proc: remove kernel.maps_protect

After commit 831830b5a2b5d413407adf380ef62fe17d6fcbf2 aka
"restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace"
sysctl stopped being relevant because commit moved security checks from ->show
time to ->start time (mm_for_maps()).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <kees.cook@canonical.com>

1 files changed, 1 insertions, 15 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 73d1891ee625..4806830ea2a1 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -210,9 +210,6 @@ static int show_map(struct seq_file *m, void *v)
         dev_t dev = 0;
         int len;
 
-        if (maps_protect && !ptrace_may_access(task, PTRACE_MODE_READ))
-                return -EACCES;
-
         if (file) {
                 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
                 dev = inode->i_sb->s_dev;
@@ -742,22 +739,11 @@ const struct file_operations proc_pagemap_operations = {
 #ifdef CONFIG_NUMA
 extern int show_numa_map(struct seq_file *m, void *v);
 
-static int show_numa_map_checked(struct seq_file *m, void *v)
-{
-        struct proc_maps_private *priv = m->private;
-        struct task_struct *task = priv->task;
-
-        if (maps_protect && !ptrace_may_access(task, PTRACE_MODE_READ))
-                return -EACCES;
-
-        return show_numa_map(m, v);
-}
-
 static const struct seq_operations proc_pid_numa_maps_op = {
         .start  = m_start,
         .next   = m_next,
         .stop   = m_stop,
-        .show   = show_numa_map_checked
+        .show   = show_numa_map,
 };
 
 static int numa_maps_open(struct inode *inode, struct file *file)