usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmdgrafted

generic_set_cmd() and generic_get_cmd() use the low nibble of
ctrl->bRequest as an index into con->data[]:

    u8 cmd = (ctrl->bRequest & 0x0F);  /* 0 .. 15 */
    ...
    con->data[cmd] = value;            /* OOB when cmd >= 5 */

struct usb_audio_control (include/linux/usb/audio.h) declares data as
a 5-element array, so indices 5 through 15 write (or read) up to 44
bytes past the end of the array on the heap.

A malicious USB host can craft a class-specific SET_CUR / GET_CUR
request with an arbitrary bRequest value, triggering the out-of-bounds
access from an IRQ completion handler with no further preconditions.

Add an ARRAY_SIZE() guard to both functions.

Fixes: c47d7b09891a ("USB: audio: add USB audio class definitions")
Cc: stable <stable@kernel.org>
Reviewed-by: Weibin Liu <liuwb@xiaopeng.com>
Signed-off-by: Liu Chao <liuc63@xiaopeng.com>
Reviewed-by: Ivy Lopez <skunkolee@gmail.com>
Link: https://patch.msgid.link/20260921072551.3708191-1-liuc63@xiaopeng.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/Documentation/driver-api/infrastructure.rst b/Documentation/driver-api/infrastructure.rst
new file mode 100644
index 000000000..ac73e60fb
--- /dev/null
+++ b/Documentation/driver-api/infrastructure.rst
@@ -0,0 +1,107 @@
+Device drivers infrastructure
+=============================
+
+The Basic Device Driver-Model Structures
+----------------------------------------
+
+.. kernel-doc:: include/linux/device.h
+   :internal:
+   :no-identifiers: device_link_state
+
+.. kernel-doc:: include/linux/device/bus.h
+   :identifiers: bus_type bus_notifier_event
+
+.. kernel-doc:: include/linux/device/class.h
+   :identifiers: class
+
+.. kernel-doc:: include/linux/device/driver.h
+   :identifiers: probe_type device_driver
+
+.. kernel-doc:: include/linux/property.h
+
+.. kernel-doc:: include/linux/fwnode.h
+
+Device Drivers Base
+-------------------
+
+.. kernel-doc:: drivers/base/init.c
+   :internal:
+
+.. kernel-doc:: include/linux/device/driver.h
+   :no-identifiers: probe_type device_driver
+
+.. kernel-doc:: drivers/base/driver.c
+   :export:
+
+.. kernel-doc:: drivers/base/core.c
+   :export:
+
+.. kernel-doc:: drivers/base/syscore.c
+   :export:
+
+.. kernel-doc:: include/linux/device/class.h
+   :no-identifiers: class
+
+.. kernel-doc:: drivers/base/class.c
+   :export:
+
+.. kernel-doc:: include/linux/device/faux.h
+   :internal:
+
+.. kernel-doc:: drivers/base/faux.c
+   :export:
+
+.. kernel-doc:: drivers/base/node.c
+   :internal:
+
+.. kernel-doc:: drivers/base/transport_class.c
+   :export:
+
+.. kernel-doc:: drivers/base/dd.c
+   :export:
+
+.. kernel-doc:: include/linux/platform_device.h
+   :internal:
+
+.. kernel-doc:: drivers/base/platform.c
+   :export:
+
+.. kernel-doc:: include/linux/device/bus.h
+   :no-identifiers: bus_type bus_notifier_event
+
+.. kernel-doc:: drivers/base/bus.c
+   :export:
+
+Device Drivers DMA Management
+-----------------------------
+
+.. kernel-doc:: kernel/dma/mapping.c
+   :export:
+
+Device drivers PnP support
+--------------------------
+
+.. kernel-doc:: drivers/pnp/core.c
+   :internal:
+
+.. kernel-doc:: drivers/pnp/card.c
+   :export:
+
+.. kernel-doc:: drivers/pnp/driver.c
+   :internal:
+
+.. kernel-doc:: drivers/pnp/manager.c
+   :export:
+
+.. kernel-doc:: drivers/pnp/support.c
+   :export:
+
+Userspace IO devices
+--------------------
+
+.. kernel-doc:: drivers/uio/uio.c
+   :export:
+
+.. kernel-doc:: include/linux/uio_driver.h
+   :internal:
+