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, 37 insertions, 0 deletions

diff --git a/Documentation/tools/kdoc_parser.rst b/Documentation/tools/kdoc_parser.rst
new file mode 100644
index 000000000..55b202173
--- /dev/null
+++ b/Documentation/tools/kdoc_parser.rst
@@ -0,0 +1,37 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================
+Kernel-doc parser stage
+=======================
+
+C replacement rules used by the parser
+======================================
+
+.. automodule:: lib.python.kdoc.xforms_lists
+   :members:
+   :show-inheritance:
+   :undoc-members:
+
+File handler classes
+====================
+
+.. automodule:: lib.python.kdoc.kdoc_files
+   :members:
+   :show-inheritance:
+   :undoc-members:
+
+Parsed item data class
+======================
+
+.. automodule:: lib.python.kdoc.kdoc_item
+   :members:
+   :show-inheritance:
+   :undoc-members:
+
+Parser classes and methods
+==========================
+
+.. automodule:: lib.python.kdoc.kdoc_parser
+   :members:
+   :show-inheritance:
+   :undoc-members: