cgroup/bpf: only cgroup v2 can be attached by bpf programs

[ Upstream commit 2190df6c91 ]

Only cgroup v2 can be attached by bpf programs, so this patch introduces
that cgroup_bpf_inherit and cgroup_bpf_offline can only be called in
cgroup v2, and this can fix the memleak mentioned by commit 04f8ef5643
("cgroup: Fix memory leak caused by missing cgroup_bpf_offline"), which
has been reverted.

Fixes: 2b0d3d3e4f ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Fixes: 4bfc0bb2c6 ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhesjlfdw@46zxhg5bdnr7/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Chen Ridong 2024-10-18 08:15:20 +00:00 committed by Greg Kroah-Hartman
parent c4e5e64d28
commit 8c222df370

View File

@ -2119,8 +2119,10 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
if (ret)
goto exit_stats;
ret = cgroup_bpf_inherit(root_cgrp);
WARN_ON_ONCE(ret);
if (root == &cgrp_dfl_root) {
ret = cgroup_bpf_inherit(root_cgrp);
WARN_ON_ONCE(ret);
}
trace_cgroup_setup_root(root);
@ -5626,9 +5628,11 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name,
if (ret)
goto out_kernfs_remove;
ret = cgroup_bpf_inherit(cgrp);
if (ret)
goto out_psi_free;
if (cgrp->root == &cgrp_dfl_root) {
ret = cgroup_bpf_inherit(cgrp);
if (ret)
goto out_psi_free;
}
/*
* New cgroup inherits effective freeze counter, and
@ -5946,7 +5950,8 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
cgroup1_check_for_release(parent);
cgroup_bpf_offline(cgrp);
if (cgrp->root == &cgrp_dfl_root)
cgroup_bpf_offline(cgrp);
/* put the base reference */
percpu_ref_kill(&cgrp->self.refcnt);