upstream commit

move subprocess() so scp/sftp do not need uidswap.o; ok
djm@

OpenBSD-Commit-ID: 6601b8360388542c2e5fef0f4085f8e54750bea8

diff --git a/auth.c b/auth.c
index a449061741afc1c47e0fb274f307ca23668d7e5a..fd02eff072d8ec8b8e217da33fd3114c959a2c50 100644 (file)
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.124 2017/09/12 06:32:07 djm Exp $ */
+/* $OpenBSD: auth.c,v 1.125 2018/01/08 15:21:49 markus Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -28,6 +28,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 
 #include <netinet/in.h>
 
@@ -840,3 +841,155 @@ auth_get_canonical_hostname(struct ssh *ssh, int use_dns)
                return dnsname;
        }
 }
+
+/*
+ * Runs command in a subprocess wuth a minimal environment.
+ * Returns pid on success, 0 on failure.
+ * The child stdout and stderr maybe captured, left attached or sent to
+ * /dev/null depending on the contents of flags.
+ * "tag" is prepended to log messages.
+ * NB. "command" is only used for logging; the actual command executed is
+ * av[0].
+ */
+pid_t
+subprocess(const char *tag, struct passwd *pw, const char *command,
+    int ac, char **av, FILE **child, u_int flags)
+{
+       FILE *f = NULL;
+       struct stat st;
+       int fd, devnull, p[2], i;
+       pid_t pid;
+       char *cp, errmsg[512];
+       u_int envsize;
+       char **child_env;
+
+       if (child != NULL)
+               *child = NULL;
+
+       debug3("%s: %s command \"%s\" running as %s (flags 0x%x)", __func__,
+           tag, command, pw->pw_name, flags);
+
+       /* Check consistency */
+       if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
+           (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) {
+               error("%s: inconsistent flags", __func__);
+               return 0;
+       }
+       if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) {
+               error("%s: inconsistent flags/output", __func__);
+               return 0;
+       }
+
+       /*
+        * If executing an explicit binary, then verify the it exists
+        * and appears safe-ish to execute
+        */
+       if (*av[0] != '/') {
+               error("%s path is not absolute", tag);
+               return 0;
+       }
+       temporarily_use_uid(pw);
+       if (stat(av[0], &st) < 0) {
+               error("Could not stat %s \"%s\": %s", tag,
+                   av[0], strerror(errno));
+               restore_uid();
+               return 0;
+       }
+       if (safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) {
+               error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
+               restore_uid();
+               return 0;
+       }
+       /* Prepare to keep the child's stdout if requested */
+       if (pipe(p) != 0) {
+               error("%s: pipe: %s", tag, strerror(errno));
+               restore_uid();
+               return 0;
+       }
+       restore_uid();
+
+       switch ((pid = fork())) {
+       case -1: /* error */
+               error("%s: fork: %s", tag, strerror(errno));
+               close(p[0]);
+               close(p[1]);
+               return 0;
+       case 0: /* child */
+               /* Prepare a minimal environment for the child. */
+               envsize = 5;
+               child_env = xcalloc(sizeof(*child_env), envsize);
+               child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH);
+               child_set_env(&child_env, &envsize, "USER", pw->pw_name);
+               child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name);
+               child_set_env(&child_env, &envsize, "HOME", pw->pw_dir);
+               if ((cp = getenv("LANG")) != NULL)
+                       child_set_env(&child_env, &envsize, "LANG", cp);
+
+               for (i = 0; i < NSIG; i++)
+                       signal(i, SIG_DFL);
+
+               if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
+                       error("%s: open %s: %s", tag, _PATH_DEVNULL,
+                           strerror(errno));
+                       _exit(1);
+               }
+               if (dup2(devnull, STDIN_FILENO) == -1) {
+                       error("%s: dup2: %s", tag, strerror(errno));
+                       _exit(1);
+               }
+
+               /* Set up stdout as requested; leave stderr in place for now. */
+               fd = -1;
+               if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0)
+                       fd = p[1];
+               else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0)
+                       fd = devnull;
+               if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) {
+                       error("%s: dup2: %s", tag, strerror(errno));
+                       _exit(1);
+               }
+               closefrom(STDERR_FILENO + 1);
+
+               /* Don't use permanently_set_uid() here to avoid fatal() */
+               if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
+                       error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
+                           strerror(errno));
+                       _exit(1);
+               }
+               if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
+                       error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
+                           strerror(errno));
+                       _exit(1);
+               }
+               /* stdin is pointed to /dev/null at this point */
+               if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
+                   dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
+                       error("%s: dup2: %s", tag, strerror(errno));
+                       _exit(1);
+               }
+
+               execve(av[0], av, child_env);
+               error("%s exec \"%s\": %s", tag, command, strerror(errno));
+               _exit(127);
+       default: /* parent */
+               break;
+       }
+
+       close(p[1]);
+       if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0)
+               close(p[0]);
+       else if ((f = fdopen(p[0], "r")) == NULL) {
+               error("%s: fdopen: %s", tag, strerror(errno));
+               close(p[0]);
+               /* Don't leave zombie child */
+               kill(pid, SIGTERM);
+               while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
+                       ;
+               return 0;
+       }
+       /* Success */
+       debug3("%s: %s pid %ld", __func__, tag, (long)pid);
+       if (child != NULL)
+               *child = f;
+       return pid;
+}

diff --git a/auth.h b/auth.h
index 29835ae92750f59c52646bac5f7be4eef0b84385..64f3c2eb5ec6abade8f0e2428d72d91f58a33d71 100644 (file)
--- a/auth.h
+++ b/auth.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.h,v 1.93 2017/08/18 05:36:45 djm Exp $ */
+/* $OpenBSD: auth.h,v 1.94 2018/01/08 15:21:49 markus Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -221,6 +221,12 @@ void        auth_debug_reset(void);
 
 struct passwd *fakepw(void);
 
+#define        SSH_SUBPROCESS_STDOUT_DISCARD  (1)     /* Discard stdout */
+#define        SSH_SUBPROCESS_STDOUT_CAPTURE  (1<<1)  /* Redirect stdout */
+#define        SSH_SUBPROCESS_STDERR_DISCARD  (1<<2)  /* Discard stderr */
+pid_t  subprocess(const char *, struct passwd *,
+    const char *, int, char **, FILE **, u_int flags);
+
 int     sys_auth_passwd(Authctxt *, const char *);
 
 #define SKEY_PROMPT "\nS/Key Password: "

diff --git a/misc.c b/misc.c
index 50988cefe9bfcd0ccc74e712cb65f4c429bc6cf5..f6fbb5e4a29593a42537b222e92ed104ae2e5b5c 100644 (file)
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.122 2017/12/08 02:14:33 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.123 2018/01/08 15:21:49 markus Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1740,158 +1740,6 @@ argv_assemble(int argc, char **argv)
        return ret;
 }
 
-/*
- * Runs command in a subprocess wuth a minimal environment.
- * Returns pid on success, 0 on failure.
- * The child stdout and stderr maybe captured, left attached or sent to
- * /dev/null depending on the contents of flags.
- * "tag" is prepended to log messages.
- * NB. "command" is only used for logging; the actual command executed is
- * av[0].
- */
-pid_t
-subprocess(const char *tag, struct passwd *pw, const char *command,
-    int ac, char **av, FILE **child, u_int flags)
-{
-       FILE *f = NULL;
-       struct stat st;
-       int fd, devnull, p[2], i;
-       pid_t pid;
-       char *cp, errmsg[512];
-       u_int envsize;
-       char **child_env;
-
-       if (child != NULL)
-               *child = NULL;
-
-       debug3("%s: %s command \"%s\" running as %s (flags 0x%x)", __func__,
-           tag, command, pw->pw_name, flags);
-
-       /* Check consistency */
-       if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
-           (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) {
-               error("%s: inconsistent flags", __func__);
-               return 0;
-       }
-       if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) {
-               error("%s: inconsistent flags/output", __func__);
-               return 0;
-       }
-
-       /*
-        * If executing an explicit binary, then verify the it exists
-        * and appears safe-ish to execute
-        */
-       if (*av[0] != '/') {
-               error("%s path is not absolute", tag);
-               return 0;
-       }
-       temporarily_use_uid(pw);
-       if (stat(av[0], &st) < 0) {
-               error("Could not stat %s \"%s\": %s", tag,
-                   av[0], strerror(errno));
-               restore_uid();
-               return 0;
-       }
-       if (safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) {
-               error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
-               restore_uid();
-               return 0;
-       }
-       /* Prepare to keep the child's stdout if requested */
-       if (pipe(p) != 0) {
-               error("%s: pipe: %s", tag, strerror(errno));
-               restore_uid();
-               return 0;
-       }
-       restore_uid();
-
-       switch ((pid = fork())) {
-       case -1: /* error */
-               error("%s: fork: %s", tag, strerror(errno));
-               close(p[0]);
-               close(p[1]);
-               return 0;
-       case 0: /* child */
-               /* Prepare a minimal environment for the child. */
-               envsize = 5;
-               child_env = xcalloc(sizeof(*child_env), envsize);
-               child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH);
-               child_set_env(&child_env, &envsize, "USER", pw->pw_name);
-               child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name);
-               child_set_env(&child_env, &envsize, "HOME", pw->pw_dir);
-               if ((cp = getenv("LANG")) != NULL)
-                       child_set_env(&child_env, &envsize, "LANG", cp);
-
-               for (i = 0; i < NSIG; i++)
-                       signal(i, SIG_DFL);
-
-               if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
-                       error("%s: open %s: %s", tag, _PATH_DEVNULL,
-                           strerror(errno));
-                       _exit(1);
-               }
-               if (dup2(devnull, STDIN_FILENO) == -1) {
-                       error("%s: dup2: %s", tag, strerror(errno));
-                       _exit(1);
-               }
-
-               /* Set up stdout as requested; leave stderr in place for now. */
-               fd = -1;
-               if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0)
-                       fd = p[1];
-               else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0)
-                       fd = devnull;
-               if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) {
-                       error("%s: dup2: %s", tag, strerror(errno));
-                       _exit(1);
-               }
-               closefrom(STDERR_FILENO + 1);
-
-               /* Don't use permanently_set_uid() here to avoid fatal() */
-               if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
-                       error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
-                           strerror(errno));
-                       _exit(1);
-               }
-               if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
-                       error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
-                           strerror(errno));
-                       _exit(1);
-               }
-               /* stdin is pointed to /dev/null at this point */
-               if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
-                   dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
-                       error("%s: dup2: %s", tag, strerror(errno));
-                       _exit(1);
-               }
-
-               execve(av[0], av, child_env);
-               error("%s exec \"%s\": %s", tag, command, strerror(errno));
-               _exit(127);
-       default: /* parent */
-               break;
-       }
-
-       close(p[1]);
-       if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0)
-               close(p[0]);
-       else if ((f = fdopen(p[0], "r")) == NULL) {
-               error("%s: fdopen: %s", tag, strerror(errno));
-               close(p[0]);
-               /* Don't leave zombie child */
-               kill(pid, SIGTERM);
-               while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
-                       ;
-               return 0;
-       }
-       /* Success */
-       debug3("%s: %s pid %ld", __func__, tag, (long)pid);
-       if (child != NULL)
-               *child = f;
-       return pid;
-}
-
 /* Returns 0 if pid exited cleanly, non-zero otherwise */
 int
 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)

diff --git a/misc.h b/misc.h
index e8e6a18d1f6d9dcb6112f6db6e3e2fe174237e92..8f7780675f5233f3196cfbcdc3c4191ea296a1e7 100644 (file)
--- a/misc.h
+++ b/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.69 2017/12/05 23:59:47 dtucker Exp $ */
+/* $OpenBSD: misc.h,v 1.70 2018/01/08 15:21:49 markus Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -149,12 +149,6 @@ int         argv_split(const char *, int *, char ***);
 char   *argv_assemble(int, char **argv);
 int     exited_cleanly(pid_t, const char *, const char *, int);
 
-#define SSH_SUBPROCESS_STDOUT_DISCARD  (1)     /* Discard stdout */
-#define SSH_SUBPROCESS_STDOUT_CAPTURE  (1<<1)  /* Redirect stdout */
-#define SSH_SUBPROCESS_STDERR_DISCARD  (1<<2)  /* Discard stderr */
-pid_t   subprocess(const char *, struct passwd *,
-    const char *, int, char **, FILE **, u_int flags);
-
 struct stat;
 int     safe_path(const char *, struct stat *, const char *, uid_t,
             char *, size_t);