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/Kbuild | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 arch/powerpc/Kbuild (limited to 'arch/powerpc/Kbuild') diff --git a/arch/powerpc/Kbuild b/arch/powerpc/Kbuild new file mode 100644 index 000000000..b010ccb07 --- /dev/null +++ b/arch/powerpc/Kbuild @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror -Wa,--fatal-warnings +subdir-asflags-$(CONFIG_PPC_WERROR) := -Wa,--fatal-warnings + +obj-y += kernel/ +obj-y += mm/ +obj-y += lib/ +obj-y += sysdev/ +obj-y += platforms/ +obj-y += math-emu/ +obj-y += crypto/ +obj-y += net/ + +obj-$(CONFIG_XMON) += xmon/ +obj-$(CONFIG_KVM) += kvm/ + +obj-$(CONFIG_PERF_EVENTS) += perf/ +obj-$(CONFIG_KEXEC_CORE) += kexec/ +obj-$(CONFIG_KEXEC_FILE) += purgatory/ + +# for cleaning +subdir- += boot tools -- cgit v1.3.1