From 592ee43faf860c1f2c0a4c11838db6fdb974bb78 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Tue, 13 Nov 2018 09:29:26 +0000 Subject: [PATCH] bpf: fix null pointer dereference on pointer offload Pointer offload is being null checked however the following statement dereferences the potentially null pointer offload when assigning offload->dev_state. Fix this by only assigning it if offload is not null. Detected by CoverityScan, CID#1475437 ("Dereference after null check") Fixes: 00db12c3d141 ("bpf: call verifier_prep from its callback in struct bpf_offload_dev") Signed-off-by: Colin Ian King Acked-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov --- kernel/bpf/offload.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 52c5617..54cf2b9 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -130,9 +130,10 @@ int bpf_prog_offload_verifier_prep(struct bpf_prog *prog) down_read(&bpf_devs_lock); offload = prog->aux->offload; - if (offload) + if (offload) { ret = offload->offdev->ops->prepare(prog); - offload->dev_state = !ret; + offload->dev_state = !ret; + } up_read(&bpf_devs_lock); return ret; -- 2.7.4