On Sun, Sep 5, 2021 at 6:58 PM Len Baker <len.baker@xxxxxxx> wrote: > > As noted in the "Deprecated Interfaces, Language Features, Attributes, > and Conventions" documentation [1], size calculations (especially > multiplication) should not be performed in memory allocator (or similar) > function arguments due to the risk of them overflowing. This could lead > to values wrapping around and a smaller allocation being made than the > caller was expecting. Using those allocations could lead to linear > overflows of heap memory and other misbehaviors. > > So, use the struct_size() helper to do the arithmetic instead of the > argument "size + size * count" in the kzalloc() function. Makes sense Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > [1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments > > Signed-off-by: Len Baker <len.baker@xxxxxxx> > --- > drivers/tty/serial/8250/8250_pci.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c > index a808c283883e..b97ade35d4a3 100644 > --- a/drivers/tty/serial/8250/8250_pci.c > +++ b/drivers/tty/serial/8250/8250_pci.c > @@ -3981,9 +3981,7 @@ pciserial_init_ports(struct pci_dev *dev, const struct pciserial_board *board) > nr_ports = rc; > } > > - priv = kzalloc(sizeof(struct serial_private) + > - sizeof(unsigned int) * nr_ports, > - GFP_KERNEL); > + priv = kzalloc(struct_size(priv, line, nr_ports), GFP_KERNEL); > if (!priv) { > priv = ERR_PTR(-ENOMEM); > goto err_deinit; > -- > 2.25.1 > -- With Best Regards, Andy Shevchenko
