From: Jiri Olsa <jolsa@kernel.org>
Date: Fri, 8 Nov 2024 13:45:32 +0000 (+0100)
Subject: bpf: Allow return values 0 and 1 for kprobe session
X-Git-Tag: v6.11.11~475
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=20a1ee9fcce7bc1cbcb8b45205325d966ed9432b;p=thirdparty%2Fkernel%2Fstable.git

bpf: Allow return values 0 and 1 for kprobe session

[ Upstream commit 17c4b65a24938c6dd79496cce5df15f70d9c253c ]

The kprobe session program can return only 0 or 1,
instruct verifier to check for that.

Fixes: 535a3692ba72 ("bpf: Add support for kprobe session attach")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-2-jolsa@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b34a358c75e0f..61c3896087b2c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -15798,6 +15798,15 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char
 			return -ENOTSUPP;
 		}
 		break;
+	case BPF_PROG_TYPE_KPROBE:
+		switch (env->prog->expected_attach_type) {
+		case BPF_TRACE_KPROBE_SESSION:
+			range = retval_range(0, 1);
+			break;
+		default:
+			return 0;
+		}
+		break;
 	case BPF_PROG_TYPE_SK_LOOKUP:
 		range = retval_range(SK_DROP, SK_PASS);
 		break;