From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- arch/powerpc/boot/gamecube.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 arch/powerpc/boot/gamecube.c (limited to 'arch/powerpc/boot/gamecube.c') diff --git a/arch/powerpc/boot/gamecube.c b/arch/powerpc/boot/gamecube.c new file mode 100644 index 000000000..d030612fd --- /dev/null +++ b/arch/powerpc/boot/gamecube.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * arch/powerpc/boot/gamecube.c + * + * Nintendo GameCube bootwrapper support + * Copyright (C) 2004-2009 The GameCube Linux Team + * Copyright (C) 2008,2009 Albert Herranz + */ + +#include +#include "stdio.h" +#include "types.h" +#include "io.h" +#include "ops.h" + +#include "ugecon.h" + +BSS_STACK(8192); + +void platform_init(unsigned long r3, unsigned long r4, unsigned long r5) +{ + u32 heapsize = 16*1024*1024 - (u32)_end; + + simple_alloc_init(_end, heapsize, 32, 64); + fdt_init(_dtb_start); + + if (ug_probe()) + console_ops.write = ug_console_write; +} + -- cgit v1.3.1