SELinux is preventing some qemu-kvm operations on CentOS Stream 9
Host environment
- Operating system: CentOS Stream release 9
- OS/kernel version: Linux rd02 5.14.0-437.el9.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Apr 9 12:57:02 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
- Architecture: x86_64
- QEMU flavor: qemu-img
- QEMU version: qemu-img version 8.2.0 (qemu-kvm-8.2.0-11.el9)
- QEMU command line: This has happened while creating a VM, either from cockpit and also from command line with virt-install.
Emulated/Virtualized environment
- Operating system: CentOS Stream release 9
- OS/kernel version: Linux ipa03 5.14.0-437.el9.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Apr 9 12:57:02 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
- Architecture: x86_64
Description of problem
Some operations are being denied by SELinux.
First it was read access on file max_map_count, then open and getattr access on /proc/sys/vm/max_map_count (same file but with full path).
All have been fixed by creating and applying a semodule with the TE policy shown on "Additional Information" below.
May 2 18:01:00 rd02 setroubleshoot[14757]: SELinux is preventing /usr/libexec/qemu-kvm from read access on the file max_map_count. For complete SELinux messages run: sealert -l c92d5506-0b40-4bc8-be6a-133fe360014d
May 2 18:01:00 rd02 setroubleshoot[14757]: SELinux is preventing /usr/libexec/qemu-kvm from read access on the file max_map_count.#012#012***** Plugin qemu_file_image (98.8 confidence) suggests *******************#012#012If max_map_count is a virtualization target#012Then you need to change the label on max_map_count'#012Do#012# semanage fcontext -a -t virt_image_t 'max_map_count'#012# restorecon -v 'max_map_count'#012#012***** Plugin catchall (2.13 confidence) suggests **************************#012#012If you believe that qemu-kvm should be allowed read access on the max_map_count file by default.#012Then you should report this as a bug.#012You can generate a local policy module to allow this access.#012Do#012allow this access for now by executing:#012# ausearch -c 'qemu-kvm' --raw | audit2allow -M my-qemukvm#012# semodule -X 300 -i my-qemukvm.pp#012
---
May 3 10:24:58 rd02 setroubleshoot[3981]: SELinux is preventing /usr/libexec/qemu-kvm from open access on the file /proc/sys/vm/max_map_count. For complete SELinux messages run: sealert -l 655af27c-6bc7-4278-9aad-7fc99929d24b
May 3 10:24:58 rd02 setroubleshoot[3981]: SELinux is preventing /usr/libexec/qemu-kvm from open access on the file /proc/sys/vm/max_map_count.#012#012***** Plugin qemu_file_image (98.8 confidence) suggests *******************#012#012If max_map_count is a virtualization target#012Then you need to change the label on max_map_count'#012Do#012# semanage fcontext -a -t virt_image_t '/proc/sys/vm/max_map_count'#012# restorecon -v '/proc/sys/vm/max_map_count'#012#012***** Plugin catchall (2.13 confidence) suggests **************************#012#012If you believe that qemu-kvm should be allowed open access on the max_map_count file by default.#012Then you should report this as a bug.#012You can generate a local policy module to allow this access.#012Do#012allow this access for now by executing:#012# ausearch -c 'qemu-kvm' --raw | audit2allow -M my-qemukvm#012# semodule -X 300 -i my-qemukvm.pp#012
---
May 3 10:41:17 rd02 setroubleshoot[6894]: SELinux is preventing /usr/libexec/qemu-kvm from getattr access on the file /proc/sys/vm/max_map_count. For complete SELinux messages run: sealert -l db78c5b9-3890-44d4-a40e-d4011ad42913
May 3 10:41:17 rd02 setroubleshoot[6894]: SELinux is preventing /usr/libexec/qemu-kvm from getattr access on the file /proc/sys/vm/max_map_count.#012#012***** Plugin qemu_file_image (98.8 confidence) suggests *******************#012#012If max_map_count is a virtualization target#012Then you need to change the label on max_map_count'#012Do#012# semanage fcontext -a -t virt_image_t '/proc/sys/vm/max_map_count'#012# restorecon -v '/proc/sys/vm/max_map_count'#012#012***** Plugin catchall (2.13 confidence) suggests **************************#012#012If you believe that qemu-kvm should be allowed getattr access on the max_map_count file by default.#012Then you should report this as a bug.#012You can generate a local policy module to allow this access.#012Do#012allow this access for now by executing:#012# ausearch -c 'qemu-kvm' --raw | audit2allow -M my-qemukvm#012# semodule -X 300 -i my-qemukvm.pp#012
Steps to reproduce
- On a CentOS Stream 9 system with a selinux enforced, create a VM and install an OS with cockpit or with virt-install.
- example with virt-install:
virt-install --connect qemu:///system --os-variant centos-stream9 --reinstall ipa03 --wait -1 --location /mnt/CentOS-Stream9.iso - Check the SELinux logs, either on cockpit or on /var/log/messages
Additional information
TE module that solved the issue, created with ausearch -c 'qemu-kvm' --raw | audit2allow -M my-qemukvm
module my-qemukvm 1.1;
require {
type sysctl_vm_t;
type svirt_t;
class file { getattr open read };
}
#============= svirt_t ==============
#!!!! This avc is allowed in the current policy
allow svirt_t sysctl_vm_t:file read;
allow svirt_t sysctl_vm_t:file { getattr open };