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, 29 insertions, 0 deletions

diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
new file mode 100644
index 000000000..b0e1423b0
--- /dev/null
+++ b/scripts/Makefile.gcc-plugins
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+
+gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY)	+= latent_entropy_plugin.so
+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY)		\
+		+= -DLATENT_ENTROPY_PLUGIN
+ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
+    DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable -ULATENT_ENTROPY_PLUGIN
+endif
+export DISABLE_LATENT_ENTROPY_PLUGIN
+
+# All the plugin CFLAGS are collected here in case a build target needs to
+# filter them out of the KBUILD_CFLAGS.
+GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) -DGCC_PLUGINS
+export GCC_PLUGINS_CFLAGS
+
+# Add the flags to the build!
+KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
+
+# Some plugins are enabled outside of this Makefile, but they still need to
+# be included in GCC_PLUGIN so they can get built.
+gcc-plugin-external-$(CONFIG_GCC_PLUGIN_RANDSTRUCT)		\
+	+= randomize_layout_plugin.so
+gcc-plugin-external-$(CONFIG_GCC_PLUGIN_STACKLEAK)		\
+	+= stackleak_plugin.so
+
+# All enabled GCC plugins are collected here for building in
+# scripts/gcc-scripts/Makefile.
+GCC_PLUGIN := $(gcc-plugin-y) $(gcc-plugin-external-y)
+export GCC_PLUGIN