From 03bf37877f1c7045724cba12d69e93c8c411646e Mon Sep 17 00:00:00 2001

From: Anita Zhang <the.anitazha@gmail.com>

Date: Wed, 26 Jan 2022 10:53:40 -0800

Subject: [PATCH] tree-wide: don't use strjoina() on getenv() values

Avoid doing stack allocations on environment variables.

(cherry picked from commit 1d3b68f6e1538b6a86cbe3650d8b81df2877ef42)

Related: #2017035

---

 src/basic/path-lookup.c  |  8 ++++++--

 src/core/dbus.c          |  8 ++++++--

 src/home/homed-home.c    | 10 +++++++---

 src/home/homed-manager.c | 26 ++++++++++++++++++--------

 src/run/run.c            |  7 +++++--

 src/shared/pager.c       |  9 +++++++--

 6 files changed, 49 insertions(+), 19 deletions(-)

diff --git a/src/basic/path-lookup.c b/src/basic/path-lookup.c

index 6fb8c40e7a..921a30cef7 100644

--- a/src/basic/path-lookup.c

+++ b/src/basic/path-lookup.c

@@ -238,7 +238,7 @@ static int acquire_generator_dirs(

                 char **generator_early,

                 char **generator_late) {

-        _cleanup_free_ char *x = NULL, *y = NULL, *z = NULL;

+        _cleanup_free_ char *x = NULL, *y = NULL, *z = NULL, *p = NULL;

         const char *prefix;

         assert(generator);

@@ -261,7 +261,11 @@ static int acquire_generator_dirs(

                 if (!e)

                         return -ENXIO;

-                prefix = strjoina(e, "/systemd");

+                p = path_join(e, "/systemd");

+                if (!p)

+                        return -ENOMEM;

+

+                prefix = p;

         }

         x = path_join(prefix, "generator");

diff --git a/src/core/dbus.c b/src/core/dbus.c

index 2c5bda58f9..073675ceef 100644

--- a/src/core/dbus.c

+++ b/src/core/dbus.c

@@ -925,14 +925,18 @@ int bus_init_private(Manager *m) {

                 r = sockaddr_un_set_path(&sa.un, "/run/systemd/private");

         } else {

-                const char *e, *joined;

+                _cleanup_free_ char *joined = NULL;

+                const char *e;

                 e = secure_getenv("XDG_RUNTIME_DIR");

                 if (!e)

                         return log_error_errno(SYNTHETIC_ERRNO(EHOSTDOWN),

                                                "XDG_RUNTIME_DIR is not set, refusing.");

-                joined = strjoina(e, "/systemd/private");

+                joined = path_join(e, "/systemd/private");

+                if (!joined)

+                        return log_oom();

+

                 r = sockaddr_un_set_path(&sa.un, joined);

         }

         if (r < 0)

diff --git a/src/home/homed-home.c b/src/home/homed-home.c

index 470c7f07f6..1340cf30d3 100644

--- a/src/home/homed-home.c

+++ b/src/home/homed-home.c

@@ -1185,14 +1185,18 @@ static int home_start_work(Home *h, const char *verb, UserRecord *hr, UserRecord

         if (r < 0)

                 return r;

         if (r == 0) {

+                _cleanup_free_ char *joined = NULL;

                 const char *homework, *suffix, *unix_path;

                 /* Child */

                 suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX");

-                if (suffix)

-                        unix_path = strjoina("/run/systemd/home/notify.", suffix);

-                else

+                if (suffix) {

+                        joined = strjoin("/run/systemd/home/notify.", suffix);

+                        if (!joined)

+                                return log_oom();

+                        unix_path = joined;

+                } else

                         unix_path = "/run/systemd/home/notify";

                 if (setenv("NOTIFY_SOCKET", unix_path, 1) < 0) {

diff --git a/src/home/homed-manager.c b/src/home/homed-manager.c

index 6c178b8a0e..c1ec555cac 100644

--- a/src/home/homed-manager.c

+++ b/src/home/homed-manager.c

@@ -936,6 +936,7 @@ int manager_enumerate_images(Manager *m) {

 }

 static int manager_connect_bus(Manager *m) {

+        _cleanup_free_ char *b = NULL;

         const char *suffix, *busname;

         int r;

@@ -955,9 +956,12 @@ static int manager_connect_bus(Manager *m) {

                 return r;

         suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX");

-        if (suffix)

-                busname = strjoina("org.freedesktop.home1.", suffix);

-        else

+        if (suffix) {

+                b = strjoin("org.freedesktop.home1.", suffix);

+                if (!b)

+                        return log_oom();

+                busname = b;

+        } else

                 busname = "org.freedesktop.home1";

         r = sd_bus_request_name_async(m->bus, NULL, busname, 0, NULL, NULL);

@@ -974,6 +978,7 @@ static int manager_connect_bus(Manager *m) {

 }

 static int manager_bind_varlink(Manager *m) {

+        _cleanup_free_ char *p = NULL;

         const char *suffix, *socket_path;

         int r;

@@ -999,9 +1004,12 @@ static int manager_bind_varlink(Manager *m) {

         /* To make things easier to debug, when working from a homed managed home directory, let's optionally

          * use a different varlink socket name */

         suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX");

-        if (suffix)

-                socket_path = strjoina("/run/systemd/userdb/io.systemd.Home.", suffix);

-        else

+        if (suffix) {

+                p = strjoin("/run/systemd/userdb/io.systemd.Home.", suffix);

+                if (!p)

+                        return log_oom();

+                socket_path = p;

+        } else

                 socket_path = "/run/systemd/userdb/io.systemd.Home";

         r = varlink_server_listen_address(m->varlink_server, socket_path, 0666);

@@ -1159,9 +1167,11 @@ static int manager_listen_notify(Manager *m) {

         suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX");

         if (suffix) {

-                const char *unix_path;

+                _cleanup_free_ char *unix_path = NULL;

-                unix_path = strjoina("/run/systemd/home/notify.", suffix);

+                unix_path = strjoin("/run/systemd/home/notify.", suffix);

+                if (!unix_path)

+                        return log_oom();

                 r = sockaddr_un_set_path(&sa.un, unix_path);

                 if (r < 0)

                         return log_error_errno(r, "Socket path %s does not fit in sockaddr_un: %m", unix_path);

diff --git a/src/run/run.c b/src/run/run.c

index ff24373847..e75b027542 100644

--- a/src/run/run.c

+++ b/src/run/run.c

@@ -794,9 +794,12 @@ static int transient_service_set_properties(sd_bus_message *m, const char *pty_p

                 e = getenv("TERM");

                 if (e) {

-                        char *n;

+                        _cleanup_free_ char *n = NULL;

+

+                        n = strjoin("TERM=", e);

+                        if (!n)

+                                return log_oom();

-                        n = strjoina("TERM=", e);

                         r = sd_bus_message_append(m,

                                                   "(sv)",

                                                   "Environment", "as", 1, n);

diff --git a/src/shared/pager.c b/src/shared/pager.c

index f75ef62d2d..9426d3ef98 100644

--- a/src/shared/pager.c

+++ b/src/shared/pager.c

@@ -86,6 +86,7 @@ static int no_quit_on_interrupt(int exe_name_fd, const char *less_opts) {

 void pager_open(PagerFlags flags) {

         _cleanup_close_pair_ int fd[2] = { -1, -1 }, exe_name_pipe[2] = { -1, -1 };

         _cleanup_strv_free_ char **pager_args = NULL;

+        _cleanup_free_ char *l = NULL;

         const char *pager, *less_opts;

         int r;

@@ -131,8 +132,12 @@ void pager_open(PagerFlags flags) {

         less_opts = getenv("SYSTEMD_LESS");

         if (!less_opts)

                 less_opts = "FRSXMK";

-        if (flags & PAGER_JUMP_TO_END)

-                less_opts = strjoina(less_opts, " +G");

+        if (flags & PAGER_JUMP_TO_END) {

+                l = strjoin(less_opts, " +G");

+                if (!l)

+                        return (void) log_oom();

+                less_opts = l;

+        }

         /* We set SIGINT as PR_DEATHSIG signal here, to match the "K" parameter we set in $LESS, which enables SIGINT behaviour. */

         r = safe_fork("(pager)", FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGINT|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pager_pid);