]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
cgroup1: don't allow '\n' in renaming
authorAlexander Kuznetsov <wwfq@yandex-team.ru>
Wed, 9 Jun 2021 07:17:19 +0000 (10:17 +0300)
committerTejun Heo <tj@kernel.org>
Thu, 10 Jun 2021 13:58:50 +0000 (09:58 -0400)
commitb7e24eb1caa5f8da20d405d262dba67943aedc42
tree69baa641c0dba6e5b9c25ff0d86fd8226d262791
parent08b2b6fdf6b26032f025084ce2893924a0cdb4a2
cgroup1: don't allow '\n' in renaming

cgroup_mkdir() have restriction on newline usage in names:
$ mkdir $'/sys/fs/cgroup/cpu/test\ntest2'
mkdir: cannot create directory
'/sys/fs/cgroup/cpu/test\ntest2': Invalid argument

But in cgroup1_rename() such check is missed.
This allows us to make /proc/<pid>/cgroup unparsable:
$ mkdir /sys/fs/cgroup/cpu/test
$ mv /sys/fs/cgroup/cpu/test $'/sys/fs/cgroup/cpu/test\ntest2'
$ echo $$ > $'/sys/fs/cgroup/cpu/test\ntest2'
$ cat /proc/self/cgroup
11:pids:/
10:freezer:/
9:hugetlb:/
8:cpuset:/
7:blkio:/user.slice
6:memory:/user.slice
5:net_cls,net_prio:/
4:perf_event:/
3:devices:/user.slice
2:cpu,cpuacct:/test
test2
1:name=systemd:/
0::/

Signed-off-by: Alexander Kuznetsov <wwfq@yandex-team.ru>
Reported-by: Andrey Krasichkov <buglloc@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
kernel/cgroup/cgroup-v1.c