From: Greg KH <gregkh@linuxfoundation.org>
To: Dongliang Mu <mudongliangabcd@gmail.com>
Cc: davem@davemloft.net, helmut.schaa@googlemail.com,
kvalo@codeaurora.org, linux-kernel@vger.kernel.org,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
sgruszka@redhat.com
Subject: Re: [PATCH] rt2x00: reset reg earlier in rt2500usb_register_read
Date: Thu, 21 Jan 2021 10:49:56 +0100 [thread overview]
Message-ID: <YAlORNKQ4y7bzYeZ@kroah.com> (raw)
In-Reply-To: <20210121092026.3261412-1-mudongliangabcd@gmail.com>
On Thu, Jan 21, 2021 at 05:20:26PM +0800, Dongliang Mu wrote:
> In the function rt2500usb_register_read(_lock), reg is uninitialized
> in some situation. Then KMSAN reports uninit-value at its first memory
> access. To fix this issue, add one reg initialization in the function
> rt2500usb_register_read and rt2500usb_register_read_lock
>
> BUG: KMSAN: uninit-value in rt2500usb_init_eeprom rt2500usb.c:1443 [inline]
> BUG: KMSAN: uninit-value in rt2500usb_probe_hw+0xb5e/0x22a0 rt2500usb.c:1757
> CPU: 0 PID: 3369 Comm: kworker/0:2 Not tainted 5.3.0-rc7+ #0
> Hardware name: Google Compute Engine
> Workqueue: usb_hub_wq hub_event
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x191/0x1f0 lib/dump_stack.c:113
> kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109
> __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294
> rt2500usb_init_eeprom wireless/ralink/rt2x00/rt2500usb.c:1443 [inline]
> rt2500usb_probe_hw+0xb5e/0x22a0 wireless/ralink/rt2x00/rt2500usb.c:1757
> rt2x00lib_probe_dev+0xba9/0x3260 wireless/ralink/rt2x00/rt2x00dev.c:1427
> rt2x00usb_probe+0x7ae/0xf60 wireless/ralink/rt2x00/rt2x00usb.c:842
> rt2500usb_probe+0x50/0x60 wireless/ralink/rt2x00/rt2500usb.c:1966
> ......
>
> Local variable description: ----reg.i.i@rt2500usb_probe_hw
> Variable was created at:
> rt2500usb_register_read wireless/ralink/rt2x00/rt2500usb.c:51 [inline]
> rt2500usb_init_eeprom wireless/ralink/rt2x00/rt2500usb.c:1440 [inline]
> rt2500usb_probe_hw+0x774/0x22a0 wireless/ralink/rt2x00/rt2500usb.c:1757
> rt2x00lib_probe_dev+0xba9/0x3260 wireless/ralink/rt2x00/rt2x00dev.c:1427
>
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
> drivers/net/wireless/ralink/rt2x00/rt2500usb.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
> index fce05fc88aaf..f6c93a25b18c 100644
> --- a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
> +++ b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c
> @@ -48,6 +48,7 @@ static u16 rt2500usb_register_read(struct rt2x00_dev *rt2x00dev,
> const unsigned int offset)
> {
> __le16 reg;
> + memset(®, 0, sizeof(reg));
As was pointed out, just set reg = 0 on the line above please.
> rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_READ,
> USB_VENDOR_REQUEST_IN, offset,
> ®, sizeof(reg));
Are you sure this is valid to call this function with a variable on the
stack like this? How did you test this change?
thanks,
greg k-h
next prev parent reply other threads:[~2021-01-21 9:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 9:20 [PATCH] rt2x00: reset reg earlier in rt2500usb_register_read Dongliang Mu
2021-01-21 9:49 ` Greg KH [this message]
2021-01-21 10:59 ` 慕冬亮
2021-01-21 11:20 ` Greg KH
2021-01-21 11:21 ` Greg KH
2021-01-21 11:25 ` 慕冬亮
2021-01-21 10:52 Dongliang Mu
2021-01-21 11:19 ` Greg KH
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=YAlORNKQ4y7bzYeZ@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=davem@davemloft.net \
--cc=helmut.schaa@googlemail.com \
--cc=kvalo@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=mudongliangabcd@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=sgruszka@redhat.com \
/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;
as well as URLs for NNTP newsgroup(s).