| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.5 118/170] bpf: Fix cgroup ref leak in cgroup_bpf_inherit on out-of-memory | Date | Tue, 31 Mar 2020 10:58:52 +0200 |
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From: Andrii Nakryiko <andriin@fb.com>
commit 1d8006abaab4cb90f81add86e8d1bf9411add05a upstream.
There is no compensating cgroup_bpf_put() for each ancestor cgroup in cgroup_bpf_inherit(). If compute_effective_progs returns error, those cgroups won't be freed ever. Fix it by putting them in cleanup code path.
Fixes: e10360f815ca ("bpf: cgroup: prevent out-of-order release of cgroup bpf") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Link: https://lore.kernel.org/bpf/20200309224017.1063297-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/bpf/cgroup.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -228,6 +228,9 @@ cleanup: for (i = 0; i < NR; i++) bpf_prog_array_free(arrays[i]); + for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p)) + cgroup_bpf_put(p); + percpu_ref_exit(&cgrp->bpf.refcnt); return -ENOMEM;
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