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

Jason Gunthorpe
2023-02-22T12:58:38Z

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 <yan.y.zhao@intel.com>
> ---
> drivers/vfio/group.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason