Fixing stack smashing possibility for get_flags.

jsardo · Dec 5, 2017 · 93e54a9 · 93e54a9
1 parent da14019
commit 93e54a9
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Showing 4 changed files with 12 additions and 11 deletions.
diff --git a/arg_parse.c b/arg_parse.c
@@ -58,8 +58,9 @@ char **get_args(char *s, int index)
     return args;
 }
 
-char *get_flags(char *buf, char *flags)
+char *get_flags(char *buf)
 {
+    char* flags = (char *) malloc(BUFSIZE);
     while (*buf != '\0') {
         if (*buf == '-') {
             buf++;

diff --git a/arg_parse.h b/arg_parse.h
@@ -6,6 +6,6 @@
 int get_argc(char *s);
 char *skip_flag(char *s);
 char **get_args(char *s, int index);
-char *get_flags(char *buf, char *flags);
+char *get_flags(char *buf);
 
 #endif
diff --git a/cmd_mains.c b/cmd_mains.c
@@ -3,11 +3,11 @@
 
 int rm_main(char *buf)
 {
-    char **args, flags[5];
+    char **args, *flags;
     int pflag = 0, vflag = 0, rflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 2);
-    get_flags(buf, flags);
+    flags = get_flags(buf);
 
     if (flags[0] != '\0') {
         do {
@@ -51,11 +51,11 @@ int rm_main(char *buf)
 
 int ls_main(char *buf)
 {
-    char **args, flags[4];
+    char **args;
     int aflag = 0, iflag = 0, rflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 2);
-    get_flags(buf, flags);
+    flags = get_flags(buf);
 
     if (flags[0] != '\0') {
         do {
@@ -101,11 +101,11 @@ int ls_main(char *buf)
 
 int mkdir_main(char *buf)
 {
-    char **args, flags[5];
+    char **args;
     int vflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 5);
-    get_flags(buf, flags);
+    flags = get_flags(buf, flags);
 
    if (flags[0] != '\0') {
        do {
@@ -144,11 +144,11 @@ int mkdir_main(char *buf)
 
 int cat_main(char *buf)
 {
-    char **args, flags[5];
+    char **args;
     int nflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 3);
-    get_flags(buf, flags);
+    flags = get_flags(buf, flags);
 
     if (flags[0] != '\0') {
         do {

diff --git a/misc.h b/misc.h
@@ -29,7 +29,7 @@ void usage(void);
 int get_argc(char *s);
 char **get_args(char *s, int index);
 char *skip_flags(char *s);
-char *get_flags(char *buf, char *flags);
+char *get_flags(char *buf);
 bool prompt(char *fmt, ...);
 
 #endif