Fix problem with single quotes in args

Single quotes can't be represented in single quoted text, so quote them separately by double quotes.

1 files changed, 41 insertions, 4 deletions

diff --git a/src/firejail/main.c b/src/firejail/main.c
index 91f39ed71..28351a2df 100644
--- a/src/firejail/main.c
+++ b/src/firejail/main.c
@@ -2008,8 +2008,26 @@ int main(int argc, char **argv) {
                 int i;
                 int len = 0;
                 int argcnt = argc - prog_index;
-                for (i = 0; i < argcnt; i++)
-                        len += strlen(argv[i + prog_index]) + 3; // + ' ' + 2 '"'
+                int j;
+                char *arg, *arg_ptr, *token;
+
+                for (i = 0; i < argcnt; i++) {
+                        arg = strdup(argv[i + prog_index]);
+                        arg_ptr = arg;
+                        for (token = strsep(&arg_ptr, "\'"); token != NULL; token = strsep(&arg_ptr, "\'")) {
+                                if (token[0] == '\0') {
+                                        len += 3;
+                                } else {
+                                        len += strlen(token) + 5;
+                                }
+                        }
+                        free(arg);
+                        len -= 2; // + ' ' - 3 char overrun
+                }
+                len += 3; // for overrun
+
+                if (arg_debug)
+                        printf("Predicted command length %d\n", len);
 
                 // build the string
                 cfg.command_line = malloc(len + 1); // + '\0'
@@ -2022,12 +2040,31 @@ int main(int argc, char **argv) {
                 char *ptr1 = cfg.command_line;
                 char *ptr2 = cfg.window_title;
                 for (i = 0; i < argcnt; i++) {
-                        sprintf(ptr1, "\'%s\' ", argv[i + prog_index]);
-                        sprintf(ptr2, "%s ", argv[i + prog_index]);
+                        // enclose args by single quotes,
+                        // and since single quote can't be represented in single quoted text
+                        // each occurence of it in arg should be enclosed by double quotes
+                        arg = strdup(argv[i + prog_index]);
+                        arg_ptr = arg;
+                        for (token = strsep(&arg_ptr, "\'"); token != NULL; token = strsep(&arg_ptr, "\'")) {
+                                if (token[0] == '\0') {
+                                        sprintf(ptr1, "\"\'\"");
+                                } else {
+                                        sprintf(ptr1, "\'%s\'\"\'\"", token);
+                                }
+                                ptr1 += strlen(ptr1);
+                        }
+                        free(arg);
+                        ptr1 -= 3;
 
+                        sprintf(ptr1, " ");
                         ptr1 += strlen(ptr1);
+
+                        sprintf(ptr2, "%s ", argv[i + prog_index]);
                         ptr2 += strlen(ptr2);
                 }
+                ptr1[0]='\0'; // just to be sure
+                if (arg_debug)
+                        printf("Actual command length %zd\n", strlen(cfg.command_line));
         }
         
         assert(cfg.command_name);