From: Amery Hung <ameryhung@gmail.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, alexei.starovoitov@gmail.com,
andrii@kernel.org, daniel@iogearbox.net, eddyz87@gmail.com,
memxor@gmail.com, martin.lau@kernel.org,
mykyta.yatsenko5@gmail.com, ameryhung@gmail.com,
kernel-team@meta.com
Subject: [PATCH bpf-next v1 1/3] bpf: Fix dead error check on acquire_reference() in check_kfunc_call
Date: Thu, 4 Jun 2026 15:09:02 -0700 [thread overview]
Message-ID: <20260604220904.1032145-2-ameryhung@gmail.com> (raw)
In-Reply-To: <20260604220904.1032145-1-ameryhung@gmail.com>
acquire_reference() returns a signed int that may be a negative errno
but was converted to unsigned, which makes the subsequent error check
deadcode. Fix it by declaring 'id' as int so the error path is taken
correctly.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
---
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 8ed484cb1a8a..6446db9628ae 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -12817,9 +12817,10 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
struct bpf_kfunc_call_arg_meta meta;
struct bpf_insn_aux_data *insn_aux;
int err, insn_idx = *insn_idx_p;
- u32 i, nargs, ptr_type_id, id;
const struct btf_param *args;
+ u32 i, nargs, ptr_type_id;
struct btf *desc_btf;
+ int id;
/* skip for now, but return error when we find this in fixup_kfunc_call */
if (!insn->imm)
--
2.53.0-Meta
next prev parent reply other threads:[~2026-06-04 22:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-04 22:09 [PATCH bpf-next v1 0/3] Object relationship refactor followup Amery Hung
2026-06-04 22:09 ` Amery Hung [this message]
2026-06-04 22:43 ` [PATCH bpf-next v1 1/3] bpf: Fix dead error check on acquire_reference() in check_kfunc_call bot+bpf-ci
2026-06-04 23:16 ` Eduard Zingerman
2026-06-04 22:09 ` [PATCH bpf-next v1 2/3] bpf: Compare parent_id in refsafe() for REF_TYPE_PTR Amery Hung
2026-06-04 22:59 ` bot+bpf-ci
2026-06-04 23:21 ` Eduard Zingerman
2026-06-04 23:27 ` Amery Hung
2026-06-04 22:09 ` [PATCH bpf-next v1 3/3] selftests/bpf: Use bpf_dynptr_slice() to read file dynptr in leak test Amery Hung
2026-06-04 23:22 ` Eduard Zingerman
2026-06-04 22:14 ` [PATCH bpf-next v1 0/3] Object relationship refactor followup Kumar Kartikeya Dwivedi
2026-06-04 23:20 ` Amery Hung
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