From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 1 Apr 2020 21:10:38 -0700
Subject: mm/compaction: really limit compact_unevictable_allowed to 0 and 1
Patch-mainline: v5.7-rc1
Git-commit: 964b692daf3018ae4b45285c3bcbb2d897cb4b40
References: bsc#1162702

The proc file `compact_unevictable_allowed' should allow 0 and 1 only, the
`extra*' attribues have been set properly but without
proc_dointvec_minmax() as the `proc_handler' the limit will not be
enforced.

Use proc_dointvec_minmax() as the `proc_handler' to enfoce the valid
specified range.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Link: http://lkml.kernel.org/r/20200303202054.gsosv7fsx2ma3cic@linutronix.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 kernel/sysctl.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1492,7 +1492,7 @@ static struct ctl_table vm_table[] = {
 		.data		= &sysctl_compact_unevictable_allowed,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},