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/block/rnbd/Makefile | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 drivers/block/rnbd/Makefile (limited to 'drivers/block/rnbd/Makefile') diff --git a/drivers/block/rnbd/Makefile b/drivers/block/rnbd/Makefile new file mode 100644 index 000000000..208e5f865 --- /dev/null +++ b/drivers/block/rnbd/Makefile @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +ccflags-y := -I$(srctree)/drivers/infiniband/ulp/rtrs + +rnbd-client-y := rnbd-clt.o \ + rnbd-clt-sysfs.o + +CFLAGS_rnbd-srv-trace.o = -I$(src) + +rnbd-server-y := rnbd-srv.o \ + rnbd-srv-sysfs.o \ + rnbd-srv-trace.o + +obj-$(CONFIG_BLK_DEV_RNBD_CLIENT) += rnbd-client.o +obj-$(CONFIG_BLK_DEV_RNBD_SERVER) += rnbd-server.o -- cgit v1.3.1