Bug 1453114

Summary:	dnsmasq: failed to create inotify for /etc/resolv.conf: Permission denied
Product:	Red Hat Enterprise Linux 7	Reporter:	Gerd Hoffmann <kraxel>
Component:	selinux-policy	Assignee:	Lukas Vrabec <lvrabec>
Status:	CLOSED ERRATA	QA Contact:	Milos Malik <mmalik>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.4	CC:	kraxel, lvrabec, mgrepl, mmalik, plautrba, pvrabec, ssekidde
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	selinux-policy-3.13.1-152.el7	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-01 15:26:23 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:

Description Gerd Hoffmann 2017-05-22 08:02:59 UTC

Description of problem:
libvirt fails to start virtual networks.

Version-Release number of selected component (if applicable):
libvirt-3.2.0-5.el7.x86_64
selinux-policy-3.13.1-145.el7.noarch
systemd-resolved-219-39.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. start libvirt network.

Actual results:

kraxel@broadwell ~/libvirt/net# virsh net-start bios
error: Failed to start network bios
error: internal error: Child process (VIR_BRIDGE_NAME=virbr0 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/bios.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper) unexpected exit status 5:
dnsmasq: failed to create inotify for /etc/resolv.conf: Permission denied

Expected results:
Network starts fine.

Additional info:

resolv.conf is managed by systemd-resolved ans looks this way:

kraxel@broadwell ~/libvirt/net# ll -Z /etc/resolv.conf /run/systemd/resolve/resolv.conf
lrwxrwxrwx. root            root            unconfined_u:object_r:etc_t:s0   /etc/resolv.conf -> /run/systemd/resolve/resolv.conf
-rw-r--r--. systemd-resolve systemd-resolve system_u:object_r:net_conf_t:s0  /run/systemd/resolve/resolv.conf

After "setenforce 0" the network starts fine.

Comment 2 Milos Malik 2017-05-22 08:15:20 UTC

Do you see any SELinux denials as a result of your scenario?

# ausearch -m avc -m user_avc -m selinux_err -m user_selinux_err -i -ts today

Comment 3 Gerd Hoffmann 2017-05-22 08:20:46 UTC

type=PROCTITLE msg=audit(22.05.2017 09:35:15.464:14806) : proctitle=/usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/bios.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
type=SYSCALL msg=audit(22.05.2017 09:35:15.464:14806) : arch=x86_64 syscall=inotify_add_watch success=no exit=EACCES(Permission denied) a0=0x6 a1=0x5614c43dc2d0 a2=0x88 a3=0x5 items=0 ppid=26122 pid=26194 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=dnsmasq exe=/usr/sbin/dnsmasq subj=system_u:system_r:dnsmasq_t:s0-s0:c0.c1023 key=(null)
type=AVC msg=audit(22.05.2017 09:35:15.464:14806) : avc:  denied  { read } for  pid=26194 comm=dnsmasq name=resolve dev="tmpfs" ino=20256 scontext=system_u:system_r:dnsmasq_t:s0-s0:c0.c1023 tcontext=system_u:object_r:systemd_resolved_var_run_t:s0 tclass=dir

Comment 8 errata-xmlrpc 2017-08-01 15:26:23 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-2017:1861