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, 21 insertions, 0 deletions

diff --git a/fs/smb/server/Makefile b/fs/smb/server/Makefile
new file mode 100644
index 000000000..a3e930605
--- /dev/null
+++ b/fs/smb/server/Makefile
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for Linux SMB3 kernel server
+#
+obj-$(CONFIG_SMB_SERVER) += ksmbd.o
+
+ksmbd-y :=	unicode.o auth.o vfs.o vfs_cache.o server.o ndr.o \
+		misc.o oplock.o connection.o ksmbd_work.o crypto_ctx.o \
+		mgmt/ksmbd_ida.o mgmt/user_config.o mgmt/share_config.o \
+		mgmt/tree_connect.o mgmt/user_session.o smb_common.o \
+		transport_tcp.o transport_ipc.o smbacl.o smb2pdu.o \
+		smb2ops.o smb2misc.o ksmbd_spnego_negtokeninit.asn1.o \
+		ksmbd_spnego_negtokentarg.asn1.o asn1.o compress.o
+
+$(obj)/asn1.o: $(obj)/ksmbd_spnego_negtokeninit.asn1.h $(obj)/ksmbd_spnego_negtokentarg.asn1.h
+
+$(obj)/ksmbd_spnego_negtokeninit.asn1.o: $(obj)/ksmbd_spnego_negtokeninit.asn1.c $(obj)/ksmbd_spnego_negtokeninit.asn1.h
+$(obj)/ksmbd_spnego_negtokentarg.asn1.o: $(obj)/ksmbd_spnego_negtokentarg.asn1.c $(obj)/ksmbd_spnego_negtokentarg.asn1.h
+
+ksmbd-$(CONFIG_SMB_SERVER_SMBDIRECT) += transport_rdma.o
+ksmbd-$(CONFIG_PROC_FS) += proc.o