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, 66 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/termbits-common.h b/include/uapi/asm-generic/termbits-common.h
new file mode 100644
index 000000000..4a6a79f28
--- /dev/null
+++ b/include/uapi/asm-generic/termbits-common.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_TERMBITS_COMMON_H
+#define __ASM_GENERIC_TERMBITS_COMMON_H
+
+typedef unsigned char	cc_t;
+typedef unsigned int	speed_t;
+
+/* c_iflag bits */
+#define IGNBRK	0x001			/* Ignore break condition */
+#define BRKINT	0x002			/* Signal interrupt on break */
+#define IGNPAR	0x004			/* Ignore characters with parity errors */
+#define PARMRK	0x008			/* Mark parity and framing errors */
+#define INPCK	0x010			/* Enable input parity check */
+#define ISTRIP	0x020			/* Strip 8th bit off characters */
+#define INLCR	0x040			/* Map NL to CR on input */
+#define IGNCR	0x080			/* Ignore CR */
+#define ICRNL	0x100			/* Map CR to NL on input */
+#define IXANY	0x800			/* Any character will restart after stop */
+
+/* c_oflag bits */
+#define OPOST	0x01			/* Perform output processing */
+#define OCRNL	0x08
+#define ONOCR	0x10
+#define ONLRET	0x20
+#define OFILL	0x40
+#define OFDEL	0x80
+
+/* c_cflag bit meaning */
+/* Common CBAUD rates */
+#define     B0		0x00000000	/* hang up */
+#define    B50		0x00000001
+#define    B75		0x00000002
+#define   B110		0x00000003
+#define   B134		0x00000004
+#define   B150		0x00000005
+#define   B200		0x00000006
+#define   B300		0x00000007
+#define   B600		0x00000008
+#define  B1200		0x00000009
+#define  B1800		0x0000000a
+#define  B2400		0x0000000b
+#define  B4800		0x0000000c
+#define  B9600		0x0000000d
+#define B19200		0x0000000e
+#define B38400		0x0000000f
+#define EXTA		B19200
+#define EXTB		B38400
+
+#define ADDRB		0x20000000	/* address bit */
+#define CMSPAR		0x40000000	/* mark or space (stick) parity */
+#define CRTSCTS		0x80000000	/* flow control */
+
+#define IBSHIFT		16		/* Shift from CBAUD to CIBAUD */
+
+/* tcflow() ACTION argument and TCXONC use these */
+#define TCOOFF		0		/* Suspend output */
+#define TCOON		1		/* Restart suspended output */
+#define TCIOFF		2		/* Send a STOP character */
+#define TCION		3		/* Send a START character */
+
+/* tcflush() QUEUE_SELECTOR argument and TCFLSH use these */
+#define TCIFLUSH	0		/* Discard data received but not yet read */
+#define TCOFLUSH	1		/* Discard data written but not yet sent */
+#define TCIOFLUSH	2		/* Discard all pending data */
+
+#endif /* __ASM_GENERIC_TERMBITS_COMMON_H */