bugfix: unignore SIGPIPE before execing a user-controlled process

4 files changed, 17 insertions, 0 deletions

diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index a175f0a..bda8e52 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -268,6 +268,7 @@ static void trystart (void)
     char const *cargv[2] = { "run", 0 } ;
     PROG = "s6-supervise (child)" ;
     selfpipe_finish() ;
+    sig_restore(SIGPIPE) ;
     if (notifyp[0] >= 0) close(notifyp[0]) ;
     close(p[0]) ;
     if (notifyp[1] >= 0 && fd_move((int)fd, notifyp[1]) < 0)
@@ -391,6 +392,7 @@ static int uplastup_z (void)
     char fmt1[UINT_FMT] ;
     char *cargv[4] = { "finish", fmt0, fmt1, 0 } ;
     selfpipe_finish() ;
+    sig_restore(SIGPIPE) ;
     fmt0[uint_fmt(fmt0, WIFSIGNALED(status.wstat) ? 256 : WEXITSTATUS(status.wstat))] = 0 ;
     fmt1[uint_fmt(fmt1, WTERMSIG(status.wstat))] = 0 ;
     setsid() ;
diff --git a/src/supervision/s6-svlisten.c b/src/supervision/s6-svlisten.c
index 1364b44..1a25c54 100644
--- a/src/supervision/s6-svlisten.c
+++ b/src/supervision/s6-svlisten.c
@@ -1,10 +1,12 @@
 /* ISC license. */
 
 #include <stdint.h>
+#include <signal.h>
 
 #include <skalibs/sgetopt.h>
 #include <skalibs/types.h>
 #include <skalibs/bitarray.h>
+#include <skalibs/sig.h>
 #include <skalibs/tai.h>
 #include <skalibs/strerr2.h>
 #include <skalibs/djbunix.h>
@@ -69,8 +71,10 @@ int main (int argc, char const **argv, char const *const *envp)
     unsigned char upstate[bitarray_div8(argc1)] ;
     unsigned char readystate[bitarray_div8(argc1)] ;
     s6_svlisten_init(argc1, argv, &foo, ids, upstate, readystate, &deadline) ;
+    sig_restore(SIGPIPE) ;
     pid = child_spawn0(argv[argc1 + 1], argv + argc1 + 1, envp) ;
     if (!pid) strerr_diefu2sys(111, "spawn ", argv[argc1 + 1]) ;
+    if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ;
     if (wantrestart) s6_svlisten_loop(&foo, 0, 1, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
     e = s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
     if (e < 0) strerr_dief1x(102, "supervisor died") ;
diff --git a/src/supervision/s6-svlisten1.c b/src/supervision/s6-svlisten1.c
index eaad48c..b0d5dd8 100644
--- a/src/supervision/s6-svlisten1.c
+++ b/src/supervision/s6-svlisten1.c
@@ -1,11 +1,15 @@
 /* ISC license. */
 
 #include <stdint.h>
+#include <signal.h>
+
 #include <skalibs/sgetopt.h>
 #include <skalibs/types.h>
+#include <skalibs/sig.h>
 #include <skalibs/tai.h>
 #include <skalibs/strerr2.h>
 #include <skalibs/djbunix.h>
+
 #include "s6-svlisten.h"
 
 #define USAGE "s6-svlisten1 [ -U | -u | -d | -D | -r | -R ] [ -t timeout ] servicedir prog..."
@@ -49,8 +53,10 @@ int main (int argc, char const *const *argv, char const *const *envp)
   tain_add_g(&deadline, &tto) ;
   spfd = s6_svlisten_selfpipe_init() ;
   s6_svlisten_init(1, argv, &foo, &id, &upstate, &readystate, &deadline) ;
+  sig_restore(SIGPIPE) ;
   pid = child_spawn0(argv[1], argv + 1, envp) ;
   if (!pid) strerr_diefu2sys(111, "spawn ", argv[1]) ;
+  if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ;
   if (wantrestart) s6_svlisten_loop(&foo, 0, 1, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
   e = s6_svlisten_loop(&foo, wantup, wantready, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
   if (e < 0) strerr_dief1x(102, "supervisor died") ;
diff --git a/src/supervision/s6-svwait.c b/src/supervision/s6-svwait.c
index 2fc8fcb..87b9fde 100644
--- a/src/supervision/s6-svwait.c
+++ b/src/supervision/s6-svwait.c
@@ -1,11 +1,15 @@
 /* ISC license. */
 
 #include <stdint.h>
+#include <signal.h>
+
 #include <skalibs/sgetopt.h>
 #include <skalibs/types.h>
 #include <skalibs/bitarray.h>
+#include <skalibs/sig.h>
 #include <skalibs/tai.h>
 #include <skalibs/strerr2.h>
+
 #include "s6-svlisten.h"
 
 #define USAGE "s6-svwait [ -U | -u | -d | -D ] [ -a | -o ] [ -t timeout ] servicedir..."
@@ -50,6 +54,7 @@ int main (int argc, char const *const *argv)
     uint16_t ids[argc] ;
     unsigned char upstate[bitarray_div8(argc)] ;
     unsigned char readystate[bitarray_div8(argc)] ;
+    if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ;
     s6_svlisten_init(argc, argv, &foo, ids, upstate, readystate, &deadline) ;
     e = s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, -1, 0) ;
     if (e < 0) strerr_dief1x(102, "supervisor died") ;