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, 10 insertions, 0 deletions

diff --git a/arch/arc/Kconfig.debug b/arch/arc/Kconfig.debug
new file mode 100644
index 000000000..45add86de
--- /dev/null
+++ b/arch/arc/Kconfig.debug
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config 16KSTACKS
+	bool "Use 16Kb for kernel stacks instead of 8Kb"
+	help
+	  If you say Y here the kernel will use a  16Kb stacksize for the
+	  kernel stack attached to each process/thread. The default is 8K.
+	  This increases the resident kernel footprint and will cause less
+	  threads to run on the system and also increase the pressure
+	  on the VM subsystem for higher order allocations.