to be paranoid and try to wake up requests
-        that may haven been blocked when more than 50 at time were on the wire 
+        that may haven been blocked when more than 50 at time were on the wire
         to the same server - they now will see the session is in exit state
         and get out of SendReceive.  */
         wake_up_all(&server->request_q);
@@ -451,7 +461,8 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
 
         read_lock(&GlobalSMBSeslock);
         if (list_empty(&server->pending_mid_q)) {
-                /* loop through server session structures attached to this and mark them dead */
+                /* loop through server session structures attached to this and
+                    mark them dead */
                 list_for_each(tmp, &GlobalSMBSessionList) {
                         ses =
                             list_entry(tmp, struct cifsSesInfo,
@@ -468,7 +479,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                         if (mid_entry->midState == MID_REQUEST_SUBMITTED) {
                                 cFYI(1,
-                                         (" Clearing Mid 0x%x - waking up ",mid_entry->mid));
+                                  ("Clearing Mid 0x%x - waking up ",mid_entry->mid));
                                 task_to_wake = mid_entry->tsk;
                                 if(task_to_wake) {
                                         wake_up_process(task_to_wake);
@@ -521,7 +532,8 @@ cifs_parse_mount_options(char *options, const char *devname,struct smb_vol *vol)
                 /* does not have to be a perfect mapping since the field is
                 informational, only used for servers that do not support
                 port 445 and it can be overridden at mount time */
-                vol->source_rfc1001_name[i] = toupper(system_utsname.nodename[i]);
+                vol->source_rfc1001_name[i] = 
+                        toupper(system_utsname.nodename[i]);
         }
         vol->source_rfc1001_name[15] = 0;
 
@@ -596,14 +608,17 @@ cifs_parse_mount_options(char *options, const char *devname,struct smb_vol *vol)
                         /* NB: password legally can have multiple commas and
                         the only illegal character in a password is null */
 
-                        if ((value[temp_len] == 0) && (value[temp_len+1] == separator[0])) {
+                        if ((value[temp_len] == 0) && 
+                            (value[temp_len+1] == separator[0])) {
                                 /* reinsert comma */
                                 value[temp_len] = separator[0];
                                 temp_len+=2;  /* move after the second comma */
                                 while(value[temp_len] != 0)  {
                                         if (value[temp_len] == separator[0]) {
-                                                if (value[temp_len+1] == separator[0]) {
-                                                        temp_len++; /* skip second comma */
+                                                if (value[temp_len+1] == 
+                                                     separator[0]) {
+                                                /* skip second comma */
+                                                        temp_len++;
                                                 } else { 
                                                 /* single comma indicating start
                                                          of next parm */
@@ -629,14 +644,15 @@ cifs_parse_mount_options(char *options, const char *devname,struct smb_vol *vol)
                                 }
                                 for(i=0,j=0;i<temp_len;i++,j++) {
                                         vol->password[j] = value[i];
-                                        if(value[i] == separator[0] && value[i+1] == separator[0]) {
+                                        if(value[i] == separator[0]
+                                                && value[i+1] == separator[0]) {
                                                 /* skip second comma */
                                                 i++;
                                         }
                                 }
                                 vol->password[j] = 0;
                         } else {
-                                vol->password = kcalloc(1, temp_len + 1, GFP_KERNEL);
+                                vol->password = kcalloc(1, temp_len+1, GFP_KERNEL);
                                 if(vol->password == NULL) {
                                         printk("CIFS: no memory for pass\n");
                                         return 1;
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 39170cffcad8..22557716f9af 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -409,10 +409,15 @@ static char *nxt_dir_entry(char *old_entry, char *end_of_smb)
         cFYI(1,("new entry %p old entry %p",new_entry,old_entry));
         /* validate that new_entry is not past end of SMB */
         if(new_entry >= end_of_smb) {
-                cFYI(1,("search entry %p began after end of SMB %p old entry %p",
-                        new_entry,end_of_smb,old_entry)); 
+                cERROR(1,
+                      ("search entry %p began after end of SMB %p old entry %p",
+                        new_entry, end_of_smb, old_entry)); 
                 return NULL;
-        } else
+        } else if (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb) {
+                cERROR(1,("search entry %p extends after end of SMB %p",
+                        new_entry, end_of_smb));
+                return NULL;
+        } else 
                 return new_entry;
 
 }