From 6712cc9c22117a8af9f3df272b4a44fd2e4201cd Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <stephen@networkplumber.org>
Date: Mon, 20 Aug 2018 21:16:40 +0000
Subject: [PATCH] vmbus: don't return values for uninitalized channels
Git-commit: 6712cc9c22117a8af9f3df272b4a44fd2e4201cd
Patch-mainline: v4.19-rc4
References: bsc#1051510, bsc#1107207
For unsupported device types, the vmbus channel ringbuffer is never
initialized, and therefore reading the sysfs files will return garbage
or cause a kernel OOPS.
Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org> # 4.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Olaf Hering <ohering@suse.de>
---
drivers/hv/vmbus_drv.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index b1b548a21f91..c71cc857b649 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1291,6 +1291,9 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
if (!attribute->show)
return -EIO;
+ if (chan->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
+
return attribute->show(chan, buf);
}
--
2.19.0