mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: kbuild@lists.01.org, Liu Yi L <yi.l.liu@intel.com>
Cc: lkp@intel.com, kbuild-all@lists.01.org, linux-kernel@vger.kernel.org
Subject: [luxis1999-dev-iommu:iommufd-vfio-v5.16-rc1 21/32] drivers/iommufd/iommufd.c:163 iommufd_ioas_alloc() error: dereferencing freed memory 'ioas'
Date: Fri, 5 Nov 2021 12:39:47 +0300	[thread overview]
Message-ID: <202111050902.NYoMqWB7-lkp@intel.com> (raw)

tree:   https://github.com/luxis1999/dev-iommu iommufd-vfio-v5.16-rc1
head:   0c6c7bdb5b3f7d4c8e6b03d34a59ac6bf3d02539
commit: a13cbd0a0fca96a74a170239e2e88e68940331c3 [21/32] iommufd: Add IOMMU_IOAS_ALLOC/FREE
config: x86_64-randconfig-m001-20211105 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/iommufd/iommufd.c:163 iommufd_ioas_alloc() error: dereferencing freed memory 'ioas'

vim +/ioas +163 drivers/iommufd/iommufd.c

a13cbd0a0fca96 Liu Yi L 2021-10-31  126  static int iommufd_ioas_alloc(struct iommufd_ctx *ictx, unsigned long arg)
a13cbd0a0fca96 Liu Yi L 2021-10-31  127  {
a13cbd0a0fca96 Liu Yi L 2021-10-31  128  	struct iommu_ioas_alloc req;
a13cbd0a0fca96 Liu Yi L 2021-10-31  129  	struct iommufd_ioas *ioas;
a13cbd0a0fca96 Liu Yi L 2021-10-31  130  	unsigned long minsz;
a13cbd0a0fca96 Liu Yi L 2021-10-31  131  	int ret;
a13cbd0a0fca96 Liu Yi L 2021-10-31  132  
a13cbd0a0fca96 Liu Yi L 2021-10-31  133  	minsz = offsetofend(struct iommu_ioas_alloc, addr_width);
a13cbd0a0fca96 Liu Yi L 2021-10-31  134  
a13cbd0a0fca96 Liu Yi L 2021-10-31  135  	if (copy_from_user(&req, (void __user *)arg, minsz))
a13cbd0a0fca96 Liu Yi L 2021-10-31  136  		return -EFAULT;
a13cbd0a0fca96 Liu Yi L 2021-10-31  137  
a13cbd0a0fca96 Liu Yi L 2021-10-31  138  	if (req.argsz < minsz || !req.addr_width ||
a13cbd0a0fca96 Liu Yi L 2021-10-31  139  	    req.flags != IOMMU_IOAS_ENFORCE_SNOOP ||
a13cbd0a0fca96 Liu Yi L 2021-10-31  140  	    req.type != IOMMU_IOAS_TYPE_KERNEL_TYPE1V2)
a13cbd0a0fca96 Liu Yi L 2021-10-31  141  		return -EINVAL;
a13cbd0a0fca96 Liu Yi L 2021-10-31  142  
a13cbd0a0fca96 Liu Yi L 2021-10-31  143  	ioas = kzalloc(sizeof(*ioas), GFP_KERNEL);
a13cbd0a0fca96 Liu Yi L 2021-10-31  144  	if (!ioas)
a13cbd0a0fca96 Liu Yi L 2021-10-31  145  		return -ENOMEM;
a13cbd0a0fca96 Liu Yi L 2021-10-31  146  
a13cbd0a0fca96 Liu Yi L 2021-10-31  147  	/* only supports kernel managed I/O page table so far */
a13cbd0a0fca96 Liu Yi L 2021-10-31  148  	ioas->type = IOMMU_IOAS_TYPE_KERNEL_TYPE1V2;
a13cbd0a0fca96 Liu Yi L 2021-10-31  149  	ioas->addr_width = req.addr_width;
a13cbd0a0fca96 Liu Yi L 2021-10-31  150  	/* only supports enforce snoop today */
a13cbd0a0fca96 Liu Yi L 2021-10-31  151  	ioas->enforce_snoop = true;
a13cbd0a0fca96 Liu Yi L 2021-10-31  152  	ioas->ictx = ictx;
a13cbd0a0fca96 Liu Yi L 2021-10-31  153  
a13cbd0a0fca96 Liu Yi L 2021-10-31  154  	refcount_set(&ioas->refs, 1);
a13cbd0a0fca96 Liu Yi L 2021-10-31  155  
a13cbd0a0fca96 Liu Yi L 2021-10-31  156  	ret = xa_alloc(&ictx->ioas_xa, &ioas->ioas_id, ioas,
a13cbd0a0fca96 Liu Yi L 2021-10-31  157  		       xa_limit_32b, GFP_KERNEL);
a13cbd0a0fca96 Liu Yi L 2021-10-31  158  	if (ret)
a13cbd0a0fca96 Liu Yi L 2021-10-31  159  		kfree(ioas);

Needs to return -ENOMEM here.

a13cbd0a0fca96 Liu Yi L 2021-10-31  160  
a13cbd0a0fca96 Liu Yi L 2021-10-31  161  	if (copy_to_user((void __user *)arg + minsz,
a13cbd0a0fca96 Liu Yi L 2021-10-31  162  			 &ioas->ioas_id, sizeof(ioas->ioas_id))) {
                                                                  ^^^^^^^^^^^^^
Already freed.

a13cbd0a0fca96 Liu Yi L 2021-10-31 @163  		xa_erase(&ictx->ioas_xa, ioas->ioas_id);
a13cbd0a0fca96 Liu Yi L 2021-10-31  164  		kfree(ioas);
a13cbd0a0fca96 Liu Yi L 2021-10-31  165  		ret = -EFAULT;
a13cbd0a0fca96 Liu Yi L 2021-10-31  166  	}
a13cbd0a0fca96 Liu Yi L 2021-10-31  167  
a13cbd0a0fca96 Liu Yi L 2021-10-31  168  	return ret;
a13cbd0a0fca96 Liu Yi L 2021-10-31  169  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org


                 reply	other threads:[~2021-11-05  9:40 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=202111050902.NYoMqWB7-lkp@intel.com \
    --to=dan.carpenter@oracle.com \
    --cc=kbuild-all@lists.01.org \
    --cc=kbuild@lists.01.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lkp@intel.com \
    --cc=yi.l.liu@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

all inboxes | Powered by JetHome®