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.
In addition to .extra1, .extra2 is set to SYSCTL_ONE. The sysctl is
thus bounded between 0 and 1.
Fixes: 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table")
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
arch/sh/kernel/vsyscall/vsyscall.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index d80dd92a483af..1563dcc55fd32 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -37,8 +37,9 @@ static const struct ctl_table vdso_table[] = {
.data = &vdso_enabled,
.maxlen = sizeof(vdso_enabled),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
},
};
--
2.48.1
