All of
 help / color / mirror / Atom feed
* patch "debugfs: fix security_locked_down() call for SELinux" added to driver-core-linus
@ 2021-05-21 11:13 gregkh
  0 siblings, 0 replies; only message in thread
From: gregkh @ 2021-05-21 11:13 UTC (permalink / raw)
  To: omosnace, gregkh, stable

This is a note to let you know that I've just added the patch titled

    debugfs: fix security_locked_down() call for SELinux

to my driver-core git tree which can be found at
in the driver-core-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.

From 5881fa8dc2de9697a89451f6518e8b3a796c09c6 Mon Sep 17 00:00:00 2001
From: Ondrej Mosnacek <>
Date: Fri, 7 May 2021 14:53:04 +0200
Subject: debugfs: fix security_locked_down() call for SELinux

When (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) is zero, then
the SELinux implementation of the locked_down hook might report a denial
even though the operation would actually be allowed.

To fix this, make sure that security_locked_down() is called only when
the return value will be taken into account (i.e. when changing one of
the problematic attributes).

Note: this was introduced by commit 5496197f9b08 ("debugfs: Restrict
debugfs when the kernel is locked down"), but it didn't matter at that
time, as the SELinux support came in later.

Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown")
Cc: stable <>
Signed-off-by: Ondrej Mosnacek <>
Signed-off-by: Greg Kroah-Hartman <>
 fs/debugfs/inode.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 1d252164d97b..8129a430d789 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -45,10 +45,13 @@ static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS;
 static int debugfs_setattr(struct user_namespace *mnt_userns,
 			   struct dentry *dentry, struct iattr *ia)
-	int ret = security_locked_down(LOCKDOWN_DEBUGFS);
+	int ret;
-	if (ret && (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
-		return ret;
+	if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) {
+		ret = security_locked_down(LOCKDOWN_DEBUGFS);
+		if (ret)
+			return ret;
+	}
 	return simple_setattr(&init_user_ns, dentry, ia);

^ permalink raw reply related	[flat|nested] only message in thread

only message in thread, other threads:[~2021-05-21 11:13 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-21 11:13 patch "debugfs: fix security_locked_down() call for SELinux" added to driver-core-linus gregkh

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.