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sysctl: add some missing input constraint checks

Add boundaries of allowed input ranges for: dirty_expire_centisecs,
drop_caches, overcommit_memory, page-cluster and panic_on_oom.

Signed-off-by: Petr Holasek <pholasek@redhat.com>
Acked-by: Dave Young <hidave.darkstar@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
master
Petr Holasek 11 years ago
committed by Linus Torvalds
parent
commit
cb16e95fa2
  1. 6
      fs/drop_caches.c
  2. 17
      kernel/sysctl.c

6
fs/drop_caches.c

@ -45,7 +45,11 @@ static void drop_slab(void)
int drop_caches_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
proc_dointvec_minmax(table, write, buffer, length, ppos);
int ret;
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (ret)
return ret;
if (write) {
if (sysctl_drop_caches & 1)
iterate_supers(drop_pagecache_sb, NULL);

17
kernel/sysctl.c

@ -117,6 +117,7 @@ static int neg_one = -1;
static int zero;
static int __maybe_unused one = 1;
static int __maybe_unused two = 2;
static int __maybe_unused three = 3;
static unsigned long one_ul = 1;
static int one_hundred = 100;
#ifdef CONFIG_PRINTK
@ -971,14 +972,18 @@ static struct ctl_table vm_table[] = {
.data = &sysctl_overcommit_memory,
.maxlen = sizeof(sysctl_overcommit_memory),
.mode = 0644,
.proc_handler = proc_dointvec,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
.extra2 = &two,
},
{
.procname = "panic_on_oom",
.data = &sysctl_panic_on_oom,
.maxlen = sizeof(sysctl_panic_on_oom),
.mode = 0644,
.proc_handler = proc_dointvec,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
.extra2 = &two,
},
{
.procname = "oom_kill_allocating_task",
@ -1006,7 +1011,8 @@ static struct ctl_table vm_table[] = {
.data = &page_cluster,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
},
{
.procname = "dirty_background_ratio",
@ -1054,7 +1060,8 @@ static struct ctl_table vm_table[] = {
.data = &dirty_expire_interval,
.maxlen = sizeof(dirty_expire_interval),
.mode = 0644,
.proc_handler = proc_dointvec,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
},
{
.procname = "nr_pdflush_threads",
@ -1130,6 +1137,8 @@ static struct ctl_table vm_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = drop_caches_sysctl_handler,
.extra1 = &one,
.extra2 = &three,
},
#ifdef CONFIG_COMPACTION
{

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