Bug 2191703

Summary:	BUG: selinux-policy missing unconfined_t allow rule for io_uring:cmd permission
Product:	[Fedora] Fedora	Reporter:	Paul Moore <paul>
Component:	selinux-policy	Assignee:	Zdenek Pytela <zpytela>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	dwalsh, lvrabec, mmalik, nknazeko, omosnacek, pkoncity, vmojzis, zpytela
Target Milestone:	---	Keywords:	SELinux, Triaged
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-05-25 07:49:45 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Paul Moore 2023-04-28 20:39:08 UTC

The Fedora Rawhide SELinux policy blocks the io_uring command passthrough operation on /dev/null for the unconfined_t domain.

Reproducible: Always

Steps to Reproduce:
1. Run the audit-testsuite in my 'working-iouring' development branch: https://github.com/pcmoore/misc-audit_testsuite/tree/working-iouring

Actual Results:  
The following audit event is generated:

type=PROCTITLE msg=audit(04/28/2023 16:24:03.598:214) : proctitle=./iouring t2
 
type=SYSCALL msg=audit(04/28/2023 16:24:03.598:214) : arch=x86_64 syscall=io_uring_enter success=yes exit=1 a0=0x4 a1=0x1 a2=0x0 a3=0x0 items=0 ppid=932 pid=1106 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=pts0 ses=1 comm=iouring exe=/root/sources/audit-testsuite/tests/io_uring/iouring subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) 

type=URINGOP msg=audit(04/28/2023 16:24:03.598:214) : uring_op=uring_cmd success=no exit=EACCES(Permission denied) items=0 ppid=932 pid=1106 uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) 

type=AVC msg=audit(04/28/2023 16:24:03.598:214) : avc:  denied  { cmd } for  pid=1106 comm=iouring path=/dev/null dev="devtmpfs" ino=4 scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=io_uring permissive=0 


Expected Results:  
The operation should succeed.

% rpm -q selinux-policy
selinux-policy-38.12-1.fc39.noarch
% uname -r
6.4.0-0.rc0.20230428git33afd4b7.7.2.secnext.fc39.x86_64

Comment 1 Zdenek Pytela 2023-05-05 10:02:49 UTC

Hi Paul,

Thanks for reporting. I've submitted a Fedora PR to address the issue:
https://github.com/fedora-selinux/selinux-policy/pull/1676

You can try the scratchbuild
Checks -> Artifacts -> rpms.zip

to see if the fix is complete.

Comment 2 Paul Moore 2023-05-05 15:26:55 UTC

Thanks Zdenek, that resolves the problem on my test system.