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| author | Al Viro <viro@zeniv.linux.org.uk> | 2018-05-14 00:03:34 -0400 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2021-06-30 08:48:55 -0400 |
| commit | 68fed0725820073d37e487bfa7eeb73eb0e63478 (patch) | |
| tree | 8b7e2c5fd276e42dd61591eb86b2597509f7acbe /fs/sysfs/mount.c | |
| parent | e83ca3bdb895e581a6c541515e9fd2cfb9e60ed4 (diff) | |
| download | linux-rt-68fed0725820073d37e487bfa7eeb73eb0e63478.tar.gz | |
unfuck sysfs_mount()
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@zeniv.linux.org.uk>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs/mount.c')
| -rw-r--r-- | fs/sysfs/mount.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 20b8f82e115b..2bbe84d9c0a8 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -28,7 +28,7 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, { 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 file_system_type *fs_type, 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; |