Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Li Zhong <floridsleeves@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     peterz@infradead.org, jpoimboe@kernel.org, jbaron@akamai.com,
        rostedt@goodmis.org, ardb@kernel.org, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, Li Zhong <floridsleeves@gmail.com>
Subject: [PATCH v1] arch/x86/kernel: check the return value of insn_decode_kernel()
Date:   Fri,  2 Sep 2022 00:47:06 -0700
Message-Id: <20220902074706.2211252-1-floridsleeves@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

insn_decode() could fail and the insn.length could be invalid. So we
need to check the return value first.

Signed-off-by: Li Zhong <floridsleeves@gmail.com>
---
 arch/x86/kernel/jump_label.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index f5b8ef02d172..3ecaf0cc71d0 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -20,9 +20,10 @@
 int arch_jump_entry_size(struct jump_entry *entry)
 {
 	struct insn insn = {};
+	int ret;
 
-	insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
-	BUG_ON(insn.length != 2 && insn.length != 5);
+	ret = insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
+	BUG_ON(ret < 0 || insn.length != 2 && insn.length != 5);
 
 	return insn.length;
 }
-- 
2.25.1