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/microblaze/Kconfig.platform | 71 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 arch/microblaze/Kconfig.platform (limited to 'arch/microblaze/Kconfig.platform') diff --git a/arch/microblaze/Kconfig.platform b/arch/microblaze/Kconfig.platform new file mode 100644 index 000000000..9cf9007ed --- /dev/null +++ b/arch/microblaze/Kconfig.platform @@ -0,0 +1,71 @@ +# SPDX-License-Identifier: GPL-2.0-only +# For a description of the syntax of this configuration file, +# see Documentation/kbuild/kconfig-language.rst. +# +# Platform selection Kconfig menu for MicroBlaze targets +# + +menu "Platform options" + +config OPT_LIB_FUNCTION + bool "Optimized lib function" + default y + help + Turns on optimized library functions (memcpy and memmove). + They are optimized by using word alignment. This will work + fine if both source and destination are aligned on the same + boundary. However, if they are aligned on different boundaries + shifts will be necessary. This might result in bad performance + on MicroBlaze systems without a barrel shifter. + +config OPT_LIB_ASM + bool "Optimized lib function ASM" + depends on OPT_LIB_FUNCTION && (XILINX_MICROBLAZE0_USE_BARREL = 1) + depends on CPU_BIG_ENDIAN + default n + help + Turns on optimized library functions (memcpy and memmove). + They are written in assembly. + +# Definitions for MICROBLAZE0 +comment "Definitions for MICROBLAZE0" + +config KERNEL_BASE_ADDR + hex "Physical address where Linux Kernel is" + default "0x90000000" + help + BASE Address for kernel + +config XILINX_MICROBLAZE0_FAMILY + string "Targeted FPGA family" + default "virtex5" + +config XILINX_MICROBLAZE0_USE_MSR_INSTR + int "USE_MSR_INSTR range (0:1)" + default 0 + +config XILINX_MICROBLAZE0_USE_PCMP_INSTR + int "USE_PCMP_INSTR range (0:1)" + default 0 + +config XILINX_MICROBLAZE0_USE_BARREL + int "USE_BARREL range (0:1)" + default 0 + +config XILINX_MICROBLAZE0_USE_DIV + int "USE_DIV range (0:1)" + default 0 + +config XILINX_MICROBLAZE0_USE_HW_MUL + int "USE_HW_MUL values (0=NONE, 1=MUL32, 2=MUL64)" + default 0 + +config XILINX_MICROBLAZE0_USE_FPU + int "USE_FPU values (0=NONE, 1=BASIC, 2=EXTENDED)" + default 0 + +config XILINX_MICROBLAZE0_HW_VER + string "Core version number" + default "7.10.d" + +endmenu -- cgit v1.3.1