openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
new file mode 100644
index 000000000..5dccf0e45
--- /dev/null
+++ b/drivers/usb/musb/Makefile
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# for USB OTG silicon based on Mentor Graphics INVENTRA designs
+#
+
+# define_trace.h needs to know how to find our header
+CFLAGS_musb_trace.o	:= -I$(src)
+
+obj-$(CONFIG_USB_MUSB_HDRC) += musb_hdrc.o
+
+musb_hdrc-y := musb_core.o musb_trace.o
+
+musb_hdrc-$(CONFIG_USB_MUSB_HOST)$(CONFIG_USB_MUSB_DUAL_ROLE) += musb_virthub.o musb_host.o
+musb_hdrc-$(CONFIG_USB_MUSB_GADGET)$(CONFIG_USB_MUSB_DUAL_ROLE) += musb_gadget_ep0.o musb_gadget.o
+musb_hdrc-$(CONFIG_DEBUG_FS)			+= musb_debugfs.o
+
+# Hardware Glue Layer
+obj-$(CONFIG_USB_MUSB_OMAP2PLUS)		+= omap2430.o
+obj-$(CONFIG_USB_MUSB_DSPS)			+= musb_dsps.o
+obj-$(CONFIG_USB_MUSB_TUSB6010)			+= tusb6010.o
+obj-$(CONFIG_USB_MUSB_DA8XX)			+= da8xx.o
+obj-$(CONFIG_USB_MUSB_UX500)			+= ux500.o
+obj-$(CONFIG_USB_MUSB_JZ4740)			+= jz4740.o
+obj-$(CONFIG_USB_MUSB_SUNXI)			+= sunxi.o
+obj-$(CONFIG_USB_MUSB_MEDIATEK)      		+= mediatek.o
+obj-$(CONFIG_USB_MUSB_POLARFIRE_SOC)		+= mpfs.o
+
+# the kconfig must guarantee that only one of the
+# possible I/O schemes will be enabled at a time ...
+# PIO only, or DMA (several potential schemes).
+# though PIO is always there to back up DMA, and for ep0
+
+musb_hdrc-$(CONFIG_USB_INVENTRA_DMA)		+= musbhsdma.o
+musb_hdrc-$(CONFIG_USB_TUSB_OMAP_DMA)		+= tusb6010_omap.o
+musb_hdrc-$(CONFIG_USB_UX500_DMA)		+= ux500_dma.o
+musb_hdrc-$(CONFIG_USB_TI_CPPI41_DMA)		+= musb_cppi41.o