install: Fix chown resetting suid/sgid bits from chmod

Since Linux 2.2.13, chown(2) resets the suid/gid bits for all users.
This patch changes the ordering so that chmod gets called after chown.

This behavior follows GNU coreutils.

Signed-off-by: Nero <nero@w1r3.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/coreutils/install.c b/coreutils/install.c
index c0f1c538a..00f8be87e 100644
--- a/coreutils/install.c
+++ b/coreutils/install.c
@@ -244,6 +244,15 @@ int install_main(int argc, char **argv)
                         }
                 }
 
+                /* Set the user and group id */
+                /* (must be before chmod, or else chown may clear suid/gid bits) */
+                if ((opts & (OPT_OWNER|OPT_GROUP))
+                 && lchown(dest, uid, gid) == -1
+                ) {
+                        bb_perror_msg("can't change %s of %s", "ownership", dest);
+                        ret = EXIT_FAILURE;
+                }
+
                 /* Set the file mode (always, not only with -m).
                  * GNU coreutils 6.10 is not affected by umask. */
                 if (chmod(dest, mode) == -1) {
@@ -254,13 +263,6 @@ int install_main(int argc, char **argv)
                 if (use_default_selinux_context)
                         setdefaultfilecon(dest);
 #endif
-                /* Set the user and group id */
-                if ((opts & (OPT_OWNER|OPT_GROUP))
-                 && lchown(dest, uid, gid) == -1
-                ) {
-                        bb_perror_msg("can't change %s of %s", "ownership", dest);
-                        ret = EXIT_FAILURE;
-                }
  next:
                 if (ENABLE_FEATURE_CLEAN_UP && isdir)
                         free(dest);