Netdev List
 help / color / mirror / Atom feed
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


  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260604220904.1032145-2-ameryhung@gmail.com \
    --to=ameryhung@gmail.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=andrii@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=eddyz87@gmail.com \
    --cc=kernel-team@meta.com \
    --cc=martin.lau@kernel.org \
    --cc=memxor@gmail.com \
    --cc=mykyta.yatsenko5@gmail.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox