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@xxxxxxxxxx> > --- 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