2023-02-22 08:13:48

by Yan Zhao

[permalink] [raw]
Subject: [PATCH] vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd

group->iommufd is not initialized for the iommufd_ctx_put()

[20018.331541] BUG: kernel NULL pointer dereference, address: 0000000000000000
[20018.377508] RIP: 0010:iommufd_ctx_put+0x5/0x10 [iommufd]
...
[20018.476483] Call Trace:
[20018.479214] <TASK>
[20018.481555] vfio_group_fops_unl_ioctl+0x506/0x690 [vfio]
[20018.487586] __x64_sys_ioctl+0x6a/0xb0
[20018.491773] ? trace_hardirqs_on+0xc5/0xe0
[20018.496347] do_syscall_64+0x67/0x90
[20018.500340] entry_SYSCALL_64_after_hwframe+0x4b/0xb5

Fixes: 9eefba8002c2 ("vfio: Move vfio group specific code into group.c")
Signed-off-by: Yan Zhao <[email protected]>
---
drivers/vfio/group.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 57ebe5e1a7e6..8649f85f3be4 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -137,7 +137,7 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,

ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
if (ret) {
- iommufd_ctx_put(group->iommufd);
+ iommufd_ctx_put(iommufd);
goto out_unlock;
}

--
2.17.1



2023-02-22 09:18:37

by Miko Larsson

[permalink] [raw]
Subject: Re: [PATCH] vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd

On Wed, 2023-02-22 at 15:49 +0800, Yan Zhao wrote:
> group->iommufd is not initialized for the iommufd_ctx_put()
>
> [20018.331541] BUG: kernel NULL pointer dereference, address:
> 0000000000000000
> [20018.377508] RIP: 0010:iommufd_ctx_put+0x5/0x10 [iommufd]
> ...
> [20018.476483] Call Trace:
> [20018.479214]  <TASK>
> [20018.481555]  vfio_group_fops_unl_ioctl+0x506/0x690 [vfio]
> [20018.487586]  __x64_sys_ioctl+0x6a/0xb0
> [20018.491773]  ? trace_hardirqs_on+0xc5/0xe0
> [20018.496347]  do_syscall_64+0x67/0x90
> [20018.500340]  entry_SYSCALL_64_after_hwframe+0x4b/0xb5
>
> Fixes: 9eefba8002c2 ("vfio: Move vfio group specific code into
> group.c")
> Signed-off-by: Yan Zhao <[email protected]>
> ---
>  drivers/vfio/group.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index 57ebe5e1a7e6..8649f85f3be4 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -137,7 +137,7 @@ static int vfio_group_ioctl_set_container(struct
> vfio_group *group,
>  
>                 ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
>                 if (ret) {
> -                       iommufd_ctx_put(group->iommufd);
> +                       iommufd_ctx_put(iommufd);
>                         goto out_unlock;
>                 }
>  

Might want to Cc this to the stable mailing list.
--
~miko

2023-02-22 09:25:29

by Yi Liu

[permalink] [raw]
Subject: RE: [PATCH] vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd

> From: Zhao, Yan Y <[email protected]>
> Sent: Wednesday, February 22, 2023 3:50 PM
> group->iommufd is not initialized for the iommufd_ctx_put()
>
> [20018.331541] BUG: kernel NULL pointer dereference, address:
> 0000000000000000
> [20018.377508] RIP: 0010:iommufd_ctx_put+0x5/0x10 [iommufd]
> ...
> [20018.476483] Call Trace:
> [20018.479214] <TASK>
> [20018.481555] vfio_group_fops_unl_ioctl+0x506/0x690 [vfio]
> [20018.487586] __x64_sys_ioctl+0x6a/0xb0
> [20018.491773] ? trace_hardirqs_on+0xc5/0xe0
> [20018.496347] do_syscall_64+0x67/0x90
> [20018.500340] entry_SYSCALL_64_after_hwframe+0x4b/0xb5
>
> Fixes: 9eefba8002c2 ("vfio: Move vfio group specific code into group.c")
> Signed-off-by: Yan Zhao <[email protected]>

Reviewed-by: Yi Liu <[email protected]>

> ---
> drivers/vfio/group.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index 57ebe5e1a7e6..8649f85f3be4 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -137,7 +137,7 @@ static int vfio_group_ioctl_set_container(struct
> vfio_group *group,
>
> ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
> if (ret) {
> - iommufd_ctx_put(group->iommufd);
> + iommufd_ctx_put(iommufd);
> goto out_unlock;
> }
>
> --
> 2.17.1


2023-02-22 12:58:38

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH] vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd

On Wed, Feb 22, 2023 at 03:49:38PM +0800, Yan Zhao wrote:
> group->iommufd is not initialized for the iommufd_ctx_put()
>
> [20018.331541] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [20018.377508] RIP: 0010:iommufd_ctx_put+0x5/0x10 [iommufd]
> ...
> [20018.476483] Call Trace:
> [20018.479214] <TASK>
> [20018.481555] vfio_group_fops_unl_ioctl+0x506/0x690 [vfio]
> [20018.487586] __x64_sys_ioctl+0x6a/0xb0
> [20018.491773] ? trace_hardirqs_on+0xc5/0xe0
> [20018.496347] do_syscall_64+0x67/0x90
> [20018.500340] entry_SYSCALL_64_after_hwframe+0x4b/0xb5
>
> Fixes: 9eefba8002c2 ("vfio: Move vfio group specific code into group.c")
> Signed-off-by: Yan Zhao <[email protected]>
> ---
> drivers/vfio/group.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jason Gunthorpe <[email protected]>

Jason

2023-02-22 18:00:33

by Alex Williamson

[permalink] [raw]
Subject: Re: [PATCH] vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd

On Wed, 22 Feb 2023 15:49:38 +0800
Yan Zhao <[email protected]> wrote:

> group->iommufd is not initialized for the iommufd_ctx_put()
>
> [20018.331541] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [20018.377508] RIP: 0010:iommufd_ctx_put+0x5/0x10 [iommufd]
> ...
> [20018.476483] Call Trace:
> [20018.479214] <TASK>
> [20018.481555] vfio_group_fops_unl_ioctl+0x506/0x690 [vfio]
> [20018.487586] __x64_sys_ioctl+0x6a/0xb0
> [20018.491773] ? trace_hardirqs_on+0xc5/0xe0
> [20018.496347] do_syscall_64+0x67/0x90
> [20018.500340] entry_SYSCALL_64_after_hwframe+0x4b/0xb5
>
> Fixes: 9eefba8002c2 ("vfio: Move vfio group specific code into group.c")
> Signed-off-by: Yan Zhao <[email protected]>
> ---
> drivers/vfio/group.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index 57ebe5e1a7e6..8649f85f3be4 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -137,7 +137,7 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
>
> ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
> if (ret) {
> - iommufd_ctx_put(group->iommufd);
> + iommufd_ctx_put(iommufd);
> goto out_unlock;
> }
>

Applied to vfio next branch for v6.3 and added a stable cc. Thanks,

Alex