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From: KaFai Wan <kafai.wan@linux.dev>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	John Fastabend <john.fastabend@gmail.com>,
	Andrii Nakryiko <andrii@kernel.org>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Kumar Kartikeya Dwivedi <memxor@gmail.com>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Song Liu <song@kernel.org>,
	Yonghong Song <yonghong.song@linux.dev>,
	Jiri Olsa <jolsa@kernel.org>,
	Emil Tsalapatis <emil@etsalapatis.com>,
	Anton Protopopov <a.s.protopopov@gmail.com>,
	bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: KaFai Wan <kafai.wan@linux.dev>
Subject: [PATCH bpf 1/1] bpf: Fix insn_aux_data leak on verifier err_free_env path
Date: Wed, 24 Jun 2026 20:35:35 +0800	[thread overview]
Message-ID: <20260624123536.114757-1-kafai.wan@linux.dev> (raw)

When bpf_check() allocates env->insn_aux_data successfully but later
fails to allocate env->succ, it jumps directly to err_free_env.

The existing vfree(env->insn_aux_data) sits before the err_free_env
label, so that direct jump bypasses it and leaks insn_aux_data.

Move vfree(env->insn_aux_data) into err_free_env so all early and late
exit paths release it consistently.

Fixes: 2f69c5685427 ("bpf: make bpf_insn_successors to return a pointer")
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 21a365d436a5..3ccea8985946 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19994,13 +19994,13 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr,
 	if (!is_priv)
 		mutex_unlock(&bpf_verifier_lock);
 	bpf_clear_insn_aux_data(env, 0, env->prog->len);
-	vfree(env->insn_aux_data);
 err_free_env:
 	bpf_stack_liveness_free(env);
 	kvfree(env->cfg.insn_postorder);
 	kvfree(env->scc_info);
 	kvfree(env->succ);
 	kvfree(env->gotox_tmp_buf);
+	vfree(env->insn_aux_data);
 	kvfree(env);
 	return ret;
 }
-- 
2.43.0


             reply	other threads:[~2026-06-24 12:36 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-24 12:35 KaFai Wan [this message]
2026-06-24 14:40 ` [PATCH bpf 1/1] bpf: Fix insn_aux_data leak on verifier err_free_env path Anton Protopopov

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