Bug 1385272

Summary:	rhel-autorelabel service corrupts filesystem
Product:	Red Hat Enterprise Linux 7	Reporter:	Enrico Scholz <rh-bugzilla>
Component:	initscripts	Assignee:	David Kaspar // Dee'Kej <deekej>
Status:	CLOSED ERRATA	QA Contact:	Leos Pol <lpol>
Severity:	high	Docs Contact:	Filip Hanzelka <fhanzelk>
Priority:	urgent
Version:	7.2	CC:	deekej, pasik, rjones
Target Milestone:	rc	Keywords:	Patch
Target Release:	---
Hardware:	x86_64
OS:	Unspecified
Whiteboard:
Fixed In Version:	initscripts-9.49.39-1.el7	Doc Type:	Release Note
Doc Text:	rhel-autorelabel no longer corrupts the filesystem In previous versions of Red Hat Enterprise Linux 7, forcing the SELinux autorelabel by creating the `/.autorelabel` file sometimes partially corrupted the filesystem. This made the system unbootable. A patch has been applied to prevent this behaviour. As a result, applying the autorelabel operation using the "touch /.autorelabel" command is no more expected to corrupt the filesystem.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-01 07:29:01 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1380361, 1393867, 1400961

Description Enrico Scholz 2016-10-15 20:40:44 UTC

Description of problem:

Forcing an autorelabel operation (touch /.autorelabel) can break the system:

* boot loops; recovery only by booting into init 1 level and removing /.autorelabel manually

* various files (all SELinux .pp modules) are zeroed


This might be a bug in systemctl's "reboot" command which shutdowns the system in an unclean way although only a single "--force" has been given.


E.g. in the file /lib/systemd/rhel-autorelabel there is executed:

|    rm -f  /.autorelabel
|    /usr/lib/dracut/dracut-initramfs-restore
|    systemctl --force reboot

I did a

| ls -l /etc/selinux/targeted/modules/active/base.pp

at the beginning of the file and immediately before the 'systemctl reboot'.  On a fresh system where autorelabel has been forced, both 'ls' showed 'base.pp' with a correct size.

System rebooted, jumped into the autorelabel service again and 'ls' showed 'base.pp' with a size of '0'.

Putting a 'sync' before 'systemctl' seems to solve the problem.


Kernel cmdline is

| BOOT_IMAGE=/vmlinuz-3.10.0-327.36.2.el7.x86_64 root=/dev/mapper/vg00-root ro panic=180 crashkernel=auto rd.lvm.lv=vg00/root rd.lvm.lv=vg01/swap console=ttyS0 LANG=en_US.UTF-8


*NOTE*  / is on an LVM volume;  system is an KVM guests


Version-Release number of selected component (if applicable):

initscripts-9.49.30-1.el7_2.3.x86_64
systemd-219-19.el7_2.13.x86_64
selinux-policy-3.13.1-60.el7_2.9.noarch



How reproducible:

100%


Steps to Reproduce:
1. touch /.autorelabel
2. reboot


Actual results:

* system boots over and over again and relabels filesystem everytime

* some files (all SELinux policy .pp modules) are corrupted


Expected results:

* systems reboots only once

Comment 1 Enrico Scholz 2016-10-15 20:56:15 UTC

'strace -f -p 1' and 'systemctl --force reboot' shows

| munmap(0x7f72bd53c000, 1359872)         = 0
| open("/dev/watchdog", O_WRONLY|O_CLOEXEC) = 3
| ioctl(3, SNDRV_RAWMIDI_IOCTL_PVERSION or WDIOC_GETSUPPORT, 0x7ffe87d3b9d0) = 0
| sendmsg(37, {msg_name(0)=NULL, msg_iov(4)=[{"PRIORITY=6\nSYSLOG_FACILITY=3\nCODE_FILE=src/shared/watchdog.c\nCODE_LINE=87\nCODE_FUNCTION=open_watchdog\nSYSLOG_IDENTIFIER=systemd\n", 128}, {"MESSAGE=", 8}, {"Hardware watchdog 'i6300ESB timer', version 0", 45}, {"\n", 1}], msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 182
| ioctl(3, WDIOC_SETTIMEOUT, 0x7ffe87d3b95ESC[HESC

  [the "ESC[..." strings are the grub boot menu)]

without a prior unmounting or syncing of disks.

Comment 4 David Kaspar // Dee'Kej 2017-04-20 10:51:42 UTC

The pull-request for this change is now merged into RHEL-7 branch:
https://github.com/fedora-sysv/initscripts/pull/91

Comment 5 David Kaspar // Dee'Kej 2017-05-03 10:24:57 UTC

This is now part of RHEL-7 branch:
https://github.com/fedora-sysv/initscripts/pull/95

Comment 13 errata-xmlrpc 2017-08-01 07:29:01 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:2286