| From | Greg Kroah-Hartman <> | Subject | [ 063/100] proc: Use nd_jump_link in proc_ns_follow_link | Date | Tue, 12 Mar 2013 15:31:48 -0700 |
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3.8-stable review patch. If anyone has any objections, please let me know.
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From: "Eric W. Biederman" <ebiederm@xmission.com>
commit db04dc679bcc780ad6907943afe24a30de974a1b upstream.
Update proc_ns_follow_link to use nd_jump_link instead of just manually updating nd.path.dentry.
This fixes the BUG_ON(nd->inode != parent->d_inode) reported by Dave Jones and reproduced trivially with mkdir /proc/self/ns/uts/a.
Sigh it looks like the VFS change to require use of nd_jump_link happend while proc_ns_follow_link was baking and since the common case of proc_ns_follow_link continued to work without problems the need for making this change was overlooked.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/proc/namespaces.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -118,7 +118,7 @@ static void *proc_ns_follow_link(struct struct super_block *sb = inode->i_sb; struct proc_inode *ei = PROC_I(inode); struct task_struct *task; - struct dentry *ns_dentry; + struct path ns_path; void *error = ERR_PTR(-EACCES); task = get_proc_task(inode); @@ -128,14 +128,14 @@ static void *proc_ns_follow_link(struct if (!ptrace_may_access(task, PTRACE_MODE_READ)) goto out_put_task; - ns_dentry = proc_ns_get_dentry(sb, task, ei->ns_ops); - if (IS_ERR(ns_dentry)) { - error = ERR_CAST(ns_dentry); + ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns_ops); + if (IS_ERR(ns_path.dentry)) { + error = ERR_CAST(ns_path.dentry); goto out_put_task; } - dput(nd->path.dentry); - nd->path.dentry = ns_dentry; + ns_path.mnt = mntget(nd->path.mnt); + nd_jump_link(nd, &ns_path); error = NULL; out_put_task:
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