From fd63140e1c79369e6d1e90bf1849569e1477f4ec Mon Sep 17 00:00:00 2001
From: Nick Terrell <terrelln@fb.com>
Date: Fri, 5 Jan 2018 11:44:25 -0800
Subject: [PATCH 1/3] [util] Refuse to set file stat on non-regular file

---
 programs/util.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/programs/util.h b/programs/util.h
index af1fa7fc..4f22236a 100644
--- a/programs/util.h
+++ b/programs/util.h
@@ -246,11 +246,17 @@ UTIL_STATIC void UTIL_waitForNextTick(void)
 #endif
 
 
+UTIL_STATIC int UTIL_isRegularFile(const char* infilename);
+
+
 UTIL_STATIC int UTIL_setFileStat(const char *filename, stat_t *statbuf)
 {
     int res = 0;
     struct utimbuf timebuf;
 
+    if (!UTIL_isRegularFile(filename))
+        return -1;
+
     timebuf.actime = time(NULL);
     timebuf.modtime = statbuf->st_mtime;
     res += utime(filename, &timebuf);  /* set access and modification times */

From 282ad05e0a4214e429682062716ccd9ad5bafc23 Mon Sep 17 00:00:00 2001
From: Nick Terrell <terrelln@fb.com>
Date: Fri, 5 Jan 2018 11:44:45 -0800
Subject: [PATCH 2/3] [fileio] Use FIO_remove() everywhere for safety

---
 programs/fileio.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/programs/fileio.c b/programs/fileio.c
index f9c9087b..71b87d4d 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -139,7 +139,10 @@ static void INThandler(int sig)
 #if !defined(_MSC_VER)
     signal(sig, SIG_IGN);  /* this invocation generates a buggy warning in Visual Studio */
 #endif
-    if (g_artefact) remove(g_artefact);
+    if (g_artefact) {
+        assert(UTIL_isRegularFile(g_artefact));
+        remove(g_artefact);
+    }
     DISPLAY("\n");
     exit(2);
 }
@@ -861,7 +864,7 @@ static int FIO_compressFilename_srcFile(cRess_t ress,
          * delete both the source and destination files.
          */
         clearHandler();
-        if (remove(srcFileName))
+        if (FIO_remove(srcFileName))
             EXM_THROW(1, "zstd: %s: %s", srcFileName, strerror(errno));
     }
     return result;
@@ -899,10 +902,12 @@ static int FIO_compressFilename_dstFile(cRess_t ress,
         result=1;
     }
     if (result!=0) {  /* remove operation artefact */
-        if (remove(dstFileName))
+        if (FIO_remove(dstFileName))
             EXM_THROW(1, "zstd: %s: %s", dstFileName, strerror(errno));
     }
-    else if (strcmp (dstFileName, stdoutmark) && stat_result)
+    else if ( strcmp(dstFileName, stdoutmark)
+           && strcmp(dstFileName, nulmark)
+           && stat_result)
         UTIL_setFileStat(dstFileName, &statbuf);
 
     return result;
@@ -1575,7 +1580,7 @@ static int FIO_decompressSrcFile(dRess_t ress, const char* dstFileName, const ch
          * delete both the source and destination files.
          */
         clearHandler();
-        if (remove(srcFileName)) {
+        if (FIO_remove(srcFileName)) {
             /* failed to remove src file */
             DISPLAYLEVEL(1, "zstd: %s: %s \n", srcFileName, strerror(errno));
             return 1;
@@ -1618,7 +1623,7 @@ static int FIO_decompressDstFile(dRess_t ress,
     if ( (result != 0)  /* operation failure */
       && strcmp(dstFileName, nulmark)      /* special case : don't remove() /dev/null (#316) */
       && strcmp(dstFileName, stdoutmark) ) /* special case : don't remove() stdout */
-        remove(dstFileName);  /* remove decompression artefact; note don't do anything special if remove() fails */
+        FIO_remove(dstFileName);  /* remove decompression artefact; note don't do anything special if remove() fails */
     else {  /* operation success */
         if ( strcmp(dstFileName, stdoutmark) /* special case : don't chmod stdout */
           && strcmp(dstFileName, nulmark)    /* special case : don't chmod /dev/null */

From ed9611dc62bb1376012d229b0e6f7f974f5266db Mon Sep 17 00:00:00 2001
From: Nick Terrell <terrelln@fb.com>
Date: Fri, 5 Jan 2018 11:49:55 -0800
Subject: [PATCH 3/3] [fileio] Don't call FIO_remove() on stdout or /dev/null

---
 programs/fileio.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/programs/fileio.c b/programs/fileio.c
index 71b87d4d..887cbeb3 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -901,10 +901,10 @@ static int FIO_compressFilename_dstFile(cRess_t ress,
         DISPLAYLEVEL(1, "zstd: %s: %s \n", dstFileName, strerror(errno));
         result=1;
     }
-    if (result!=0) {  /* remove operation artefact */
-        if (FIO_remove(dstFileName))
-            EXM_THROW(1, "zstd: %s: %s", dstFileName, strerror(errno));
-    }
+    if ( (result != 0)  /* operation failure */
+      && strcmp(dstFileName, nulmark)      /* special case : don't remove() /dev/null */
+      && strcmp(dstFileName, stdoutmark) ) /* special case : don't remove() stdout */
+        FIO_remove(dstFileName); /* remove compression artefact; note don't do anything special if remove() fails */
     else if ( strcmp(dstFileName, stdoutmark)
            && strcmp(dstFileName, nulmark)
            && stat_result)