#include #include "notifier-error-inject.h" static int debugfs_errno_set(void *data, u64 val) { *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0); return 0; } static int debugfs_errno_get(void *data, u64 *val) { *val = *(int *)data; return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set, "%lld\n"); static struct dentry *debugfs_create_errno(const char *name, umode_t mode, struct dentry *parent, int *value) { return debugfs_create_file(name, mode, parent, value, &fops_errno); } static int notifier_err_inject_callback(struct notifier_block *nb, unsigned long val, void *p) { int err = 0; struct notifier_err_inject *err_inject = container_of(nb, struct notifier_err_inject, nb); struct notifier_err_inject_action *action; for (action = err_inject->actions; action->name; action++) { if (action->val == val) { err = action->error; break; } } if (err) pr_info("Injecting error (%d) to %s\n", err, action->name); return notifier_from_errno(err); } struct dentry *notifier_err_inject_dir; EXPORT_SYMBOL_GPL(notifier_err_inject_dir); struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent, struct notifier_err_inject *err_inject, int priority) { struct notifier_err_inject_action *action; umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; struct dentry *dir; struct dentry *actions_dir; err_inject->nb.notifier_call = notifier_err_inject_callback; err_inject->nb.priority = priority; dir = debugfs_create_dir(name, parent); if (!dir) return ERR_PTR(-ENOMEM); actions_dir = debugfs_create_dir("actions", dir); if (!actions_dir) goto fail; for (action = err_inject->actions; action->name; action++) { struct dentry *action_dir; action_dir = debugfs_create_dir(action->name, actions_dir); if (!action_dir) goto fail; /* * Create debugfs r/w file containing action->error. If * notifier call chain is called with action->val, it will * fail with the error code */ if (!debugfs_create_errno("error", mode, action_dir, &action->error)) goto fail; } return dir; fail: debugfs_remove_recursive(dir); return ERR_PTR(-ENOMEM); } EXPORT_SYMBOL_GPL(notifier_err_inject_init); static int __init err_inject_init(void) { notifier_err_inject_dir = debugfs_create_dir("notifier-error-inject", NULL); if (!notifier_err_inject_dir) return -ENOMEM; return 0; } static void __exit err_inject_exit(void) { debugfs_remove_recursive(notifier_err_inject_dir); } module_init(err_inject_init); module_exit(err_inject_exit); MODULE_DESCRIPTION("Notifier error injection module"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Akinobu Mita "); 6feb4a'>root/net/sunrpc/auth.c
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authorTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
committerTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
commit07cd12945551b63ecb1a349d50a6d69d1d6feb4a (patch)
tree75f65eba7eac9277971082a2d5a4cf1370562c0c /net/sunrpc/auth.c
parent7ce7d89f48834cefece7804d38fc5d85382edf77 (diff)
cgroup: don't online subsystems before cgroup_name/path() are operational
While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems before the new cgroup is associated with it kernfs_node. This is fine for cgroup proper but cgroup_name/path() depend on the associated kernfs_node and if a subsystem makes the new cgroup_subsys_state visible, which they're allowed to after onlining, it can lead to NULL dereference. The current code performs cgroup creation and subsystem onlining in cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems visible afterwards. There's no reason to online the subsystems early and we can simply drop cgroup_apply_control_enable() call from cgroup_create() so that the subsystems are onlined and made visible at the same time. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") Cc: stable@vger.kernel.org # v4.6+
Diffstat (limited to 'net/sunrpc/auth.c')