[PATCH 1/8] dialyzer: prevent buffer overflows

Michael Santos <>
Sat Oct 2 01:54:51 CEST 2010


Check length of buffers used with environment variables and debug
messages.
---
 erts/etc/common/Makefile.in |    2 +-
 erts/etc/common/dialyzer.c  |   10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/erts/etc/common/Makefile.in b/erts/etc/common/Makefile.in
index 9665566..333390b 100644
--- a/erts/etc/common/Makefile.in
+++ b/erts/etc/common/Makefile.in
@@ -333,7 +333,7 @@ $(OBJDIR)/erlc.o: erlc.c
 	$(CC) $(CFLAGS) -o $@ -c erlc.c
 
 $(BINDIR)/@: $(OBJDIR)/dialyzer.o
-	$(PURIFY) $(LD) $(LDFLAGS) -o $@ $(OBJDIR)/dialyzer.o -L$(OBJDIR) $(LIBS)
+	$(PURIFY) $(LD) $(LDFLAGS) -o $@ $(OBJDIR)/dialyzer.o -L$(OBJDIR) $(LIBS) $(ERTS_INTERNAL_LIBS)
 
 $(OBJDIR)/dialyzer.o: dialyzer.c
 	$(CC) $(CFLAGS) -o $@ -c dialyzer.c
diff --git a/erts/etc/common/dialyzer.c b/erts/etc/common/dialyzer.c
index 4b4c112..4453e63 100644
--- a/erts/etc/common/dialyzer.c
+++ b/erts/etc/common/dialyzer.c
@@ -147,6 +147,9 @@ main(int argc, char** argv)
     env = get_env("DIALYZER_EMULATOR");
     emulator = env ? env : get_default_emulator(argv[0]);
 
+    if (strlen(emulator) >= MAXPATHLEN)
+        error("Value of environment variable DIALYZER_EMULATOR is too large");
+
     /*
      * Allocate the argv vector to be used for arguments to Erlang.
      * Arrange for starting to pushing information in the middle of
@@ -228,7 +231,7 @@ main(int argc, char** argv)
 static void
 push_words(char* src)
 {
-    char sbuf[1024];
+    char sbuf[MAXPATHLEN];
     char* dst;
 
     dst = sbuf;
@@ -360,7 +363,7 @@ error(char* format, ...)
     va_list ap;
     
     va_start(ap, format);
-    vsprintf(sbuf, format, ap);
+    erts_vsnprintf(sbuf, sizeof(sbuf), format, ap);
     va_end(ap);
     fprintf(stderr, "dialyzer: %s\n", sbuf);
     exit(1);
@@ -389,6 +392,9 @@ get_default_emulator(char* progname)
     char sbuf[MAXPATHLEN];
     char* s;
 
+    if (strlen(progname) >= sizeof(sbuf))
+        return ERL_NAME;
+
     strcpy(sbuf, progname);
     for (s = sbuf+strlen(sbuf); s >= sbuf; s--) {
 	if (IS_DIRSEP(*s)) {
-- 
1.7.0.4



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