When mounting a cgroup hierarchy with disabled controller in cgroup v1,
all available controllers will be attached.
For example, boot with cgroup_no_v1=cpu or cgroup_disable=cpu, and then
mount with "mount -t cgroup -ocpu cpu /sys/fs/cgroup/cpu", then all
enabled controllers will be attached except cpu.
Fix this by adding disabled controller check in cgroup1_parse_param().
If the specified controller is disabled, just return error with information
"Disabled controller xx" rather than attaching all the other enabled
controllers.
Fixes: f5dfb5315d34 ("cgroup: take options parsing into ->parse_monolithic()")
Signed-off-by: Chen Zhou <[email protected]>
Reviewed-by: Zefan Li <[email protected]>
---
Changes in v3:
- Update the description of commit message.
- Add Reviewed-by from Zefan.
Changes in v2:
- Fix line over 80 characters warning.
---
kernel/cgroup/cgroup-v1.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 32596fdbcd5b..a5751784ad74 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -917,6 +917,9 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
for_each_subsys(ss, i) {
if (strcmp(param->key, ss->legacy_name))
continue;
+ if (!cgroup_ssid_enabled(i) || cgroup1_ssid_disabled(i))
+ return invalfc(fc, "Disabled controller '%s'",
+ param->key);
ctx->subsys_mask |= (1 << i);
return 0;
}
--
2.20.1
On Fri, Jan 15, 2021 at 05:37:17PM +0800, Chen Zhou <[email protected]> wrote:
> [...]
> kernel/cgroup/cgroup-v1.c | 3 +++
> 1 file changed, 3 insertions(+)
Reviewed-by: Michal Koutn? <[email protected]>
On Fri, Jan 15, 2021 at 05:37:17PM +0800, Chen Zhou wrote:
> When mounting a cgroup hierarchy with disabled controller in cgroup v1,
> all available controllers will be attached.
> For example, boot with cgroup_no_v1=cpu or cgroup_disable=cpu, and then
> mount with "mount -t cgroup -ocpu cpu /sys/fs/cgroup/cpu", then all
> enabled controllers will be attached except cpu.
>
> Fix this by adding disabled controller check in cgroup1_parse_param().
> If the specified controller is disabled, just return error with information
> "Disabled controller xx" rather than attaching all the other enabled
> controllers.
>
> Fixes: f5dfb5315d34 ("cgroup: take options parsing into ->parse_monolithic()")
> Signed-off-by: Chen Zhou <[email protected]>
> Reviewed-by: Zefan Li <[email protected]>
Applied to cgroup/for-5.11-fixes.
Thanks.
--
tejun