linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Wan Jiabing <wanjiabing@vivo.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Yi Liu <yi.l.liu@intel.com>, Kevin Tian <kevin.tian@intel.com>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Wan Jiabing <wanjiabing@vivo.com>
Subject: [PATCH] kvm/vfio: Fix potential deadlock problem in vfio
Date: Tue, 17 May 2022 10:34:41 +0800	[thread overview]
Message-ID: <20220517023441.4258-1-wanjiabing@vivo.com> (raw)

Fix following coccicheck warning:
./virt/kvm/vfio.c:258:1-7: preceding lock on line 236

If kvm_vfio_file_iommu_group() failed, code would goto err_fdput with
mutex_lock acquired and then return ret. It might cause potential
deadlock. Move mutex_unlock bellow err_fdput tag to fix it. 

Fixes: d55d9e7a45721 ("kvm/vfio: Store the struct file in the kvm_vfio_group")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
---
 virt/kvm/vfio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 8f9f7fffb96a..ce1b01d02c51 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -252,8 +252,8 @@ static int kvm_vfio_group_set_spapr_tce(struct kvm_device *dev,
 		break;
 	}
 
-	mutex_unlock(&kv->lock);
 err_fdput:
+	mutex_unlock(&kv->lock);
 	fdput(f);
 	return ret;
 }
-- 
2.36.1


             reply	other threads:[~2022-05-17  2:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-17  2:34 Wan Jiabing [this message]
2022-05-17 18:58 ` [PATCH] kvm/vfio: Fix potential deadlock problem in vfio Jason Gunthorpe
2022-05-18 17:51 ` Alex Williamson

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=20220517023441.4258-1-wanjiabing@vivo.com \
    --to=wanjiabing@vivo.com \
    --cc=alex.williamson@redhat.com \
    --cc=jgg@ziepe.ca \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.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;
as well as URLs for NNTP newsgroup(s).