This is a note to let you know that I've just added the patch titled
unfuck sysfs_mount()
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
unfuck-sysfs_mount.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7b745a4e4051e1bbce40e0b1c2cf636c70583aa4 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date: Mon, 14 May 2018 00:03:34 -0400
Subject: unfuck sysfs_mount()
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit 7b745a4e4051e1bbce40e0b1c2cf636c70583aa4 upstream.
new_sb is left uninitialized in case of early failures in kernfs_mount_ns(),
and while IS_ERR(root) is true in all such cases, using IS_ERR(root) || !new_sb
is not a solution - IS_ERR(root) is true in some cases when new_sb is true.
Make sure new_sb is initialized (and matches the reality) in all cases and
fix the condition for dropping kobj reference - we want it done precisely
in those situations where the reference has not been transferred into a new
super_block instance.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/sysfs/mount.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -28,7 +28,7 @@ static struct dentry *sysfs_mount(struct
{
struct dentry *root;
void *ns;
- bool new_sb;
+ bool new_sb = false;
if (!(flags & MS_KERNMOUNT)) {
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
@@ -38,9 +38,9 @@ static struct dentry *sysfs_mount(struct
ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
root = kernfs_mount_ns(fs_type, flags, sysfs_root,
SYSFS_MAGIC, &new_sb, ns);
- if (IS_ERR(root) || !new_sb)
+ if (!new_sb)
kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
- else if (new_sb)
+ else if (!IS_ERR(root))
root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
return root;
Patches currently in stable-queue which might be from viro@xxxxxxxxxxxxxxxxxx are
queue-4.14/unfuck-sysfs_mount.patch
queue-4.14/kernfs-deal-with-kernfs_fill_super-failures.patch
