From 0c4729516baa2fbefb0af66c38f434b1f7519078 Mon Sep 17 00:00:00 2001 From: Pádraig Brady Date: Sun, 18 May 2014 17:20:06 +0100 Subject: chroot: make changing root check more robust * src/chroot.c (is_root): A new helper function to determine if the passed argument is the root directory based on inode comparison. (main): Use the new helper rather than comparing strings. * tests/misc/chroot-fail.sh: Add cases for alternative root paths. --- src/chroot.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/chroot.c b/src/chroot.c index 0ded25dec..a623f883a 100644 --- a/src/chroot.c +++ b/src/chroot.c @@ -28,6 +28,7 @@ #include "ignore-value.h" #include "mgetgroups.h" #include "quote.h" +#include "root-dev-ino.h" #include "userspec.h" #include "xstrtol.h" @@ -158,6 +159,22 @@ parse_additional_groups (char const *groups, GETGROUPS_T **pgids, return ret; } +static bool +is_root (const char* dir) +{ + struct dev_ino root_ino; + if (! get_root_dev_ino (&root_ino)) + error (EXIT_CANCELED, errno, _("failed to get attributes of %s"), + quote ("/")); + + struct stat arg_st; + if (stat (dir, &arg_st) == -1) + error (EXIT_CANCELED, errno, _("failed to get attributes of %s"), + quote (dir)); + + return SAME_INODE (root_ino, arg_st); +} + void usage (int status) { @@ -253,7 +270,7 @@ main (int argc, char **argv) /* Only do chroot specific actions if actually changing root. The main difference here is that we don't change working dir. */ - if (! STREQ (argv[optind], "/")) + if (! is_root (argv[optind])) { /* We have to look up users and groups twice. - First, outside the chroot to load potentially necessary passwd/group -- cgit v1.2.3-70-g09d2