From 2ec0616e870f0f2aa8353e0de057f0c2dc8d52d5 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 16 May 2020 00:39:18 +0200 Subject: bpf: Fix check_return_code to only allow [0,1] in trace_iter progs As per 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program") we only allow a range of [0,1] for return codes. Therefore BPF_TRACE_ITER relies on the default tnum_range(0, 1) which is set in range var. On recent merge of net into net-next commit e92888c72fbd ("bpf: Enforce returning 0 for fentry/fexit progs") got pulled in and caused a merge conflict with the changes from 15d83c4d7cef. The resolution had a snall hiccup in that it removed the [0,1] range restriction again so that BPF_TRACE_ITER would have no enforcement. Fix it by adding it back. Fixes: da07f52d3caf ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 25b14ee0e26d..9c7d67d65d8c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7120,10 +7120,11 @@ static int check_return_code(struct bpf_verifier_env *env) case BPF_TRACE_FEXIT: range = tnum_const(0); break; - case BPF_TRACE_ITER: case BPF_TRACE_RAW_TP: case BPF_MODIFY_RETURN: return 0; + case BPF_TRACE_ITER: + break; default: return -ENOTSUPP; } -- cgit v1.2.3-59-g8ed1b