From: Eric W. Biederman Currently if you access a /proc that is not mounted with your processes current pid namespace /proc/self will point at a completely This patch fixes /proc/self to point to the current process if it is available in the particular mount of /proc or to return -ENOENT if the current process is not visible. Signed-off-by: Eric W. Biederman Cc: Pavel Emelyanov Cc: Alexey Dobriyan Cc: Oleg Nesterov Signed-off-by: Andrew Morton --- fs/proc/base.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff -puN fs/proc/base.c~proc-proper-pidns-handling-for-proc-self fs/proc/base.c --- a/fs/proc/base.c~proc-proper-pidns-handling-for-proc-self +++ a/fs/proc/base.c @@ -2002,15 +2002,23 @@ static const struct file_operations proc static int proc_self_readlink(struct dentry *dentry, char __user *buffer, int buflen) { + struct pid_namespace *ns = dentry->d_sb->s_fs_info; + pid_t tgid = task_tgid_nr_ns(current, ns); char tmp[PROC_NUMBUF]; - sprintf(tmp, "%d", task_tgid_vnr(current)); + if (!tgid) + return -ENOENT; + sprintf(tmp, "%d", tgid); return vfs_readlink(dentry,buffer,buflen,tmp); } static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd) { + struct pid_namespace *ns = dentry->d_sb->s_fs_info; + pid_t tgid = task_tgid_nr_ns(current, ns); char tmp[PROC_NUMBUF]; - sprintf(tmp, "%d", task_tgid_vnr(current)); + if (!tgid) + return ERR_PTR(-ENOENT); + sprintf(tmp, "%d", task_tgid_nr_ns(current, ns)); return ERR_PTR(vfs_follow_link(nd,tmp)); } _