From: Li Zefan Date: Tue, 2 Feb 2010 21:44:10 +0000 (-0800) Subject: cgroups: fix to return errno in a failure path X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4528fd0595847c2078b59f24800e751c2d6b7e41;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git cgroups: fix to return errno in a failure path In cgroup_create(), if alloc_css_id() returns failure, the errno is not propagated to userspace, so mkdir will fail silently. To trigger this bug, we mount blkio (or memory subsystem), and create more then 65534 cgroups. (The number of cgroups is limited to 65535 if a subsystem has use_id == 1) # mount -t cgroup -o blkio xxx /mnt # for ((i = 0; i < 65534; i++)); do mkdir /mnt/$i; done # mkdir /mnt/65534 (should return ENOSPC) # Signed-off-by: Li Zefan Acked-by: Serge Hallyn Acked-by: Paul Menage Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 1fbcc748044a..aa3bee566446 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2936,14 +2936,17 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, for_each_subsys(root, ss) { struct cgroup_subsys_state *css = ss->create(ss, cgrp); + if (IS_ERR(css)) { err = PTR_ERR(css); goto err_destroy; } init_cgroup_css(css, ss, cgrp); - if (ss->use_id) - if (alloc_css_id(ss, parent, cgrp)) + if (ss->use_id) { + err = alloc_css_id(ss, parent, cgrp); + if (err) goto err_destroy; + } /* At error, ->destroy() callback has to free assigned ID. */ }