On Tue 17-12-24 14:29:07, nicolas.bouchinet@xxxxxxxxxxx wrote:
> 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>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> kernel/sysctl.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 79e6cb1d5c48f..6d8a4fceb79aa 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2194,8 +2194,9 @@ 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,
> + .extra1 = SYSCTL_ONE,
> },
> #endif
> {
> --
> 2.47.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
