From 62039c30c19dcab96621e074aeeb90da7100def7 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 9 Mar 2020 15:27:55 -0700 Subject: bpf: Initialize storage pointers to NULL to prevent freeing garbage pointer Local storage array isn't initialized, so if cgroup storage allocation fails for BPF_CGROUP_STORAGE_SHARED, error handling code will attempt to free uninitialized pointer for BPF_CGROUP_STORAGE_PERCPU storage type. Avoid this by always initializing storage pointers to NULLs. Fixes: 8bad74f9840f ("bpf: extend cgroup bpf core to allow multiple cgroup storage types") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200309222756.1018737-1-andriin@fb.com --- kernel/bpf/cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/bpf/cgroup.c') diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 9a500fadbef5..b2bc4c335bb1 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -302,8 +302,8 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)); struct list_head *progs = &cgrp->bpf.progs[type]; struct bpf_prog *old_prog = NULL; - struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE], - *old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {NULL}; + struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; + struct bpf_cgroup_storage *old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; struct bpf_prog_list *pl, *replace_pl = NULL; enum bpf_cgroup_storage_type stype; int err; -- cgit From 1d8006abaab4cb90f81add86e8d1bf9411add05a Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 9 Mar 2020 15:40:17 -0700 Subject: 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 --- kernel/bpf/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/bpf/cgroup.c') 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; -- cgit