Revert "proc: add config & param to block forcing mem writes"
This reverts commit 72291ae00f
.
This commit is contained in:
parent
5d007952c1
commit
8b17ca6430
3 changed files with 1 additions and 102 deletions
|
@ -4163,16 +4163,6 @@
|
||||||
printk.time= Show timing data prefixed to each printk message line
|
printk.time= Show timing data prefixed to each printk message line
|
||||||
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
|
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
|
||||||
|
|
||||||
proc_mem.force_override= [KNL]
|
|
||||||
Format: {always | ptrace | never}
|
|
||||||
Traditionally /proc/pid/mem allows memory permissions to be
|
|
||||||
overridden without restrictions. This option may be set to
|
|
||||||
restrict that. Can be one of:
|
|
||||||
- 'always': traditional behavior always allows mem overrides.
|
|
||||||
- 'ptrace': only allow mem overrides for active ptracers.
|
|
||||||
- 'never': never allow mem overrides.
|
|
||||||
If not specified, default is the CONFIG_PROC_MEM_* choice.
|
|
||||||
|
|
||||||
processor.max_cstate= [HW,ACPI]
|
processor.max_cstate= [HW,ACPI]
|
||||||
Limit processor to maximum C-state
|
Limit processor to maximum C-state
|
||||||
max_cstate=9 overrides any DMI blacklist limit.
|
max_cstate=9 overrides any DMI blacklist limit.
|
||||||
|
|
|
@ -86,7 +86,6 @@
|
||||||
#include <linux/elf.h>
|
#include <linux/elf.h>
|
||||||
#include <linux/pid_namespace.h>
|
#include <linux/pid_namespace.h>
|
||||||
#include <linux/user_namespace.h>
|
#include <linux/user_namespace.h>
|
||||||
#include <linux/fs_parser.h>
|
|
||||||
#include <linux/fs_struct.h>
|
#include <linux/fs_struct.h>
|
||||||
#include <linux/slab.h>
|
#include <linux/slab.h>
|
||||||
#include <linux/sched/autogroup.h>
|
#include <linux/sched/autogroup.h>
|
||||||
|
@ -124,40 +123,6 @@
|
||||||
static u8 nlink_tid __ro_after_init;
|
static u8 nlink_tid __ro_after_init;
|
||||||
static u8 nlink_tgid __ro_after_init;
|
static u8 nlink_tgid __ro_after_init;
|
||||||
|
|
||||||
enum proc_mem_force {
|
|
||||||
PROC_MEM_FORCE_ALWAYS,
|
|
||||||
PROC_MEM_FORCE_PTRACE,
|
|
||||||
PROC_MEM_FORCE_NEVER
|
|
||||||
};
|
|
||||||
|
|
||||||
static enum proc_mem_force proc_mem_force_override __ro_after_init =
|
|
||||||
IS_ENABLED(CONFIG_PROC_MEM_NO_FORCE) ? PROC_MEM_FORCE_NEVER :
|
|
||||||
IS_ENABLED(CONFIG_PROC_MEM_FORCE_PTRACE) ? PROC_MEM_FORCE_PTRACE :
|
|
||||||
PROC_MEM_FORCE_ALWAYS;
|
|
||||||
|
|
||||||
static const struct constant_table proc_mem_force_table[] __initconst = {
|
|
||||||
{ "always", PROC_MEM_FORCE_ALWAYS },
|
|
||||||
{ "ptrace", PROC_MEM_FORCE_PTRACE },
|
|
||||||
{ "never", PROC_MEM_FORCE_NEVER },
|
|
||||||
{ }
|
|
||||||
};
|
|
||||||
|
|
||||||
static int __init early_proc_mem_force_override(char *buf)
|
|
||||||
{
|
|
||||||
if (!buf)
|
|
||||||
return -EINVAL;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* lookup_constant() defaults to proc_mem_force_override to preseve
|
|
||||||
* the initial Kconfig choice in case an invalid param gets passed.
|
|
||||||
*/
|
|
||||||
proc_mem_force_override = lookup_constant(proc_mem_force_table,
|
|
||||||
buf, proc_mem_force_override);
|
|
||||||
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
early_param("proc_mem.force_override", early_proc_mem_force_override);
|
|
||||||
|
|
||||||
struct pid_entry {
|
struct pid_entry {
|
||||||
const char *name;
|
const char *name;
|
||||||
unsigned int len;
|
unsigned int len;
|
||||||
|
@ -926,28 +891,6 @@ static int mem_open(struct inode *inode, struct file *file)
|
||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
||||||
static bool proc_mem_foll_force(struct file *file, struct mm_struct *mm)
|
|
||||||
{
|
|
||||||
struct task_struct *task;
|
|
||||||
bool ptrace_active = false;
|
|
||||||
|
|
||||||
switch (proc_mem_force_override) {
|
|
||||||
case PROC_MEM_FORCE_NEVER:
|
|
||||||
return false;
|
|
||||||
case PROC_MEM_FORCE_PTRACE:
|
|
||||||
task = get_proc_task(file_inode(file));
|
|
||||||
if (task) {
|
|
||||||
ptrace_active = READ_ONCE(task->ptrace) &&
|
|
||||||
READ_ONCE(task->mm) == mm &&
|
|
||||||
READ_ONCE(task->parent) == current;
|
|
||||||
put_task_struct(task);
|
|
||||||
}
|
|
||||||
return ptrace_active;
|
|
||||||
default:
|
|
||||||
return true;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
static ssize_t mem_rw(struct file *file, char __user *buf,
|
static ssize_t mem_rw(struct file *file, char __user *buf,
|
||||||
size_t count, loff_t *ppos, int write)
|
size_t count, loff_t *ppos, int write)
|
||||||
{
|
{
|
||||||
|
@ -968,9 +911,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
|
||||||
if (!mmget_not_zero(mm))
|
if (!mmget_not_zero(mm))
|
||||||
goto free;
|
goto free;
|
||||||
|
|
||||||
flags = write ? FOLL_WRITE : 0;
|
flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
|
||||||
if (proc_mem_foll_force(file, mm))
|
|
||||||
flags |= FOLL_FORCE;
|
|
||||||
|
|
||||||
while (count > 0) {
|
while (count > 0) {
|
||||||
size_t this_len = min_t(size_t, count, PAGE_SIZE);
|
size_t this_len = min_t(size_t, count, PAGE_SIZE);
|
||||||
|
|
|
@ -19,38 +19,6 @@ config SECURITY_DMESG_RESTRICT
|
||||||
|
|
||||||
If you are unsure how to answer this question, answer N.
|
If you are unsure how to answer this question, answer N.
|
||||||
|
|
||||||
choice
|
|
||||||
prompt "Allow /proc/pid/mem access override"
|
|
||||||
default PROC_MEM_ALWAYS_FORCE
|
|
||||||
help
|
|
||||||
Traditionally /proc/pid/mem allows users to override memory
|
|
||||||
permissions for users like ptrace, assuming they have ptrace
|
|
||||||
capability.
|
|
||||||
|
|
||||||
This allows people to limit that - either never override, or
|
|
||||||
require actual active ptrace attachment.
|
|
||||||
|
|
||||||
Defaults to the traditional behavior (for now)
|
|
||||||
|
|
||||||
config PROC_MEM_ALWAYS_FORCE
|
|
||||||
bool "Traditional /proc/pid/mem behavior"
|
|
||||||
help
|
|
||||||
This allows /proc/pid/mem accesses to override memory mapping
|
|
||||||
permissions if you have ptrace access rights.
|
|
||||||
|
|
||||||
config PROC_MEM_FORCE_PTRACE
|
|
||||||
bool "Require active ptrace() use for access override"
|
|
||||||
help
|
|
||||||
This allows /proc/pid/mem accesses to override memory mapping
|
|
||||||
permissions for active ptracers like gdb.
|
|
||||||
|
|
||||||
config PROC_MEM_NO_FORCE
|
|
||||||
bool "Never"
|
|
||||||
help
|
|
||||||
Never override memory mapping permissions
|
|
||||||
|
|
||||||
endchoice
|
|
||||||
|
|
||||||
config SECURITY
|
config SECURITY
|
||||||
bool "Enable different security models"
|
bool "Enable different security models"
|
||||||
depends on SYSFS
|
depends on SYSFS
|
||||||
|
|
Loading…
Reference in a new issue