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 --- drivers/firmware/google/Makefile | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 drivers/firmware/google/Makefile (limited to 'drivers/firmware/google/Makefile') diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile new file mode 100644 index 000000000..8151e323c --- /dev/null +++ b/drivers/firmware/google/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_GOOGLE_SMI) += gsmi.o +obj-$(CONFIG_GOOGLE_COREBOOT_TABLE) += coreboot_table.o +obj-$(CONFIG_GOOGLE_FRAMEBUFFER_COREBOOT) += framebuffer-coreboot.o +obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o +obj-$(CONFIG_GOOGLE_MEMCONSOLE_COREBOOT) += memconsole-coreboot.o +obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o + +# Must come after coreboot_table.o, as this driver depends on that bus type. +obj-$(CONFIG_GOOGLE_CBMEM) += cbmem.o + +vpd-sysfs-y := vpd.o vpd_decode.o +obj-$(CONFIG_GOOGLE_VPD) += vpd-sysfs.o -- cgit v1.3.1