Messages in this thread | | | Date | Fri, 15 Sep 2023 14:23:10 -0600 | Subject | Re: [PATCH] usb: gadget: f_midi: Annotate struct f_midi with __counted_by | From | "Gustavo A. R. Silva" <> |
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On 9/15/23 13:59, Kees Cook wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct f_midi. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: John Keeping <john@keeping.me.uk> > Cc: Peter Chen <peter.chen@nxp.com> > Cc: Hulk Robot <hulkci@huawei.com> > Cc: Allen Pais <allen.lkml@gmail.com> > Cc: Will McVicker <willmcvicker@google.com> > Cc: Davidlohr Bueso <dave@stgolabs.net> > Cc: Zhang Qilong <zhangqilong3@huawei.com> > Cc: linux-usb@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks -- Gustavo
> --- > drivers/usb/gadget/function/f_midi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c > index 2d02f25f9597..033e347554db 100644 > --- a/drivers/usb/gadget/function/f_midi.c > +++ b/drivers/usb/gadget/function/f_midi.c > @@ -99,7 +99,7 @@ struct f_midi { > unsigned int in_last_port; > unsigned char free_ref; > > - struct gmidi_in_port in_ports_array[/* in_ports */]; > + struct gmidi_in_port in_ports_array[] __counted_by(in_ports); > }; > > static inline struct f_midi *func_to_midi(struct usb_function *f) > @@ -1349,6 +1349,7 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) > status = -ENOMEM; > goto setup_fail; > } > + midi->in_ports = opts->in_ports; > > for (i = 0; i < opts->in_ports; i++) > midi->in_ports_array[i].cable = i; > @@ -1359,7 +1360,6 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) > status = -ENOMEM; > goto midi_free; > } > - midi->in_ports = opts->in_ports; > midi->out_ports = opts->out_ports; > midi->index = opts->index; > midi->buflen = opts->buflen;
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