From: Christoph Hellwig <hch@lst.de>
To: kernel test robot <lkp@intel.com>
Cc: Christoph Hellwig <hch@lst.de>,
kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: drivers/usb/core/devio.c:1155 do_proc_control() error: copy_from_user() 'tbuf' too small (4096 vs 8192)
Date: Mon, 10 Aug 2020 14:12:23 +0200 [thread overview]
Message-ID: <20200810121222.GA18639@lst.de> (raw)
In-Reply-To: <202008081337.Z6BAxT0d%lkp@intel.com>
As far as I can tell the warning is valid as we copy a user controlled
amount into a fixed sized buffer. But this an old condition not actually
created by this commit..
On Sat, Aug 08, 2020 at 01:26:39PM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 049eb096da48db0421dd5e358b9b082a1a8a2025
> commit: c17536d0abde2fd24afca542e3bb73b45a299633 usb: usbfs: stop using compat_alloc_user_space
> date: 2 weeks ago
> config: nds32-randconfig-m031-20200808 (attached as .config)
> compiler: nds32le-linux-gcc (GCC) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> smatch warnings:
> drivers/usb/core/devio.c:1155 do_proc_control() error: copy_from_user() 'tbuf' too small (4096 vs 8192)
>
> vim +/tbuf +1155 drivers/usb/core/devio.c
>
> 1104
> 1105 static int do_proc_control(struct usb_dev_state *ps,
> 1106 struct usbdevfs_ctrltransfer *ctrl)
> 1107 {
> 1108 struct usb_device *dev = ps->dev;
> 1109 unsigned int tmo;
> 1110 unsigned char *tbuf;
> 1111 unsigned wLength;
> 1112 int i, pipe, ret;
> 1113
> 1114 ret = check_ctrlrecip(ps, ctrl->bRequestType, ctrl->bRequest,
> 1115 ctrl->wIndex);
> 1116 if (ret)
> 1117 return ret;
> 1118 wLength = ctrl->wLength; /* To suppress 64k PAGE_SIZE warning */
> 1119 if (wLength > PAGE_SIZE)
> 1120 return -EINVAL;
> 1121 ret = usbfs_increase_memory_usage(PAGE_SIZE + sizeof(struct urb) +
> 1122 sizeof(struct usb_ctrlrequest));
> 1123 if (ret)
> 1124 return ret;
> 1125 tbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
> 1126 if (!tbuf) {
> 1127 ret = -ENOMEM;
> 1128 goto done;
> 1129 }
> 1130 tmo = ctrl->timeout;
> 1131 snoop(&dev->dev, "control urb: bRequestType=%02x "
> 1132 "bRequest=%02x wValue=%04x "
> 1133 "wIndex=%04x wLength=%04x\n",
> 1134 ctrl->bRequestType, ctrl->bRequest, ctrl->wValue,
> 1135 ctrl->wIndex, ctrl->wLength);
> 1136 if (ctrl->bRequestType & 0x80) {
> 1137 pipe = usb_rcvctrlpipe(dev, 0);
> 1138 snoop_urb(dev, NULL, pipe, ctrl->wLength, tmo, SUBMIT, NULL, 0);
> 1139
> 1140 usb_unlock_device(dev);
> 1141 i = usb_control_msg(dev, pipe, ctrl->bRequest,
> 1142 ctrl->bRequestType, ctrl->wValue, ctrl->wIndex,
> 1143 tbuf, ctrl->wLength, tmo);
> 1144 usb_lock_device(dev);
> 1145 snoop_urb(dev, NULL, pipe, max(i, 0), min(i, 0), COMPLETE,
> 1146 tbuf, max(i, 0));
> 1147 if ((i > 0) && ctrl->wLength) {
> 1148 if (copy_to_user(ctrl->data, tbuf, i)) {
> 1149 ret = -EFAULT;
> 1150 goto done;
> 1151 }
> 1152 }
> 1153 } else {
> 1154 if (ctrl->wLength) {
> > 1155 if (copy_from_user(tbuf, ctrl->data, ctrl->wLength)) {
> 1156 ret = -EFAULT;
> 1157 goto done;
> 1158 }
> 1159 }
> 1160 pipe = usb_sndctrlpipe(dev, 0);
> 1161 snoop_urb(dev, NULL, pipe, ctrl->wLength, tmo, SUBMIT,
> 1162 tbuf, ctrl->wLength);
> 1163
> 1164 usb_unlock_device(dev);
> 1165 i = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), ctrl->bRequest,
> 1166 ctrl->bRequestType, ctrl->wValue, ctrl->wIndex,
> 1167 tbuf, ctrl->wLength, tmo);
> 1168 usb_lock_device(dev);
> 1169 snoop_urb(dev, NULL, pipe, max(i, 0), min(i, 0), COMPLETE, NULL, 0);
> 1170 }
> 1171 if (i < 0 && i != -EPIPE) {
> 1172 dev_printk(KERN_DEBUG, &dev->dev, "usbfs: USBDEVFS_CONTROL "
> 1173 "failed cmd %s rqt %u rq %u len %u ret %d\n",
> 1174 current->comm, ctrl->bRequestType, ctrl->bRequest,
> 1175 ctrl->wLength, i);
> 1176 }
> 1177 ret = i;
> 1178 done:
> 1179 free_page((unsigned long) tbuf);
> 1180 usbfs_decrease_memory_usage(PAGE_SIZE + sizeof(struct urb) +
> 1181 sizeof(struct usb_ctrlrequest));
> 1182 return ret;
> 1183 }
> 1184
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
---end quoted text---
next prev parent reply other threads:[~2020-08-10 12:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-08 5:26 drivers/usb/core/devio.c:1155 do_proc_control() error: copy_from_user() 'tbuf' too small (4096 vs 8192) kernel test robot
2020-08-10 12:12 ` Christoph Hellwig [this message]
2020-08-10 12:14 ` Christoph Hellwig
2020-08-10 13:34 ` Dan Carpenter
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=20200810121222.GA18639@lst.de \
--to=hch@lst.de \
--cc=gregkh@linuxfoundation.org \
--cc=kbuild-all@lists.01.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.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