6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook [ Upstream commit 182717026e2c8e6cc3b5757f601c3fee15f64ecb ] 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 Cc: John Keeping Cc: Peter Chen Cc: Hulk Robot Cc: Allen Pais Cc: Will McVicker Cc: Davidlohr Bueso Cc: Zhang Qilong Cc: linux-usb@vger.kernel.org Reviewed-by: "Gustavo A. R. Silva" Link: https://lore.kernel.org/r/20230915195938.never.611-kees@kernel.org Signed-off-by: Kees Cook Stable-dep-of: 7e07d3e4c389 ("usb: gadget: f_midi: initialize work in f_midi_alloc()") Signed-off-by: Sasha Levin --- 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 680651e91a523..48c87f5b1a4e1 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) @@ -1359,6 +1359,7 @@ 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; @@ -1369,7 +1370,6 @@ 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; -- 2.53.0