From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
<martin.lau@kernel.org>
Cc: <andrii@kernel.org>, <kernel-team@meta.com>,
Eduard Zingerman <eddyz87@gmail.com>
Subject: [PATCH v3 bpf-next 07/10] bpf: enforce precision of R0 on program/async callback return
Date: Wed, 29 Nov 2023 16:04:03 -0800 [thread overview]
Message-ID: <20231130000406.480870-8-andrii@kernel.org> (raw)
In-Reply-To: <20231130000406.480870-1-andrii@kernel.org>
Given we enforce a valid range for program and async callback return
value, we must mark R0 as precise to avoid incorrect state pruning.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
kernel/bpf/verifier.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c54944af1bcc..2cd150d6d141 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -15138,6 +15138,10 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char
return -EINVAL;
}
+ err = mark_chain_precision(env, regno);
+ if (err)
+ return err;
+
if (!retval_range_within(range, reg)) {
verbose_invalid_scalar(env, reg, range, exit_ctx, reg_name);
if (!is_subprog &&
--
2.34.1
next prev parent reply other threads:[~2023-11-30 0:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-30 0:03 [PATCH v3 bpf-next 00/10] BPF verifier retval logic fixes Andrii Nakryiko
2023-11-30 0:03 ` [PATCH v3 bpf-next 01/10] bpf: provide correct register name for exception callback retval check Andrii Nakryiko
2023-11-30 5:41 ` Shung-Hsi Yu
2023-11-30 0:03 ` [PATCH v3 bpf-next 02/10] bpf: enforce precision of R0 on callback return Andrii Nakryiko
2023-11-30 5:43 ` Shung-Hsi Yu
2023-11-30 0:03 ` [PATCH v3 bpf-next 03/10] bpf: enforce exact retval range on subprog/callback exit Andrii Nakryiko
2023-11-30 5:49 ` Shung-Hsi Yu
2023-11-30 0:04 ` [PATCH v3 bpf-next 04/10] selftests/bpf: add selftest validating callback result is enforced Andrii Nakryiko
2023-11-30 5:52 ` Shung-Hsi Yu
2023-11-30 0:04 ` [PATCH v3 bpf-next 05/10] bpf: enforce precise retval range on program exit Andrii Nakryiko
2023-11-30 5:54 ` Shung-Hsi Yu
2023-11-30 0:04 ` [PATCH v3 bpf-next 06/10] bpf: unify async callback and program retval checks Andrii Nakryiko
2023-11-30 5:56 ` Shung-Hsi Yu
2023-11-30 0:04 ` Andrii Nakryiko [this message]
2023-11-30 6:33 ` [PATCH v3 bpf-next 07/10] bpf: enforce precision of R0 on program/async callback return Shung-Hsi Yu
2023-11-30 6:41 ` Andrii Nakryiko
2023-11-30 0:04 ` [PATCH v3 bpf-next 08/10] selftests/bpf: validate async callback return value check correctness Andrii Nakryiko
2023-11-30 0:04 ` [PATCH v3 bpf-next 09/10] selftests/bpf: adjust global_func15 test to validate prog exit precision Andrii Nakryiko
2023-11-30 0:04 ` [PATCH v3 bpf-next 10/10] bpf: simplify tnum output if a fully known constant Andrii Nakryiko
2023-11-30 6:34 ` Shung-Hsi Yu
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