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authorAl Viro <viro@zeniv.linux.org.uk>2018-05-14 00:03:34 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2018-05-21 14:30:09 -0400
commit7b745a4e4051e1bbce40e0b1c2cf636c70583aa4 (patch)
treec5fd8a796d75053bccf60ee4376b4872d10e7918
parent82382acec0c97b91830fff7130d0acce4ac4f3f3 (diff)
unfuck sysfs_mount()
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>
-rw-r--r--fs/sysfs/mount.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index b428d317ae92..92682fcc41f6 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -25,7 +25,7 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
25{ 25{
26 struct dentry *root; 26 struct dentry *root;
27 void *ns; 27 void *ns;
28 bool new_sb; 28 bool new_sb = false;
29 29
30 if (!(flags & SB_KERNMOUNT)) { 30 if (!(flags & SB_KERNMOUNT)) {
31 if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET)) 31 if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
@@ -35,9 +35,9 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
35 ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); 35 ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
36 root = kernfs_mount_ns(fs_type, flags, sysfs_root, 36 root = kernfs_mount_ns(fs_type, flags, sysfs_root,
37 SYSFS_MAGIC, &new_sb, ns); 37 SYSFS_MAGIC, &new_sb, ns);
38 if (IS_ERR(root) || !new_sb) 38 if (!new_sb)
39 kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); 39 kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
40 else if (new_sb) 40 else if (!IS_ERR(root))
41 root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE; 41 root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
42 42
43 return root; 43 return root;