sysctl: add some missing input constraint checks

cb16e95f · Petr Holasek <[email protected]> · 2011-03-23 16:43:09 -07:00

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 <[email protected]>
Acked-by: Dave Young <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Wu Fengguang <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: cb16e95fa2996743a6e80a665ed2ed0590bd38cf
Parents: 256c53a6

Changes

2 files changed · +18 −5

File	Status	Add	Del	Content
fs/drop_caches.c	modified	+5	−1	View file
kernel/sysctl.c	modified	+13	−4	View file

fs/drop_caches.c

View file

diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 2195c21..816f88e 100644
--- a/fs/drop_caches.c
+++ b/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);

kernel/sysctl.c

View file

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 40245d6..97ab169 100644
--- a/kernel/sysctl.c
+++ b/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
 	{