cgroup: reject cgroup names with ' '
commit 71b1fb5c4473a5b1e601d41b109bdfe001ec82e0 upstream.
/proc/<pid>/cgroup contains one cgroup path on each line. If cgroup names are
allowed to contain "\n", applications cannot parse /proc/<pid>/cgroup safely.
Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
[lizf: Backported to 3.4:
- adjust context
- s/name/dentry->d_name.name/]
Signed-off-by: Zefan Li <lizefan@huawei.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 24e15ba..b89ff1c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3877,6 +3877,11 @@
{
struct cgroup *c_parent = dentry->d_parent->d_fsdata;
+ /* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
+ */
+ if (strchr(dentry->d_name.name, '\n'))
+ return -EINVAL;
+
/* the vfs holds inode->i_mutex already */
return cgroup_create(c_parent, dentry, mode | S_IFDIR);
}