| Message ID | 20220120225243.GA37225@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [next] iio: hw_consumer: Use struct_size() helper in kzalloc() | expand |
On Thu, Jan 20, 2022 at 04:52:43PM -0600, Gustavo A. R. Silva wrote: > Make use of the struct_size() helper instead of an open-coded version, > in order to avoid any potential type mistakes or integer overflows that, > in the worst scenario, could lead to heap overflows. > > Also, address the following sparse warnings: > drivers/iio/buffer/industrialio-hw-consumer.c:63:23: warning: using sizeof on a flexible structure > > Link: https://github.com/KSPP/linux/issues/174 > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Looks good to me. Reviewed-by: Kees Cook <keescook@chromium.org>
On Thu, 20 Jan 2022 15:33:14 -0800 Kees Cook <keescook@chromium.org> wrote: > On Thu, Jan 20, 2022 at 04:52:43PM -0600, Gustavo A. R. Silva wrote: > > Make use of the struct_size() helper instead of an open-coded version, > > in order to avoid any potential type mistakes or integer overflows that, > > in the worst scenario, could lead to heap overflows. > > > > Also, address the following sparse warnings: > > drivers/iio/buffer/industrialio-hw-consumer.c:63:23: warning: using sizeof on a flexible structure > > > > Link: https://github.com/KSPP/linux/issues/174 > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Looks good to me. > > Reviewed-by: Kees Cook <keescook@chromium.org> > Good thing to tidy up, but I'm a little curious why I'm not seeing these reports with latest sparse? Ah. Found it via the report linked CF='-Wflexible-array-sizeof' Probably worth mentioned that in the patch descriptions. I've added it to this one. I'm still setting the sparse report even with this patch. What am I missing? Jonathan
diff --git a/drivers/iio/buffer/industrialio-hw-consumer.c b/drivers/iio/buffer/industrialio-hw-consumer.c index 87d9aabd20c7..fb58f599a80b 100644 --- a/drivers/iio/buffer/industrialio-hw-consumer.c +++ b/drivers/iio/buffer/industrialio-hw-consumer.c @@ -52,7 +52,6 @@ static const struct iio_buffer_access_funcs iio_hw_buf_access = { static struct hw_consumer_buffer *iio_hw_consumer_get_buffer( struct iio_hw_consumer *hwc, struct iio_dev *indio_dev) { - size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long); struct hw_consumer_buffer *buf; list_for_each_entry(buf, &hwc->buffers, head) { @@ -60,7 +59,8 @@ static struct hw_consumer_buffer *iio_hw_consumer_get_buffer( return buf; } - buf = kzalloc(sizeof(*buf) + mask_size, GFP_KERNEL); + buf = kzalloc(struct_size(buf, scan_mask, BITS_TO_LONGS(indio_dev->masklength)), + GFP_KERNEL); if (!buf) return NULL;
Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worst scenario, could lead to heap overflows. Also, address the following sparse warnings: drivers/iio/buffer/industrialio-hw-consumer.c:63:23: warning: using sizeof on a flexible structure Link: https://github.com/KSPP/linux/issues/174 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/iio/buffer/industrialio-hw-consumer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)