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, 31 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/Makefile b/drivers/crypto/ccp/Makefile
new file mode 100644
index 000000000..0424e0856
--- /dev/null
+++ b/drivers/crypto/ccp/Makefile
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CRYPTO_DEV_CCP_DD) += ccp.o
+ccp-objs  := sp-dev.o sp-platform.o
+ccp-$(CONFIG_CRYPTO_DEV_SP_CCP) += ccp-dev.o \
+	    ccp-ops.o \
+	    ccp-dev-v3.o \
+	    ccp-dev-v5.o \
+	    ccp-dmaengine.o
+ccp-$(CONFIG_CRYPTO_DEV_CCP_DEBUGFS) += ccp-debugfs.o
+ccp-$(CONFIG_PCI) += sp-pci.o
+ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += psp-dev.o \
+                                   sev-dev.o \
+                                   tee-dev.o \
+                                   platform-access.o \
+                                   dbc.o \
+                                   hsti.o \
+                                   sfs.o
+
+ifeq ($(CONFIG_PCI_TSM),y)
+ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += sev-dev-tsm.o sev-dev-tio.o
+endif
+
+obj-$(CONFIG_CRYPTO_DEV_CCP_CRYPTO) += ccp-crypto.o
+ccp-crypto-objs := ccp-crypto-main.o \
+		   ccp-crypto-aes.o \
+		   ccp-crypto-aes-cmac.o \
+		   ccp-crypto-aes-xts.o \
+		   ccp-crypto-aes-galois.o \
+		   ccp-crypto-des3.o \
+		   ccp-crypto-rsa.o \
+		   ccp-crypto-sha.o