Package: debianutils
Version: 5.20-0deepin1
Severity: normal
File: /usr/bin/ischroot
Tags: patch
X-Debbugs-Cc: wangzhao...@uniontech.com
Dear Maintainer,
I would like to report an issue with the ischroot utility from debianutils
where it incorrectly returns 0 when executed
inside an unshared mount namespace, which causes issues with hibernation and
wake-up functionality when generating initrd in an unshare environment.
Steps to Reproduce:
$ sudo unshare --mount bash
$ ischroot; echo $?
Observe that the exit code is 0, which indicates that ischroot incorrectly
detects the environment as a chroot.
Expected Behavior:
ischroot should return a non-zero value unless the process is actually inside a
chroot. Simply creating a new mount namespace using unshare does not constitute
a chroot environment.
-- System Information:
Distributor ID: Deepin
Description: Deepin 23
Release: 23
Codename: beige
Architecture: x86_64
Kernel: Linux 6.6.40-amd64-desktop-hwe (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=zh_CN.UTF-8, LC_CTYPE=zh_CN.UTF-8 (charmap=UTF-8), LANGUAGE=zh_CN
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages debianutils depends on:
ii libc6 2.38-6deepin7
debianutils recommends no packages.
debianutils suggests no packages.
-- no debconf information
diff --git a/ischroot.c b/ischroot.c
index 7318e7f..4fdc975 100644
--- a/ischroot.c
+++ b/ischroot.c
@@ -16,6 +16,7 @@
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
+#include <errno.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif /* HAVE_GETOPT_H */
@@ -135,13 +136,13 @@ static int ischroot()
struct stat st1, st2;
int ret;
- ret = ischroot_mountinfo();
- if (ret >= 0)
- return ret;
-
if (stat("/", &st1))
return 2;
if (stat("/proc/1/root", &st2)) {
+ /* If we get permission denied, try checking mountinfo instead,
+ * which can resolve mountinfo inconsistency issues in unshare
environments */
+ if (errno == EACCES)
+ goto check_mountinfo;
/* Does /proc/1/root exist at all? */
if (lstat("/proc/1/root" , &st2))
return 2;
@@ -154,6 +155,13 @@ static int ischroot()
return 1;
else
return 0;
+
+check_mountinfo:
+ ret = ischroot_mountinfo();
+ if (ret >= 0)
+ return ret;
+
+ return 0;
}
#elif defined (__FreeBSD_kernel__) || defined (__FreeBSD__)
