Hello Jordy, On Tue, 1 Feb 2022 at 02:09, John Stultz <john.stultz@xxxxxxxxxx> wrote: > > On Sat, Jan 29, 2022 at 7:06 AM Jordy Zomer <jordy@pwning.systems> wrote: > > > > It appears like nr could be a Spectre v1 gadget as it's supplied by a > > user and used as an array index. Prevent the contents > > of kernel memory from being leaked to userspace via speculative > > execution by using array_index_nospec. > > > > Signed-off-by: Jordy Zomer <jordy@pwning.systems> Thanks very much for your patch; I've pushed it to drm-misc-fixes, so we should see it in mainline soon. > > --- > > drivers/dma-buf/dma-heap.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c > > index 56bf5ad01ad5..8f5848aa144f 100644 > > --- a/drivers/dma-buf/dma-heap.c > > +++ b/drivers/dma-buf/dma-heap.c > > @@ -14,6 +14,7 @@ > > #include <linux/xarray.h> > > #include <linux/list.h> > > #include <linux/slab.h> > > +#include <linux/nospec.h> > > #include <linux/uaccess.h> > > #include <linux/syscalls.h> > > #include <linux/dma-heap.h> > > @@ -135,6 +136,7 @@ static long dma_heap_ioctl(struct file *file, unsigned int ucmd, > > if (nr >= ARRAY_SIZE(dma_heap_ioctl_cmds)) > > return -EINVAL; > > > > + nr = array_index_nospec(nr, ARRAY_SIZE(dma_heap_ioctl_cmds)); > > /* Get the kernel ioctl cmd that matches */ > > kcmd = dma_heap_ioctl_cmds[nr]; > > Thanks for submitting this! It looks sane to me. > > Acked-by: John Stultz <john.stultz@xxxxxxxxxx> > > thanks > -john Best, Sumit.
