Check return value of sigaction(), even though it should never fail.

diff --git a/src/exec.c b/src/exec.c
index a73950ab1068fefd065c9c483b2d9a1475467676..68b07ed5003b66d0465fbfddf81e3da51a3758a2 100644 (file)
--- a/src/exec.c
+++ b/src/exec.c
@@ -119,11 +119,13 @@ static int fork_cmnd(struct command_details *details, int sv[2])
 #else
     sa.sa_handler = handler;
 #endif
-    sudo_sigaction(SIGCONT, &sa, NULL);
+    if (sudo_sigaction(SIGCONT, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGCONT);
 #ifdef SA_SIGINFO
     sa.sa_sigaction = handler_user_only;
 #endif
-    sudo_sigaction(SIGTSTP, &sa, NULL);
+    if (sudo_sigaction(SIGTSTP, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTSTP);
 
     /*
      * The policy plugin's session init must be run before we fork
@@ -412,14 +414,21 @@ sudo_execute(struct command_details *details, struct command_status *cstat)
 #else
     sa.sa_handler = handler;
 #endif
-    sudo_sigaction(SIGTERM, &sa, NULL);
-    sudo_sigaction(SIGALRM, &sa, NULL); /* XXX - only if there is a timeout */
-    sudo_sigaction(SIGCHLD, &sa, NULL);
-    sudo_sigaction(SIGPIPE, &sa, NULL);
-    sudo_sigaction(SIGUSR1, &sa, NULL);
-    sudo_sigaction(SIGUSR2, &sa, NULL);
+    if (sudo_sigaction(SIGTERM, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTERM);
+    if (sudo_sigaction(SIGALRM, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGALRM);
+    if (sudo_sigaction(SIGCHLD, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGCHLD);
+    if (sudo_sigaction(SIGPIPE, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGPIPE);
+    if (sudo_sigaction(SIGUSR1, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGUSR1);
+    if (sudo_sigaction(SIGUSR2, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGUSR2);
 #ifdef SIGINFO
-    sudo_sigaction(SIGINFO, &sa, NULL);
+    if (sudo_sigaction(SIGINFO, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGINFO);
 #endif
 
     /*
@@ -435,9 +444,12 @@ sudo_execute(struct command_details *details, struct command_status *cstat)
        sa.sa_sigaction = handler_user_only;
     }
 #endif
-    sudo_sigaction(SIGHUP, &sa, NULL);
-    sudo_sigaction(SIGINT, &sa, NULL);
-    sudo_sigaction(SIGQUIT, &sa, NULL);
+    if (sudo_sigaction(SIGHUP, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGHUP);
+    if (sudo_sigaction(SIGINT, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGINT);
+    if (sudo_sigaction(SIGQUIT, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGQUIT);
 
     /*
      * Child will run the command in the pty, parent will pass data
@@ -584,12 +596,19 @@ dispatch_signal(struct sudo_event_base *evbase, pid_t child,
                    sigemptyset(&sa.sa_mask);
                    sa.sa_flags = SA_RESTART;
                    sa.sa_handler = SIG_DFL;
-                   sudo_sigaction(SIGTSTP, &sa, &osa);
+                   if (sudo_sigaction(SIGTSTP, &sa, &osa) != 0) {
+                       sudo_warn(U_("unable to set handler for signal %d"),
+                           SIGTSTP);
+                   }
                }
                if (kill(getpid(), signo) != 0)
                    sudo_warn("kill(%d, SIG%s)", (int)getpid(), signame);
-               if (signo == SIGTSTP)
-                   sudo_sigaction(SIGTSTP, &osa, NULL);
+               if (signo == SIGTSTP) {
+                   if (sudo_sigaction(SIGTSTP, &osa, NULL) != 0) {
+                       sudo_warn(U_("unable to restore handler for signal %d"),
+                           SIGTSTP);
+                   }
+               }
                if (fd != -1) {
                    /*
                     * Restore command's process group if different.
@@ -772,7 +791,8 @@ dispatch_pending_signals(struct command_status *cstat)
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;
        sa.sa_handler = SIG_DFL;
-       sudo_sigaction(SIGTSTP, &sa, NULL);
+       if (sudo_sigaction(SIGTSTP, &sa, NULL) != 0)
+           sudo_warn(U_("unable to set handler for signal %d"), SIGTSTP);
        if (kill(getpid(), SIGTSTP) != 0)
            sudo_warn("kill(%d, SIGTSTP)", (int)getpid());
        /* No need to reinstall SIGTSTP handler. */

diff --git a/src/exec_pty.c b/src/exec_pty.c
index cdebfb431a5c08c192f75e8997d3e544f6ab2e90..04cec866016884cd2f2b5652c9fb0bc1d64ab787 100644 (file)
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -456,7 +456,8 @@ suspend_parent(int signo)
            sigemptyset(&sa.sa_mask);
            sa.sa_flags = SA_RESTART;
            sa.sa_handler = SIG_DFL;
-           sudo_sigaction(signo, &sa, &osa);
+           if (sudo_sigaction(signo, &sa, &osa) != 0)
+               sudo_warn(U_("unable to set handler for signal %d"), signo);
        }
        sudo_debug_printf(SUDO_DEBUG_INFO, "kill parent SIG%s", signame);
        if (killpg(ppgrp, signo) != 0)
@@ -488,8 +489,10 @@ suspend_parent(int signo)
            ttymode = TERM_COOKED;
        }
 
-       if (signo != SIGSTOP)
-           sudo_sigaction(signo, &osa, NULL);
+       if (signo != SIGSTOP) {
+           if (sudo_sigaction(signo, &osa, NULL) != 0)
+               sudo_warn(U_("unable to restore handler for signal %d"), signo);
+       }
        rval = ttymode == TERM_RAW ? SIGCONT_FG : SIGCONT_BG;
        break;
     }
@@ -709,7 +712,8 @@ fork_pty(struct command_details *details, int sv[], sigset_t *omask)
     if (io_fds[SFD_USERTTY] != -1) {
        sa.sa_flags = SA_RESTART;
        sa.sa_handler = sigwinch;
-       sudo_sigaction(SIGWINCH, &sa, NULL);
+       if (sudo_sigaction(SIGWINCH, &sa, NULL) != 0)
+           sudo_warn(U_("unable to set handler for signal %d"), SIGWINCH);
     }
 
     /* So we can block tty-generated signals */
@@ -778,8 +782,10 @@ fork_pty(struct command_details *details, int sv[], sigset_t *omask)
 
     /* We don't want to receive SIGTTIN/SIGTTOU, getting EIO is preferable. */
     sa.sa_handler = SIG_IGN;
-    sudo_sigaction(SIGTTIN, &sa, NULL);
-    sudo_sigaction(SIGTTOU, &sa, NULL);
+    if (sudo_sigaction(SIGTTIN, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTTIN);
+    if (sudo_sigaction(SIGTTOU, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTTOU);
 
     /* Job control signals to relay from parent to child. */
     sigfillset(&sa.sa_mask);
@@ -790,7 +796,8 @@ fork_pty(struct command_details *details, int sv[], sigset_t *omask)
 #else
     sa.sa_handler = handler;
 #endif
-    sudo_sigaction(SIGTSTP, &sa, NULL);
+    if (sudo_sigaction(SIGTSTP, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTSTP);
 
     if (foreground) {
        /* Copy terminal attrs from user tty -> pty slave. */
@@ -1277,13 +1284,17 @@ exec_monitor(struct command_details *details, int backchannel)
     sigemptyset(&sa.sa_mask);
     sa.sa_flags = SA_RESTART;
     sa.sa_handler = SIG_DFL;
-    sudo_sigaction(SIGWINCH, &sa, NULL);
-    sudo_sigaction(SIGALRM, &sa, NULL);
+    if (sudo_sigaction(SIGWINCH, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGWINCH);
+    if (sudo_sigaction(SIGALRM, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGALRM);
 
     /* Ignore any SIGTTIN or SIGTTOU we get. */
     sa.sa_handler = SIG_IGN;
-    sudo_sigaction(SIGTTIN, &sa, NULL);
-    sudo_sigaction(SIGTTOU, &sa, NULL);
+    if (sudo_sigaction(SIGTTIN, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTTIN);
+    if (sudo_sigaction(SIGTTOU, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTTOU);
 
     /* Block all signals in mon_handler(). */
     sigfillset(&sa.sa_mask);
@@ -1296,7 +1307,8 @@ exec_monitor(struct command_details *details, int backchannel)
 #else
     sa.sa_handler = mon_handler;
 #endif
-    sudo_sigaction(SIGCHLD, &sa, NULL);
+    if (sudo_sigaction(SIGCHLD, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGCHLD);
 
     /* Catch common signals so we can cleanup properly. */
     sa.sa_flags = SA_RESTART;
@@ -1306,13 +1318,20 @@ exec_monitor(struct command_details *details, int backchannel)
 #else
     sa.sa_handler = mon_handler;
 #endif
-    sudo_sigaction(SIGHUP, &sa, NULL);
-    sudo_sigaction(SIGINT, &sa, NULL);
-    sudo_sigaction(SIGQUIT, &sa, NULL);
-    sudo_sigaction(SIGTERM, &sa, NULL);
-    sudo_sigaction(SIGTSTP, &sa, NULL);
-    sudo_sigaction(SIGUSR1, &sa, NULL);
-    sudo_sigaction(SIGUSR2, &sa, NULL);
+    if (sudo_sigaction(SIGHUP, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGHUP);
+    if (sudo_sigaction(SIGINT, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGINT);
+    if (sudo_sigaction(SIGQUIT, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGQUIT);
+    if (sudo_sigaction(SIGTERM, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTERM);
+    if (sudo_sigaction(SIGTSTP, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGTSTP);
+    if (sudo_sigaction(SIGUSR1, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGUSR1);
+    if (sudo_sigaction(SIGUSR2, &sa, NULL) != 0)
+       sudo_warn(U_("unable to set handler for signal %d"), SIGUSR2);
 
     /*
      * Start a new session with the parent as the session leader

diff --git a/src/signal.c b/src/signal.c
index 59b5cdb381d728c33037c739c0528e5b14d24afb..aa56a7e50a68851a4624751d10bb4b84a5312663 100644 (file)
--- a/src/signal.c
+++ b/src/signal.c
@@ -72,8 +72,10 @@ save_signals(void)
     struct signal_state *ss;
     debug_decl(save_signals, SUDO_DEBUG_MAIN)
 
-    for (ss = saved_signals; ss->signo != -1; ss++)
-       sigaction(ss->signo, NULL, &ss->sa);
+    for (ss = saved_signals; ss->signo != -1; ss++) {
+       if (sigaction(ss->signo, NULL, &ss->sa) != 0)
+           sudo_warn(U_("unable to save handler for signal %d"), ss->signo);
+    }
 
     debug_return;
 }
@@ -88,8 +90,12 @@ restore_signals(void)
     debug_decl(restore_signals, SUDO_DEBUG_MAIN)
 
     for (ss = saved_signals; ss->signo != -1; ss++) {
-       if (ss->restore)
-           sigaction(ss->signo, &ss->sa, NULL);
+       if (ss->restore) {
+           if (sigaction(ss->signo, &ss->sa, NULL) != 0) {
+               sudo_warn(U_("unable to restore handler for signal %d"),
+                   ss->signo);
+           }
+       }
     }
 
     debug_return;
@@ -145,8 +151,12 @@ init_signals(void)
                /* Don't install these until exec time. */
                break;
            default:
-               if (ss->sa.sa_handler != SIG_IGN)
-                   sigaction(ss->signo, &sa, NULL);
+               if (ss->sa.sa_handler != SIG_IGN) {
+                   if (sigaction(ss->signo, &sa, NULL) != 0) {
+                       sudo_warn(U_("unable to set handler for signal %d"),
+                           ss->signo);
+                   }
+               }
                break;
        }
     }