| Message ID | 20220517023441.4258-1-wanjiabing@vivo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kvm/vfio: Fix potential deadlock problem in vfio | expand |
On Tue, May 17, 2022 at 10:34:41AM +0800, Wan Jiabing wrote: > 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(-) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Thanks, Jason
On Tue, 17 May 2022 10:34:41 +0800 Wan Jiabing <wanjiabing@vivo.com> wrote: > 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; > } Applied to vfio next branch for v5.19. Thanks! Alex
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; }
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(-)