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, 25 insertions, 0 deletions

diff --git a/drivers/net/ipa/Makefile b/drivers/net/ipa/Makefile
new file mode 100644
index 000000000..e148ec3c1
--- /dev/null
+++ b/drivers/net/ipa/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Qualcomm IPA driver.
+
+IPA_REG_VERSIONS	:=	3.1 3.5.1 4.2 4.5 4.7 4.9 4.11 5.0 5.5
+
+# Some IPA versions can reuse another set of GSI register definitions.
+GSI_REG_VERSIONS	:=	3.1 3.5.1 4.0 4.5 4.9 4.11 5.0
+
+IPA_DATA_VERSIONS	:=	3.1 3.5.1 4.2 4.5 4.7 4.9 4.11 5.0 5.2 5.5
+
+obj-$(CONFIG_QCOM_IPA)	+=	ipa.o
+
+ipa-y			:=	ipa_main.o ipa_power.o ipa_reg.o ipa_mem.o \
+				ipa_table.o ipa_interrupt.o gsi.o gsi_reg.o \
+				gsi_trans.o ipa_gsi.o ipa_smp2p.o ipa_uc.o \
+				ipa_endpoint.o ipa_cmd.o ipa_modem.o \
+				ipa_resource.o ipa_qmi.o ipa_qmi_msg.o \
+				ipa_sysfs.o
+
+ipa-y			+=	$(IPA_REG_VERSIONS:%=reg/ipa_reg-v%.o)
+
+ipa-y			+=	$(GSI_REG_VERSIONS:%=reg/gsi_reg-v%.o)
+
+ipa-y			+=	$(IPA_DATA_VERSIONS:%=data/ipa_data-v%.o)