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, 43 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/grackle.c b/arch/powerpc/sysdev/grackle.c
new file mode 100644
index 000000000..7dce8278b
--- /dev/null
+++ b/arch/powerpc/sysdev/grackle.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Functions for setting up and using a MPC106 northbridge
+ * Extracted from arch/powerpc/platforms/powermac/pci.c.
+ *
+ * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
+ * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
+ */
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/io.h>
+#include <asm/pci-bridge.h>
+#include <asm/grackle.h>
+
+#define GRACKLE_CFA(b, d, o)	(0x80 | ((b) << 8) | ((d) << 16) \
+				 | (((o) & ~3) << 24))
+
+#define GRACKLE_PICR1_LOOPSNOOP		0x00000010
+
+static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable)
+{
+	unsigned int val;
+
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	val = in_le32(bp->cfg_data);
+	val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) :
+		(val & ~GRACKLE_PICR1_LOOPSNOOP);
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	out_le32(bp->cfg_data, val);
+	(void)in_le32(bp->cfg_data);
+}
+
+void __init setup_grackle(struct pci_controller *hose)
+{
+	setup_indirect_pci(hose, 0xfec00000, 0xfee00000, 0);
+	if (of_machine_is_compatible("PowerMac1,1"))
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+	if (of_machine_is_compatible("AAPL,PowerBook1998"))
+		grackle_set_loop_snoop(hose, 1);
+}