From a3549c2eecf12b3453e6c86ba1721e7837f23746 Mon Sep 17 00:00:00 2001 From: "Roberto E. Vargas Caballero" Date: Tue, 19 Aug 2014 00:55:02 +0200 Subject: [PATCH] Improve execsh() and don't allow anonymous shells This patch improves the shell selection on execsh and forbid shell with users don't registered in the passwd file. --- st.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/st.c b/st.c index 1c998ec..009388c 100644 --- a/st.c +++ b/st.c @@ -1139,23 +1139,29 @@ die(const char *errstr, ...) { void execsh(void) { - char **args; - char *envshell = getenv("SHELL"); - const struct passwd *pass = getpwuid(getuid()); + char **args, *sh; + const struct passwd *pw; char buf[sizeof(long) * 8 + 1]; + errno = 0; + if((pw = getpwuid(getuid())) == NULL) { + if(errno) + die("getpwuid:%s\n", strerror(errno)); + else + die("who are you?\n"); + } unsetenv("COLUMNS"); unsetenv("LINES"); unsetenv("TERMCAP"); - if(pass) { - setenv("LOGNAME", pass->pw_name, 1); - setenv("USER", pass->pw_name, 1); - setenv("SHELL", pass->pw_shell, 0); - setenv("HOME", pass->pw_dir, 0); - } - + sh = (pw->pw_shell[0]) ? pw->pw_shell : shell; snprintf(buf, sizeof(buf), "%lu", xw.win); + + setenv("LOGNAME", pw->pw_name, 1); + setenv("USER", pw->pw_name, 1); + setenv("SHELL", sh, 1); + setenv("HOME", pw->pw_dir, 1); + setenv("TERM", termname, 1); setenv("WINDOWID", buf, 1); signal(SIGCHLD, SIG_DFL); @@ -1165,9 +1171,7 @@ execsh(void) { signal(SIGTERM, SIG_DFL); signal(SIGALRM, SIG_DFL); - DEFAULT(envshell, shell); - setenv("TERM", termname, 1); - args = opt_cmd ? opt_cmd : (char *[]){envshell, "-i", NULL}; + args = opt_cmd ? opt_cmd : (char *[]){sh, "-i", NULL}; execvp(args[0], args); exit(EXIT_FAILURE); } -- 2.20.1