run_no_sandbox fix

3 files changed, 110 insertions, 44 deletions

diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index 633935108..8301a79a0 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -283,6 +283,7 @@ char *guess_shell(void);
 
 // sandbox.c
 int sandbox(void* sandbox_arg);
+void start_application(void);
 
 // network_main.c
 void net_configure_bridge(Bridge *br, char *dev_name);
diff --git a/src/firejail/no_sandbox.c b/src/firejail/no_sandbox.c
index 80ed72dca..090c06761 100644
--- a/src/firejail/no_sandbox.c
+++ b/src/firejail/no_sandbox.c
@@ -162,54 +162,119 @@ int check_kernel_procs(void) {
 void run_no_sandbox(int argc, char **argv) {
         EUID_ASSERT();
 
-        // build command
-        char *command = NULL;
-        int allocated = 0;
-        if (argc == 1)
-                command = "/bin/bash";
-        else {
-                // calculate length
-                int len = 0;
-                int i;
-                for (i = 1; i < argc; i++) {
-                        if (i == 1 && strcmp(argv[i], "-c") == 0)
-                                continue;
-                        if (*argv[i] == '-')
-                                continue;
-                        break;
+        // process limited subset of options
+        int i;
+        for (i = 0; i < argc; i++) {
+                if (strcmp(argv[i], "--csh") == 0) {
+                        if (arg_shell_none) {
+                                fprintf(stderr, "Error: --shell=none was already specified.\n");
+                                exit(1);
+                        }
+                        if (cfg.shell) {
+                                fprintf(stderr, "Error: only one default user shell can be specified\n");
+                                exit(1);
+                        }
+                        cfg.shell = "/bin/csh";
                 }
-                int start_index = i;
-                for (i = start_index; i < argc; i++)
-                        len += strlen(argv[i]) + 3;
-                
-                // allocate
-                command = malloc(len + 1);
-                if (!command)
-                        errExit("malloc");
-                memset(command, 0, len + 1);
-                allocated = 1;
-                
-                // copy
-                for (i = start_index; i < argc; i++) {
-                        if (strchr(argv[i], '&')) {
-                                strcat(command, "\"");
-                                strcat(command, argv[i]);
-                                strcat(command, "\" ");
+                else if (strcmp(argv[i], "--zsh") == 0) {
+                        if (arg_shell_none) {
+                                fprintf(stderr, "Error: --shell=none was already specified.\n");
+                                exit(1);
+                        }
+                        if (cfg.shell) {
+                                fprintf(stderr, "Error: only one default user shell can be specified\n");
+                                exit(1);
+                        }
+                        cfg.shell = "/bin/zsh";
+                }
+                else if (strcmp(argv[i], "--shell=none") == 0) {
+                        arg_shell_none = 1;
+                        if (cfg.shell) {
+                                fprintf(stderr, "Error: a shell was already specified\n");
+                                exit(1);
+                        }
+                }
+                else if (strncmp(argv[i], "--shell=", 8) == 0) {
+                        if (arg_shell_none) {
+                                fprintf(stderr, "Error: --shell=none was already specified.\n");
+                                exit(1);
+                        }
+                        invalid_filename(argv[i] + 8);
+
+                        if (cfg.shell) {
+                                fprintf(stderr, "Error: only one user shell can be specified\n");
+                                exit(1);
+                        }
+                        cfg.shell = argv[i] + 8;
+
+                        if (is_dir(cfg.shell) || strstr(cfg.shell, "..")) {
+                                fprintf(stderr, "Error: invalid shell\n");
+                                exit(1);
                         }
-                        else {
-                                strcat(command, argv[i]);
-                                strcat(command, " ");
+
+                        // access call checks as real UID/GID, not as effective UID/GID
+                        if(cfg.chrootdir) {
+                                char *shellpath;
+                                if (asprintf(&shellpath, "%s%s", cfg.chrootdir, cfg.shell) == -1)
+                                        errExit("asprintf");
+                                if (access(shellpath, R_OK)) {
+                                        fprintf(stderr, "Error: cannot access shell file in chroot\n");
+                                        exit(1);
+                                }
+                                free(shellpath);
+                        } else if (access(cfg.shell, R_OK)) {
+                                fprintf(stderr, "Error: cannot access shell file\n");
+                                exit(1);
                         }
                 }
         }
-        
-        // start the program in /bin/sh
+
+        // use $SHELL to get shell used in sandbox
+        if (!arg_shell_none && !cfg.shell) {
+                char *shell =  secure_getenv("SHELL");
+                if (access(shell, R_OK) == 0)
+                        cfg.shell = shell;
+        }
+        // guess shell otherwise
+        if (!arg_shell_none && !cfg.shell) {
+                guess_shell();
+                if (arg_debug)
+                        printf("Autoselecting %s as shell\n", cfg.shell);
+        }
+        if (!arg_shell_none && !cfg.shell) {
+                fprintf(stderr, "Error: unable to guess your shell, please set explicitly by using --shell option.\n");
+                exit(1);
+        }
+
+        int prog_index = 0;
+        // find first non option arg
+        for (i = 1; i < argc; i++) {
+                if (strncmp(argv[i],"--",2) != 0) {
+                        prog_index = i;
+                        break;
+                }
+        }
+
+        if (!arg_shell_none) {
+                if (prog_index == 0) {
+                        cfg.command_line = cfg.shell;
+                        cfg.window_title = cfg.shell;
+                } else {
+                        build_cmdline(&cfg.command_line, &cfg.window_title, argc, argv, prog_index);
+                }
+        }
+
+        cfg.original_argv = argv;
+        cfg.original_program_index = prog_index;
+
+        char *command;
+        if (prog_index == 0)
+                command = cfg.shell;
+        else
+                command = argv[prog_index];
         if (!arg_quiet)
                 fprintf(stderr, "Warning: an existing sandbox was detected. "
-                        "%s will run without any additional sandboxing features in a /bin/sh shell\n", command);
-        int rv = system(command);
-        (void) rv;
-        if (allocated)
-                free(command);
-        exit(1);
+                        "%s will run without any additional sandboxing features\n", command);
+
+        start_application();
 }
diff --git a/src/firejail/sandbox.c b/src/firejail/sandbox.c
index 8178cfc8e..c40ff1d03 100644
--- a/src/firejail/sandbox.c
+++ b/src/firejail/sandbox.c
@@ -284,7 +284,7 @@ void start_audit(void) {
         exit(1);
 }
 
-static void start_application(void) {
+void start_application(void) {
         //****************************************
         // audit
         //****************************************