From 9062d50e75c24dc7911be05c9b1719b3b256af15 Mon Sep 17 00:00:00 2001 From: Liu Chao Date: Mon, 21 Sep 2026 15:25:51 +0800 Subject: usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd 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 Reviewed-by: Weibin Liu Signed-off-by: Liu Chao Reviewed-by: Ivy Lopez Link: https://patch.msgid.link/20260921072551.3708191-1-liuc63@xiaopeng.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/lib/string.S | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 arch/powerpc/lib/string.S (limited to 'arch/powerpc/lib/string.S') diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S new file mode 100644 index 000000000..c3f5e7d31 --- /dev/null +++ b/arch/powerpc/lib/string.S @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * String handling functions for PowerPC. + * + * Copyright (C) 1996 Paul Mackerras. + */ +#include +#include +#include + + .text + +_GLOBAL(strncmp) + PPC_LCMPI 0,r5,0 + beq- 2f + mtctr r5 + addi r5,r3,-1 + addi r4,r4,-1 + .balign IFETCH_ALIGN_BYTES +1: lbzu r3,1(r5) + cmpwi 1,r3,0 + lbzu r0,1(r4) + subf. r3,r0,r3 + beqlr 1 + bdnzt eq,1b + blr +2: li r3,0 + blr +EXPORT_SYMBOL(strncmp) + +_GLOBAL(memchr) + PPC_LCMPI 0,r5,0 + beq- 2f + mtctr r5 + addi r3,r3,-1 + .balign IFETCH_ALIGN_BYTES +1: lbzu r0,1(r3) + cmpw 0,r0,r4 + bdnzf 2,1b + beqlr +2: li r3,0 + blr +EXPORT_SYMBOL(memchr) -- cgit v1.3.1