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authorDaniel Borkmann <daniel@iogearbox.net>2020-05-16 00:39:18 +0200
committerDaniel Borkmann <daniel@iogearbox.net>2020-05-16 00:48:02 +0200
commit2ec0616e870f0f2aa8353e0de057f0c2dc8d52d5 (patch)
treebdbfd9b5b041a9dfef6345cd072a25f2d9a421a7 /kernel/bpf
parentda07f52d3caf6c24c6dbffb5500f379d819e04bd (diff)
downloadlinux-2ec0616e870f0f2aa8353e0de057f0c2dc8d52d5.tar.gz
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 <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c3
1 files changed, 2 insertions, 1 deletions
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;
 		}