[PATCH v2 2/3] sysctl: Fix underflow value setting risk in vm_table

[nicolas . bouchinet]

From: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx>

Commit 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in
vm_table") fixes underflow value setting risk in vm_table but misses
vdso_enabled sysctl.

vdso_enabled sysctl is initialized with .extra1 value as SYSCTL_ZERO to
avoid negative value writes but the proc_handler is proc_dointvec and not
proc_dointvec_minmax and thus do not uses .extra1 and .extra2.

The following command thus works :

`# echo -1 > /proc/sys/vm/vdso_enabled`

This patch properly sets the proc_handler to proc_dointvec_minmax.

Fixes: 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table")
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx>
---
 kernel/sysctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 79e6cb1d5c48f..37b1c1a760985 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2194,7 +2194,7 @@ static struct ctl_table vm_table[] = {
 		.maxlen		= sizeof(vdso_enabled),
 #endif
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= SYSCTL_ZERO,
 	},
 #endif
-- 
2.47.0