2022-12-07 11:56:43

by Nanyong Sun

Subject: [PATCH] vdpa/vp_vdpa: fix kfree a wrong pointer in vp_vdpa_remove

From: Rong Wang <[email protected]>

In vp_vdpa_remove(), the code kfree(&vp_vdpa_mgtdev->mgtdev.id_table) uses
a reference of pointer as the argument of kfree, which is the wrong pointer
and then may hit crash like this:

Unable to handle kernel paging request at virtual address 00ffff003363e30c
Internal error: Oops: 96000004 [#1] SMP
Call trace:
rb_next+0x20/0x5c
ext4_readdir+0x494/0x5c4 [ext4]
iterate_dir+0x168/0x1b4
__se_sys_getdents64+0x68/0x170
__arm64_sys_getdents64+0x24/0x30
el0_svc_common.constprop.0+0x7c/0x1bc
do_el0_svc+0x2c/0x94
el0_svc+0x20/0x30
el0_sync_handler+0xb0/0xb4
el0_sync+0x160/0x180
Code: 54000220 f9400441 b4000161 aa0103e0 (f9400821)
SMP: stopping secondary CPUs
Starting crashdump kernel...

Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
Signed-off-by: Rong Wang <[email protected]>
Signed-off-by: Nanyong Sun <[email protected]>
---
drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index d448db0c4de3..8fe267ca3e76 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -647,7 +647,7 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
mdev = vp_vdpa_mgtdev->mdev;
vp_modern_remove(mdev);
vdpa_mgmtdev_unregister(&vp_vdpa_mgtdev->mgtdev);
- kfree(&vp_vdpa_mgtdev->mgtdev.id_table);
+ kfree(vp_vdpa_mgtdev->mgtdev.id_table);
kfree(mdev);
kfree(vp_vdpa_mgtdev);
}
--
2.25.1

2022-12-08 02:23:46

by Cindy Lu

Subject: Re: [PATCH] vdpa/vp_vdpa: fix kfree a wrong pointer in vp_vdpa_remove

On Wed, 7 Dec 2022 at 19:23, Nanyong Sun <[email protected]> wrote:
>
> From: Rong Wang <[email protected]>
>
> In vp_vdpa_remove(), the code kfree(&vp_vdpa_mgtdev->mgtdev.id_table) uses
> a reference of pointer as the argument of kfree, which is the wrong pointer
> and then may hit crash like this:
>
> Unable to handle kernel paging request at virtual address 00ffff003363e30c
> Internal error: Oops: 96000004 [#1] SMP
> Call trace:
> rb_next+0x20/0x5c
> ext4_readdir+0x494/0x5c4 [ext4]
> iterate_dir+0x168/0x1b4
> __se_sys_getdents64+0x68/0x170
> __arm64_sys_getdents64+0x24/0x30
> el0_svc_common.constprop.0+0x7c/0x1bc
> do_el0_svc+0x2c/0x94
> el0_svc+0x20/0x30
> el0_sync_handler+0xb0/0xb4
> el0_sync+0x160/0x180
> Code: 54000220 f9400441 b4000161 aa0103e0 (f9400821)
> SMP: stopping secondary CPUs
> Starting crashdump kernel...
>
> Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
> Signed-off-by: Rong Wang <[email protected]>
> Signed-off-by: Nanyong Sun <[email protected]>
> ---
> drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index d448db0c4de3..8fe267ca3e76 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -647,7 +647,7 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
> mdev = vp_vdpa_mgtdev->mdev;
> vp_modern_remove(mdev);
> vdpa_mgmtdev_unregister(&vp_vdpa_mgtdev->mgtdev);
> - kfree(&vp_vdpa_mgtdev->mgtdev.id_table);
> + kfree(vp_vdpa_mgtdev->mgtdev.id_table);
> kfree(mdev);
> kfree(vp_vdpa_mgtdev);
> }
> --
> 2.25.1
>
Reviewed-by: Cindy Lu <[email protected]>

2022-12-08 07:43:14

by Jason Wang

Subject: Re: [PATCH] vdpa/vp_vdpa: fix kfree a wrong pointer in vp_vdpa_remove

On Thu, Dec 8, 2022 at 10:05 AM Cindy Lu <[email protected]> wrote:
>
> On Wed, 7 Dec 2022 at 19:23, Nanyong Sun <[email protected]> wrote:
> >
> > From: Rong Wang <[email protected]>
> >
> > In vp_vdpa_remove(), the code kfree(&vp_vdpa_mgtdev->mgtdev.id_table) uses
> > a reference of pointer as the argument of kfree, which is the wrong pointer
> > and then may hit crash like this:
> >
> > Unable to handle kernel paging request at virtual address 00ffff003363e30c
> > Internal error: Oops: 96000004 [#1] SMP
> > Call trace:
> > rb_next+0x20/0x5c
> > ext4_readdir+0x494/0x5c4 [ext4]
> > iterate_dir+0x168/0x1b4
> > __se_sys_getdents64+0x68/0x170
> > __arm64_sys_getdents64+0x24/0x30
> > el0_svc_common.constprop.0+0x7c/0x1bc
> > do_el0_svc+0x2c/0x94
> > el0_svc+0x20/0x30
> > el0_sync_handler+0xb0/0xb4
> > el0_sync+0x160/0x180
> > Code: 54000220 f9400441 b4000161 aa0103e0 (f9400821)
> > SMP: stopping secondary CPUs
> > Starting crashdump kernel...
> >
> > Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
> > Signed-off-by: Rong Wang <[email protected]>
> > Signed-off-by: Nanyong Sun <[email protected]>
> > ---
> > drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > index d448db0c4de3..8fe267ca3e76 100644
> > --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > @@ -647,7 +647,7 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
> > mdev = vp_vdpa_mgtdev->mdev;
> > vp_modern_remove(mdev);
> > vdpa_mgmtdev_unregister(&vp_vdpa_mgtdev->mgtdev);
> > - kfree(&vp_vdpa_mgtdev->mgtdev.id_table);
> > + kfree(vp_vdpa_mgtdev->mgtdev.id_table);
> > kfree(mdev);
> > kfree(vp_vdpa_mgtdev);
> > }
> > --
> > 2.25.1
> >
> Reviewed-by: Cindy Lu <[email protected]>

Acked-by: Jason Wang <[email protected]>

Thanks

>