linux-kernel - [PATCH 4/5] Drivers: hv: make sure that 'struct vmbus_channel_message

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200401103816.1406642-1-vkuznets@redhat.com>
Date:   Wed,  1 Apr 2020 12:38:15 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     linux-hyperv@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, Wei Liu <wei.liu@...nel.org>,
        Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        Michael Kelley <mikelley@...rosoft.com>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "Andrea Parri (Microsoft)" <parri.andrea@...il.com>
Subject: [PATCH 4/5] Drivers: hv: make sure that 'struct vmbus_channel_message_header' compiles correctly

Strictly speaking, compiler is free to use something different from 'u32'
for 'enum vmbus_channel_message_type' (e.g. char) but it doesn't happen in
real life, just add a BUILD_BUG_ON() guardian.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 drivers/hv/vmbus_drv.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 0f7bbf952d89..d684cbee7ae6 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1023,6 +1023,13 @@ void vmbus_on_msg_dpc(unsigned long data)
 	struct onmessage_work_context *ctx;
 	u32 message_type = msg->header.message_type;
 
+	/*
+	 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
+	 * it is being used in 'struct vmbus_channel_message_header' definition
+	 * which is supposed to match hypervisor ABI.
+	 */
+	BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
+
 	if (message_type == HVMSG_NONE)
 		/* no msg */
 		return;
-- 
2.25.1