Messages in this thread | | | Date | Tue, 5 Jul 2022 15:06:49 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] vfio: hisi_acc_vfio_pci: fix integer overflow check in hisi_acc_vf_resume_write() |
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On Tue, Jul 05, 2022 at 12:05:28PM +0300, Dan Carpenter wrote: > The casting on this makes the integer overflow check slightly wrong. > "len" is an unsigned long. "*pos" and "requested_length" are signed > long longs. Imagine "len" is ULONG_MAX and "*pos" is 2. > "ULONG_MAX + 2 = 1".
I wonder if this can happen, len is a kernel controlled value bounded by a memory allocation..
> Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > ---
This code was copy and pasted from drivers/vfio/pci/mlx5/main.c, so it should be fixed too
> It is strange that we are doing: > > pos = &filp->f_pos; > > instead of using the passed in value of pos.
IIRC the way we have the struct file configured the pos argument is NULL.
Jason
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