From 39576639b2bdfa77e5e444587e3c615f651e9183 Mon Sep 17 00:00:00 2001
From: Marco Eichelberg <dicom@offis.de>
Date: Wed, 13 Mar 2024 17:15:58 +0100
Subject: Fixed two segmentation faults.
Bug-Debian: https://bugs.debian.org/1070207
Forwarded: not-needed

Fixed two segmentations faults that could occur while processing an
invalid incoming DIMSE message due to insufficient error handling
causing a de-referenced NULL pointer.

Thanks to Nils Bars <nils.bars@rub.de> for the bug report and sample files.

This closes DCMTK issue #1114.
---
 dcmdata/libsrc/dcelem.cc |  7 +++++++
 dcmnet/libsrc/dimcmd.cc  | 31 +++++++++++++++++--------------
 2 files changed, 24 insertions(+), 14 deletions(-)

--- a/dcmdata/libsrc/dcelem.cc
+++ b/dcmdata/libsrc/dcelem.cc
@@ -717,6 +717,13 @@
             if (isStreamNew)
                 delete readStream;
         }
+        else
+        {
+            errorFlag = EC_InvalidStream; // incomplete dataset read from stream
+            DCMDATA_ERROR("DcmElement: " << getTagName() << " " << getTag()
+                << " larger (" << getLengthField() << ") than remaining bytes ("
+                << getTransferredBytes() << ") in file, premature end of stream");
+        }
     }
     /* return result value */
     return errorFlag;
--- a/dcmnet/libsrc/dimcmd.cc
+++ b/dcmnet/libsrc/dimcmd.cc
@@ -207,22 +207,25 @@
             return parseErrorWithMsg("dimcmd:getString: string too small", t);
         } else {
             ec =  elem->getString(aString);
-            strncpy(s, aString, maxlen);
-            if (spacePadded)
+            if (ec.good())
             {
-                /* before we remove leading and tailing spaces we want to know
-                 * whether the string is actually space padded. Required to communicate
-                 * with dumb peers which send space padded UIDs and fail if they
-                 * receive correct UIDs back.
-                 *
-                 * This test can only detect space padded strings if
-                 * dcmEnableAutomaticInputDataCorrection is false; otherwise the padding
-                 * has already been removed by dcmdata at this stage.
-                 */
-                size_t s_len = strlen(s);
-                if ((s_len > 0)&&(s[s_len-1] == ' ')) *spacePadded = OFTrue; else *spacePadded = OFFalse;
+                strncpy(s, aString, maxlen);
+                if (spacePadded)
+                {
+                    /* before we remove leading and tailing spaces we want to know
+                     * whether the string is actually space padded. Required to communicate
+                     * with dumb peers which send space padded UIDs and fail if they
+                     * receive correct UIDs back.
+                     *
+                     * This test can only detect space padded strings if
+                     * dcmEnableAutomaticInputDataCorrection is false; otherwise the padding
+                     * has already been removed by dcmdata at this stage.
+                     */
+                    size_t s_len = strlen(s);
+                    if ((s_len > 0)&&(s[s_len-1] == ' ')) *spacePadded = OFTrue; else *spacePadded = OFFalse;
+                }
+                DU_stripLeadingAndTrailingSpaces(s);
             }
-            DU_stripLeadingAndTrailingSpaces(s);
         }
     }
     return (ec.good())? ec : DIMSE_PARSEFAILED;