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, 35 insertions, 0 deletions

diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec
new file mode 100755
index 000000000..21b319e6c
--- /dev/null
+++ b/scripts/jobserver-exec
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0+
+
+"""
+Determines how many parallel tasks "make" is expecting, as it is
+not exposed via any special variables, reserves them all, runs a subprocess
+with PARALLELISM environment variable set, and releases the jobs back again.
+
+See:
+    https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver
+"""
+
+import os
+import sys
+
+LIB_DIR = "../tools/lib/python"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from jobserver import JobserverExec                  # pylint: disable=C0415
+
+
+def main():
+    """Main program"""
+    if len(sys.argv) < 2:
+        name = os.path.basename(__file__)
+        sys.exit("usage: " + name +" command [args ...]\n" + __doc__)
+
+    with JobserverExec() as jobserver:
+        return jobserver.run(sys.argv[1:])
+
+
+if __name__ == "__main__":
+    sys.exit(main())