Escape control characters

Names and commands can contain control characters:

```
firejail --name="$(echo -e '\e[31mRed\n\b\b\bText\e[0m')" sleep 10s
```
results in "Text" printed in red.

Prevent commands like `--tree` to control the terminal.

2 files changed, 70 insertions, 1 deletions

diff --git a/src/lib/common.c b/src/lib/common.c
index 111366782..338e9316c 100644
--- a/src/lib/common.c
+++ b/src/lib/common.c
@@ -404,6 +404,61 @@ char *replace_cntrl_chars(const char *str, char c) {
         return rv;
 }
 
+char *escape_cntrl_chars(const char *str) {
+        if (str) {
+                unsigned int cntrl_chars = 0;
+                const char *c = str;
+                while (*c) {
+                        switch (*c++) {
+                                case '\b':
+                                case '\a':
+                                case '\e':
+                                case '\f':
+                                case '\n':
+                                case '\r':
+                                case '\t':
+                                case '\v':
+                                case '\"':
+                                case '\'':
+                                case '\?':
+                                case '\\':
+                                        ++cntrl_chars;
+                                default: break;
+                        }
+                }
+                char *rv = malloc(strlen(str) + cntrl_chars + 1);
+                char *ptr = rv;
+                if (!rv)
+                        errExit("malloc");
+                c = str;
+                while (*c) {
+                        if (iscntrl(*c)) {
+                                *ptr++ = '\\';
+                                switch (*c) {
+                                        case '\b': *ptr++ = 'b'; break;
+                                        case '\a': *ptr++ = 'a'; break;
+                                        case '\e': *ptr++ = 'e'; break;
+                                        case '\f': *ptr++ = 'f'; break;
+                                        case '\n': *ptr++ = 'n'; break;
+                                        case '\r': *ptr++ = 'r'; break;
+                                        case '\t': *ptr++ = 't'; break;
+                                        case '\v': *ptr++ = 'v'; break;
+                                        case '\"': *ptr++ = '\"'; break;
+                                        case '\'': *ptr++ = '\''; break;
+                                        case '\?': *ptr++ = '?'; break;
+                                        case '\\': *ptr++ = '\\'; break;
+                                }
+                        } else {
+                                *ptr++ = *c;
+                        }
+                        c++;
+                }
+                *ptr = '\0';
+                return rv;
+        }
+        return NULL;
+}
+
 int has_cntrl_chars(const char *str) {
         assert(str);
 
diff --git a/src/lib/pid.c b/src/lib/pid.c
index 5e9b20c94..cb9686648 100644
--- a/src/lib/pid.c
+++ b/src/lib/pid.c
@@ -197,6 +197,12 @@ static void print_elem(unsigned index, int nowrap) {
         char *user = pid_get_user_name(uid);
         char *user_allocated = user;
 
+        char *cmd_escape = escape_cntrl_chars(cmd);
+        if (cmd_escape) {
+                free(cmd);
+                cmd = cmd_escape;
+        }
+
         // extract sandbox name - pid == index
         char *sandbox_name = "";
         char *sandbox_name_allocated = NULL;
@@ -224,7 +230,15 @@ static void print_elem(unsigned index, int nowrap) {
         }
         free(fname);
 
-        if (user ==NULL)
+        char *sandbox_name_escape = escape_cntrl_chars(sandbox_name);
+        if (sandbox_name_escape) {
+                if (sandbox_name_allocated)
+                        free(sandbox_name_allocated);
+                sandbox_name = sandbox_name_escape;
+                sandbox_name_allocated = sandbox_name;
+        }
+
+        if (user == NULL)
                 user = "";
         if (cmd) {
                 if (col < 4 || nowrap)