Re: [PULL 07/11] vfio: Fix null pointer dereference bug in vfio_bars_finalize()

[Michael Tokarev]

10.07.2023 10:48, Cédric Le Goater пишет:
> From: Avihai Horon <avihaih@nvidia.com>
>
> vfio_realize() has the following flow:
> 1. vfio_bars_prepare() -- sets VFIOBAR->size.
> 2. msix_early_setup().
> 3. vfio_bars_register() -- allocates VFIOBAR->mr.
>
> After vfio_bars_prepare() is called msix_early_setup() can fail. If it
> does fail, vfio_bars_register() is never called and VFIOBAR->mr is not
> allocated.
>
> In this case, vfio_bars_finalize() is called as part of the error flow
> to free the bars' resources. However, vfio_bars_finalize() calls
> object_unparent() for VFIOBAR->mr after checking only VFIOBAR->size, and
> thus we get a null pointer dereference.
>
> Fix it by checking VFIOBAR->mr in vfio_bars_finalize().
>
> Fixes: 89d5202edc50 ("vfio/pci: Allow relocating MSI-X MMIO")
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>

It looks like it's a -stable material too. Queued this one.
If it shouldn't go to stable, please let me know.

Thanks,

/mjt