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authorLi Zefan <lizefan@huawei.com>2014-04-17 13:53:08 +0800
committerTejun Heo <tj@kernel.org>2014-04-17 11:18:06 -0400
commite37a06f10994c2ba86f54d8f96734f2483a869b8 (patch)
tree6b53563f1b93588d1c40c52f0eecb049b20c5cff /kernel
parentc9eaa447e77efe77b7fa4c953bd62de8297fd6c5 (diff)
downloadlinux-e37a06f10994c2ba86f54d8f96734f2483a869b8.tar.bz2
cgroup: fix the retry path of cgroup_mount()
If we hit the retry path, we'll call parse_cgroupfs_options() again, but the string we pass to it has been modified by the previous call to this function. This bug can be observed by: # mount -t cgroup -o name=foo,cpuset xxx /mnt && umount /mnt && \ mount -t cgroup -o name=foo,cpuset xxx /mnt mount: wrong fs type, bad option, bad superblock on xxx, missing codepage or helper program, or other error ... The second mount passed "name=foo,cpuset" to the parser, and then it hit the retry path and call the parser again, but this time the string passed to the parser is "name=foo". To fix this, we avoid calling parse_cgroupfs_options() again in this case. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 9fcdaa705b6c..11a03d67635a 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1495,7 +1495,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
*/
if (!use_task_css_set_links)
cgroup_enable_task_cg_lists();
-retry:
+
mutex_lock(&cgroup_tree_mutex);
mutex_lock(&cgroup_mutex);
@@ -1503,7 +1503,7 @@ retry:
ret = parse_cgroupfs_options(data, &opts);
if (ret)
goto out_unlock;
-
+retry:
/* look for a matching existing root */
if (!opts.subsys_mask && !opts.none && !opts.name) {
cgrp_dfl_root_visible = true;
@@ -1562,9 +1562,9 @@ retry:
if (!atomic_inc_not_zero(&root->cgrp.refcnt)) {
mutex_unlock(&cgroup_mutex);
mutex_unlock(&cgroup_tree_mutex);
- kfree(opts.release_agent);
- kfree(opts.name);
msleep(10);
+ mutex_lock(&cgroup_tree_mutex);
+ mutex_lock(&cgroup_mutex);
goto retry;
}