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, 54 insertions, 0 deletions

diff --git a/Documentation/admin-guide/device-mapper/delay.rst b/Documentation/admin-guide/device-mapper/delay.rst
new file mode 100644
index 000000000..a1e673c0e
--- /dev/null
+++ b/Documentation/admin-guide/device-mapper/delay.rst
@@ -0,0 +1,54 @@
+========
+dm-delay
+========
+
+Device-Mapper's "delay" target delays reads and/or writes
+and/or flushes and optionally maps them to different devices.
+
+Arguments::
+
+    <device> <offset> <delay> [<write_device> <write_offset> <write_delay>
+			       [<flush_device> <flush_offset> <flush_delay>]]
+
+Table line has to either have 3, 6 or 9 arguments:
+
+3: apply offset and delay to read, write and flush operations on device
+
+6: apply offset and delay to device, also apply write_offset and write_delay
+   to write and flush operations on optionally different write_device with
+   optionally different sector offset
+
+9: same as 6 arguments plus define flush_offset and flush_delay explicitly
+   on/with optionally different flush_device/flush_offset.
+
+Offsets are specified in sectors.
+
+Delays are specified in milliseconds.
+
+
+Example scripts
+===============
+
+::
+	#!/bin/sh
+	#
+	# Create mapped device named "delayed" delaying read, write and flush operations for 500ms.
+	#
+	dmsetup create delayed --table  "0 `blockdev --getsz $1` delay $1 0 500"
+
+::
+	#!/bin/sh
+	#
+	# Create mapped device delaying write and flush operations for 400ms and
+	# splitting reads to device $1 but writes and flushes to different device $2
+	# to different offsets of 2048 and 4096 sectors respectively.
+	#
+	dmsetup create delayed --table "0 `blockdev --getsz $1` delay $1 2048 0 $2 4096 400"
+
+::
+	#!/bin/sh
+	#
+	# Create mapped device delaying reads for 50ms, writes for 100ms and flushes for 333ms
+	# onto the same backing device at offset 0 sectors.
+	#
+	dmsetup create delayed --table "0 `blockdev --getsz $1` delay $1 0 50 $2 0 100 $1 0 333"