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, 86 insertions, 0 deletions

diff --git a/include/net/gtp.h b/include/net/gtp.h
new file mode 100644
index 000000000..c0253c870
--- /dev/null
+++ b/include/net/gtp.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _GTP_H_
+#define _GTP_H_
+
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <net/rtnetlink.h>
+
+/* General GTP protocol related definitions. */
+
+#define GTP0_PORT	3386
+#define GTP1U_PORT	2152
+
+/* GTP messages types */
+#define GTP_ECHO_REQ	1	/* Echo Request */
+#define GTP_ECHO_RSP	2	/* Echo Response */
+#define GTP_TPDU	255
+
+#define GTPIE_RECOVERY	14
+
+struct gtp0_header {	/* According to GSM TS 09.60. */
+	__u8	flags;
+	__u8	type;
+	__be16	length;
+	__be16	seq;
+	__be16	flow;
+	__u8	number;
+	__u8	spare[3];
+	__be64	tid;
+} __attribute__ ((packed));
+
+struct gtp1_header {	/* According to 3GPP TS 29.060. */
+	__u8	flags;
+	__u8	type;
+	__be16	length;
+	__be32	tid;
+} __attribute__ ((packed));
+
+struct gtp1_header_long {	/* According to 3GPP TS 29.060. */
+	__u8	flags;
+	__u8	type;
+	__be16	length;
+	__be32	tid;
+	__be16	seq;
+	__u8	npdu;
+	__u8	next;
+} __packed;
+
+/* GTP Information Element */
+struct gtp_ie {
+	__u8	tag;
+	__u8	val;
+} __packed;
+
+struct gtp0_packet {
+	struct gtp0_header gtp0_h;
+	struct gtp_ie ie;
+} __packed;
+
+struct gtp1u_packet {
+	struct gtp1_header_long gtp1u_h;
+	struct gtp_ie ie;
+} __packed;
+
+struct gtp_pdu_session_info {	/* According to 3GPP TS 38.415. */
+	u8	pdu_type;
+	u8	qfi;
+};
+
+static inline bool netif_is_gtp(const struct net_device *dev)
+{
+	return dev->rtnl_link_ops &&
+		!strcmp(dev->rtnl_link_ops->kind, "gtp");
+}
+
+#define GTP1_F_NPDU	0x01
+#define GTP1_F_SEQ	0x02
+#define GTP1_F_EXTHDR	0x04
+#define GTP1_F_MASK	0x07
+
+struct gtp_ext_hdr {
+	__u8	len;
+	__u8	data[];
+};
+
+#endif