Commit f4d653dc authored by Paul Moore's avatar Paul Moore
Browse files

selinux: implement the security_uring_cmd() LSM hook 



Add a SELinux access control for the iouring IORING_OP_URING_CMD
command.  This includes the addition of a new permission in the
existing "io_uring" object class: "cmd".  The subject of the new
permission check is the domain of the process requesting access, the
object is the open file which points to the device/file that is the
target of the IORING_OP_URING_CMD operation.  A sample policy rule
is shown below:

  allow <domain> <file>:io_uring { cmd };

Cc: stable@vger.kernel.org
Fixes: ee692a21 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: default avatarPaul Moore <paul@paul-moore.com>
parent 2a584012

security/selinux/hooks.c

+24 −0
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ 
#include <uapi/linux/mount.h>

#include <linux/fsnotify.h>

#include <linux/fanotify.h>

#include <linux/io_uring.h>



#include "avc.h"

#include "objsec.h"
@@ -6987,6 +6988,28 @@ static int selinux_uring_sqpoll(void) 
	return avc_has_perm(&selinux_state, sid, sid,

			    SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);

}



/**

 * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed

 * @ioucmd: the io_uring command structure

 *

 * Check to see if the current domain is allowed to execute an

 * IORING_OP_URING_CMD against the device/file specified in @ioucmd.

 *

 */

static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)

{

	struct file *file = ioucmd->file;

	struct inode *inode = file_inode(file);

	struct inode_security_struct *isec = selinux_inode(inode);

	struct common_audit_data ad;



	ad.type = LSM_AUDIT_DATA_FILE;

	ad.u.file = file;



	return avc_has_perm(&selinux_state, current_sid(), isec->sid,

			    SECCLASS_IO_URING, IO_URING__CMD, &ad);

}

#endif /* CONFIG_IO_URING */



/*
@@ -7231,6 +7254,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { 
#ifdef CONFIG_IO_URING

	LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),

	LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),

	LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),

#endif



	/*

security/selinux/include/classmap.h

+1 −1
Original line number Diff line number Diff line
@@ -253,7 +253,7 @@ const struct security_class_mapping secclass_map[] = { 
	{ "anon_inode",

	  { COMMON_FILE_PERMS, NULL } },

	{ "io_uring",

	  { "override_creds", "sqpoll", NULL } },

	  { "override_creds", "sqpoll", "cmd", NULL } },

	{ NULL }

  };