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Commit 3bbfe059 authored by Alexey Dobriyan's avatar Alexey Dobriyan
Browse files

proc: remove kernel.maps_protect 



After commit 831830b5 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: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: default avatarKees Cook <kees.cook@canonical.com>
parent 45acb8db

Documentation/filesystems/proc.txt

+0 −7
Original line number Diff line number Diff line
@@ -1332,13 +1332,6 @@ determine whether or not they are still functioning properly. 
Because the NMI watchdog shares registers with oprofile, by disabling the NMI

watchdog, oprofile may have more registers to utilize.



maps_protect

------------



Enables/Disables the protection of the per-process proc entries "maps" and

"smaps".  When enabled, the contents of these files are visible only to

readers that are allowed to ptrace() the given process.



msgmni

------

fs/proc/base.c

+0 −3
Original line number Diff line number Diff line
@@ -148,9 +148,6 @@ static unsigned int pid_entry_count_dirs(const struct pid_entry *entries, 
	return count;

}



int maps_protect;

EXPORT_SYMBOL(maps_protect);



static struct fs_struct *get_fs_struct(struct task_struct *task)

{

	struct fs_struct *fs;

fs/proc/internal.h

+0 −2
Original line number Diff line number Diff line
@@ -45,8 +45,6 @@ do { \ 
extern int nommu_vma_show(struct seq_file *, struct vm_area_struct *);

#endif



extern int maps_protect;



extern int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,

				struct pid *pid, struct task_struct *task);

extern int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,

fs/proc/task_mmu.c

+1 −15
Original line number Diff line number Diff line
@@ -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)

fs/proc/task_nommu.c

+0 −5
Original line number Diff line number Diff line
@@ -110,11 +110,6 @@ int task_statm(struct mm_struct *mm, int *shared, int *text, 
static int show_map(struct seq_file *m, void *_vml)

{

	struct vm_list_struct *vml = _vml;

	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 nommu_vma_show(m, vml->vma);

}