* [PATCH][next] iio: hw_consumer: Use struct_size() helper in kzalloc()
@ 2022-01-20 22:52 Gustavo A. R. Silva
2022-01-20 23:33 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2022-01-20 22:52 UTC (permalink / raw)
To: Jonathan Cameron, Lars-Peter Clausen
Cc: linux-iio, linux-kernel, Gustavo A. R. Silva, linux-hardening
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(-)
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;
--
2.27.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH][next] iio: hw_consumer: Use struct_size() helper in kzalloc()
2022-01-20 22:52 [PATCH][next] iio: hw_consumer: Use struct_size() helper in kzalloc() Gustavo A. R. Silva
@ 2022-01-20 23:33 ` Kees Cook
2022-01-22 16:56 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2022-01-20 23:33 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Jonathan Cameron, Lars-Peter Clausen, linux-iio, linux-kernel,
linux-hardening
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>
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][next] iio: hw_consumer: Use struct_size() helper in kzalloc()
2022-01-20 23:33 ` Kees Cook
@ 2022-01-22 16:56 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2022-01-22 16:56 UTC (permalink / raw)
To: Kees Cook
Cc: Gustavo A. R. Silva, Lars-Peter Clausen, linux-iio, linux-kernel,
linux-hardening
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
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-01-22 16:50 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-20 22:52 [PATCH][next] iio: hw_consumer: Use struct_size() helper in kzalloc() Gustavo A. R. Silva
2022-01-20 23:33 ` Kees Cook
2022-01-22 16:56 ` Jonathan Cameron
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).