From: Andrii Nakryiko Date: Mon, 9 Mar 2020 22:40:17 +0000 (-0700) Subject: bpf: Fix cgroup ref leak in cgroup_bpf_inherit on out-of-memory X-Git-Tag: v5.6~21^2~66^2~2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1d8006abaab4cb90f81add86e8d1bf9411add05a;p=linux-platform-drivers-x86.git bpf: Fix cgroup ref leak in cgroup_bpf_inherit on out-of-memory 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 Signed-off-by: Alexei Starovoitov Acked-by: Roman Gushchin Link: https://lore.kernel.org/bpf/20200309224017.1063297-1-andriin@fb.com --- diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index b2bc4c335bb1..4f1472409ef8 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -227,6 +227,9 @@ 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;